JP3821004B2

JP3821004B2 - Sacrificial anode inspection method and inspection apparatus

Info

Publication number: JP3821004B2
Application number: JP2002031617A
Authority: JP
Inventors: ルリ樋口
Original assignee: Suzuki Motor Corp
Current assignee: Suzuki Motor Corp
Priority date: 2002-02-08
Filing date: 2002-02-08
Publication date: 2006-09-13
Anticipated expiration: 2022-02-08
Also published as: JP2003232766A

Description

【０００１】
【発明の属する技術分野】
本発明は、犠牲陽極の検査方法及び検査装置に関し、さらに詳しくは、犠牲陽極の評価（特に、塗装を施した金属面に及ぼす効果などの評価）や犠牲陽極の効果が有効な範囲を判定するための検査方法及び検査装置に関するものである。
【０００２】
【従来の技術】
プロペラを搭載する船外機本体（防食対象物）の耐食性を向上させる方法の１つとして、船外機本体に犠牲陽極を設置する方法がある。船外機は、通常の塗装された金属よりも苛酷な環境で使用されるため、その本体（船外機本体）に表面処理や塗装などを施すことにより船外機本体の耐食性を高めるようにしている。これに加えて、犠牲陽極の効果も併せて発揮させることにより、船外機本体の耐食性を顕著に向上させるようにしている。なお、犠牲陽極は、船外機本体の材質よりも溶解しやすい性質を持つものであり、自らが溶解し、船外機本体側に電子を供給することにより船外機本体の防食を図る役目を担うものである。
【０００３】
【発明が解決しようとする課題】
船外機本体の耐食性を評価するにあたっては、塩水噴霧試験や複合サイクル試験、浸食腐食試験（評価する部品を塩溶液中に浸漬して行なう試験）などを行なうようにしているが、船外機本体そのものの耐食性を高めるための処理が施されているため、塩水噴霧試験、複合サイクル試験、若しくは浸食腐食試験を行なう際には長期間の試験時間が必要である。
【０００４】
また、この犠牲陽極の設置位置については経験と勘に頼ることが多いのが実状である。流電陽極（犠牲陽極）Ａから防食対象物Ｂに流れる電流Ｉの分布は図１１（ａ），（ｂ）に示すように表されることが多く、この分布や特性データなどを元に犠牲陽極の設置位置を選択することが多いが、実際に犠牲陽極から船外機本体までの電流経路の距離以外に、船外機本体や犠牲陽極の形状，船外機本体の材質，下地処理，及び塗装の種類や膜厚などの影響を受けるため、その効果を十分に発揮できていない場合がある。
【０００５】
一方、図１２に示すように電解質溶液１００中に参照極１０１を浸漬すると共に電解質溶液１０２中に犠牲陽極１０３及び対極１０４を浸漬し、これらの電解質溶液１００，１０２をルギン管１０５を介して塩橋してポテンショスタット１０６にて電位を計測することにより、犠牲陽極１０３の特性を測定することは可能である。しかし、このような実験を行なうには、検査対象物（被検査物）を試験片として切り出す必要がある。また、図１３に示すように、検査対象物である船外機本体１０７の全体を電解質溶液１０８（海水，人口海水など）中に浸漬して犠牲陽極１０３の特性を測定する場合には、測定対象箇所以外の多くの部分も電解質溶液１０８中に浸漬されるため、測定対象箇所だけを測定しているか定かではなくなる。さらに、船外機本体１０７側へ及ぼす犠牲陽極１０３の影響を純粋に把握するには、測定用の電極類を船外機本体１０７に近接して配置する必要があるが、そのようにしても他の因子からの影響が多く、犠牲陽極１０３の適正な評価が困難である。
【０００６】
なお、平面のサンプルを用い、そのサンプルの全体を電解質溶液中に浸漬して測定することによって概算は可能である。しかしながら、実際の船外機本体１０７の表面は平面だけでなく複雑に湾曲した形状（立体的）の部分もあり、しかも影となる裏側の部分も生じるため、単純に計算により犠牲陽極１０３の影響が船外機本体１０７に対してどの程度、どの範囲まで及んでいるのかについて把握することは難しい。また、算出した効果が、実際のものと一致しないこともある。
【０００７】
一方、特開平７−２０８９１０には、流電楊極の残余寿命を測定するために流電楊極の表面積を測定する方法及び装置が開示されているが、この方法及び装置は、本発明に係る方法及び装置のように犠牲陽極そのものの設置位置、量などを決定するものとは異なるものである。
【０００８】
本発明は、上述の如き実状に鑑みてなされたものであって、その目的は、実際の船外機本体に対する犠牲陽極の影響
（効果）について、犠牲陽極が取付けられた船外機本体の全体を浸漬することなくしかも正確に短時間で評価を行なうことができる犠牲陽極の検査方法及び検査装置を提供することにある。
【０００９】
【課題を解決するための手段】
上述の目的を達成するために、本発明に係る犠牲陽極の検査方法では、第１の容器に充填された電解質溶液に、検査対象物に電気的に接続された犠牲陽極を浸漬する一方、前記第１の容器とは別の第２の容器に電解質溶液を充填すると共に、前記第１の容器内の電解質溶液と前記第２の容器内の電解質溶液とを塩橋若しくは液絡し、前記第２の容器及び電解質溶液から構成された検査ユニットを検査対象物の欠陥部に対応配置して前記犠牲陽極に流れる電流を検出し、この検出電流に基づいて前記犠牲陽極の評価を行なうようにしている。
また、本発明に係る犠牲陽極の検査方法では、前記検査ユニットを前記検査対象物の複数箇所の欠陥部にそれぞれ対応配置し、その際に前記犠牲陽極にそれぞれ流れる電流の電流値若しくは電流密度に基づいて前記犠牲陽極の効果が有効な範囲を判定するようにしている。
また、本発明に係る犠牲陽極の検査方法では、第１の容器に充填された電解質溶液に、検査対象物に電気的に接続された犠牲陽極を浸漬する一方、前記第１の容器とは別の第２の容器に電解質溶液を充填すると共に前記第２の容器内の電解質溶液に参照極を浸漬し、前記第１の容器内の電解質溶液と前記第２の容器内の電解質溶液とを塩橋若しくは液絡し、前記第２の容器，参照極，及び電解質溶液から構成された検査ユニットを検査対象物の欠陥部に対応配置して前記検査対象物の欠陥部の電位を検出し、この検出電位に基づいて前記犠牲陽極の評価を行なうようにしている。
また、本発明に係る犠牲陽極の検査方法では、前記検査ユニットを前記検査対象物の複数箇所の欠陥部にそれぞれ対応配置し、その際の前記検査対象物の欠陥部の各所における電位に基づいて前記犠牲陽極の効果が有効な範囲を判定するようにしている。
また、本発明に係る犠牲陽極の検査装置では、
（ａ）第１の容器内に充填された電解質溶液の中に犠牲陽極を浸漬して成る第１のセル構成部、
（ｂ）前記第１の容器とは別の第２の容器と、前記第２の容器内に密封状態で充填された電解質溶液とを有する第２のセル構成部としての検査ユニット、
（ｃ）前記第１の容器内の電解質溶液と前記第２の容器内の電解質溶液とを相互に塩橋若しくは液絡する電気接続部、
（ｄ）前記犠牲電極に流れる電流を検出する電流検出手段、
をそれぞれ具備し、
前記検査ユニットを検査対象物の欠陥部に対応配置したときに前記犠牲陽極に流れる電流を前記電流検出手段にて検出し、この検出電流に基づいて前記犠牲陽極を評価するようにしている。
また、本発明に係る犠牲陽極の検査装置では、
（ａ）第１の容器内に充填された電解質溶液の中に犠牲陽極を浸漬して成る第１のセル構成部、
（ｂ）前記第１の容器とは別の第２の容器と、前記第２の容器内に密封状態で充填された電解質溶液と、前記第２の容器内の電解質溶液に浸漬された参照極とを有する第２のセル構成部としての検査ユニット、
（ｃ）前記第１の容器内の電解質溶液と前記第２の容器内の電解質溶液とを相互に塩橋若しくは液絡する電気接続部、
（ｄ）前記検査対象物の欠陥部における電位を検出する電位検出手段、
をそれぞれ具備し、
前記検査ユニットを検査対象物の欠陥部に対応配置したときの前記検査対象物の欠陥部の電位を前記電位検出手段にて検出し、この検出電位に基づいて前記犠牲陽極を評価するようにしている。
また、本発明に係る犠牲陽極の検査装置では、前記参照極に接続されたリード線、及び、前記検査対象物の欠陥部に接続されたリード線を前記電位検出手段に接続して前記検査対象物の欠陥部における電位を計測し、その検出電位に基づいて前記犠牲陽極の評価を行なうように構成している。
また、本発明に係る犠牲陽極の検査装置では、前記検査ユニットの第２の容器に、前記第１及び第２の容器内の電解質溶液を相互に連通するための第１のパイプ部材、並びに、前記第２の容器の外部からその内部に電解質溶液を導入して前記第２の容器内の圧力調整，前記第２の容器のエア抜き，及び前記第２の容器への前記電解質溶液の供給制御を行なうための第２のパイプ部材を取付けるようにしている。
また、本発明に係る犠牲陽極の検査装置では、前記第２の容器内への前記第１のパイプ部材の挿入長さを短く設定して前記第１のパイプ部材の一端部を前記第２の容器の天壁部の近傍位置に配置すると共に、前記第２の容器内への前記第２のパイプ部材の挿入長さを前記第１のパイプ部材の挿入長さよりも長く設定して前記第２のパイプ部材の一端部を前記第２の容器の底壁部の近傍位置に配置するようにしている。
また、本発明に係る犠牲陽極の検査装置では、前記検査ユニットの第２の容器の底壁部に測定用開口を設け、前記測定用開口に前記参照極を対応配置すると共に、前記測定用開口内に多孔質体を配置して前記測定用開口を前記多孔質体にて閉塞するようにしている。
【００１０】
ここで、本発明の実施形態を説明する前に、本発明の原理について簡単に説明すると次の通りである。まず、図１４（ａ）に示すように異種（２種類）の金属材料から成る金属平板１，２を塩化カリウム溶液などの電解質溶液３の中に浸漬してこれら両者を導線４で繋ぐと、イオン化傾向（電解質溶液中の金属・合金の活性の順列）の相対的に大きな金属材料から成る金属平板１から導線４を通り、イオン化傾向（電解質溶液中の金属・合金の活性の順列）の相対的に小さな金属材料から成る金属平板２に電子ｅ^-が供給される。この時、金属平板１はアノード（陽極）、金属平板２はカソード（陰極）となり、金属平板１は金属平板２に対して犠牲陽極としての機能を持つこととなる。このことは、電解質溶液３を図１４（ｂ）に示す如く金属平板１用の電解質溶液３ａと金属平板２用の電解質溶液３ｂとに別々に分離しても、これらの電解質溶液３ａ，３ｂを塩橋若しくは液絡用エレメント５で相互に繋ぐようにすれば上記と同様の結果が得られる。
【００１１】
また、図１５（ａ）に示すように、欠陥部６をもつ塗装金属である防食対象物７を犠牲陽極８に導線９を介して相互に接続して電解質溶液３の中に浸漬した場合には、犠牲陽極８が溶解することにより導線９を通って電子が流れる。そして、この際の電流Ｉは、図１５（ａ）において破線の矢印で示すような分布となり、防食対象物７に存在する欠陥部６に集中して流れるようになる。この時、図１５（ｂ）に示す如き回路ができていると考えることができる。なお、この場合、陽極電極としての犠牲電極８は、電位の発生源として電池とみなし、図１５（a）の回路においては電池Ｅで示される。
【００１２】
ここで、防食対象物７を構成する金属材料Ｃの抵抗をｒ、防食対象物７の塗装Ｄの抵抗（塗装抵抗）をｒ’、電解質溶液３の抵抗をｒ''、全抵抗をＲとすると、全体の電流Ｉは、下記の式（１）で表すことができる。
Ｉ＝Ｅ／（ｒ＋ｒ’＋ｒ''） ……… （１）
【００１３】
同様に、欠陥部６が１箇所だけに存在する場合であって、かつ、犠牲陽極８の設置予定位置Ｐから欠陥部６までの距離が短い場合（犠牲陽極８の設置予定位置Ｐと欠陥部６とが近い場合）には、図１６（ａ）に示すような回路で表すことができ、そして犠牲陽極８の設置予定位置Ｐから欠陥部６までの距離が長い場合（犠牲陽極８の設置予定位置Ｐと欠陥部６とが遠い場合）には、図１６（ｂ）で示すような回路で表すことができる。なお、塗装Ｄの抵抗ｒ’は、防食対象物７の塗装が均一であるならば一定値であり、防食対象物７を構成する金属材料Ｃの抵抗ｒ、電解質溶液３の抵抗ｒ''は、前記距離が長いほど大きくなる。
【００１４】
犠牲陽極８の設置予定位置Ｐと欠陥部６とが近い位置にある場合の全抵抗Ｒ_aは、その場合の前記抵抗ｒをｒ_aとすれば、下記の式（２）で表される。
Ｒ_a＝ｒ_a＋ｒ’＋ｒ_a'' ……… （２）
また、犠牲陽極８の設置予定位置Ｐと欠陥部６とが遠い位置にある場合の全抵抗Ｒ_bは、その場合の前記抵抗ｒをｒ_bとすれば、下記の式（３）で表される。
Ｒ_b＝ｒ_b＋ｒ’＋ｒ_b'' ……… （３）
従って、その際に欠陥部６に流れる電流Ｉ_a，Ｉ_bは、下記の式（４），（５）にそれぞれ表される如くとなる。
Ｉ_a＝Ｅ／Ｒ_a ……… （４）
Ｉ_b＝Ｅ／Ｒ_b ……… （５）
【００１５】
また、欠陥部６が複数箇所に存在する場合には、図１６（ｃ）で示すような回路で表すことができる。この時の全抵抗Ｒ_cは、下記の式（６）でされる。
Ｒ_c＝｛（ｒ_a＋ｒ’＋ｒ_a''）×（ｒ_b＋ｒ’＋ｒ_b''）｝／｛（ｒ_a＋ｒ’＋ｒ_a''）＋（ｒ_b＋ｒ’＋ｒ_b''）｝ ……… （６）
そして、その際の電流Ｉ_cは、下記の式（７）で表される。
Ｉ_c＝Ｅ／Ｒ_c ……… （７）
従って、欠陥部６が存在する各箇所に流れる電流値Ｉをそれぞれ測定してこれらの測定値に基づいて、防食に必要な電流値を下回らず、しかも過防食とならないような、犠牲陽極８の効果を十分に発揮できる犠牲陽極８の位置，量，並びに表面積を決定することができる。
【００１６】
これらは電気化学的な測定であり、電流値、電圧値の測定を短時間で行なうことができ、その電流値又は電圧値（電位値）に基づいて、従来の評価法として用いられている塩水噴霧試験や複合サイクル試験（例えば１０００時間程度の評価時間を要する）よりも遥かに短時間で犠牲電極８の評価を行なうことが可能である。
【００１７】
【発明の実施の形態】
以下、本発明の実施形態について図１〜図１０を参照して説明する。
【００１８】
図１及び図２は、本発明に係る犠牲陽極の検査方法を施行するための検査装置（セル装置）１０を示すものであって、この検査装置１０は、船外機本体１１の欠陥部１２に対する犠牲陽極の効果並びに影響範囲（有効範囲）を測定して評価するための装置である。本実施形態の検査装置１０は、図１に示すように、第１の容器１３に充填された電解質溶液（例えば、塩化ナトリウム溶液）１５ａに、船外機本体１１にリード線１４にて電気的に接続された犠牲陽極１６を浸漬する一方、第１の容器１３とは別の第２の容器１７に電解質溶液（例えば、塩化ナトリウム溶液）１５ｂを充填すると共に第２の容器内１７の電解質溶液１５ｂに参照極１８を浸漬し、第１の容器１３内の電解質溶液１５ａと第２の容器１７内の電解質溶液１５ｂとを塩橋若しくは液絡して成るものであり、第２の容器１７，参照極１８，及び電解質溶液１５ｂにて構成された検査ユニット（セル構成体）２０を検査対象物である船外機本体１１の欠陥部１２に対応配置してその際に犠牲陽極１６による電流・電位に基づいて犠牲陽極１６の評価を行なうようにしたものである。
【００１９】
さらに具体的に述べると、上述の検査装置１０は、第１の容器１３内に充填された電解質溶液１５ａの中に犠牲陽極１６を浸漬して成る第１のセル構成部２１、第１の容器１３とは別の第２の容器１７と、第２の容器内に密封状態で充填された電解質溶液１５ｂと、第２の容器１７内の電解質溶液１５ｂに浸漬された参照極１８とを有する検査ユニットとしての第２のセル構成部２２、第１の容器１３内の電解質溶液１５ａと第２の容器１７内の電解質溶液１５ｂとを相互に塩橋若しくは液絡する電気接続部２３から成る。そして、犠牲電極１６に流れる電流を検出するために図１，図３及び図４に示すようにリード線１４に設けられた電流検出手段としての電流計２４が備えられている。さらに、電位検出手段としてのポテンショスタット２５が付設されており、図５に示す場合には、参照極１８に接続されたリード線４０、及び、船外機本体１１の欠陥部１２に接続されたリード線４２がポテンショスタット２５にそれぞれ接続されている。一方、図６に示す場合には、参照極１８に接続されたリード線４０がポテンショスタット２５に接続されると共に、船外機本体１１の複数の欠陥部１２にそれぞれ接続された複数のリード線４２が切替器６２を介してポテンショスタット２５に接続されている。
【００２０】
また、上述の第２のセル構成部２２の第２の容器１７は、図２に明示するように、上部及び下部に開口部を有する筒状の枠体２６と、この枠体２６の上部及び下部にそれぞれ嵌着されたシリコン栓２７ａ，２７ｂとから成る密封容器であって、その内部に電解質溶液１５ｂが完全密封状態で充填されている。そして、既述の参照極１８がシリコン栓２７ａ（第２の容器１７の天壁部）に貫通されて第２の容器１７内の電解質溶液１５ｂ中に浸漬されている。さらに、上述のシリコン栓２７ａには、第１及び第２の容器１３，１７内の電解質溶液１５ａ，１５ｂを相互に電気的に連通するための第１のパイプ部材２８、並びに、第２の容器１３の外部からその内部に新たな電解質溶液１５ｂを導入して第２の容器１７内の圧力調整及び電解質溶液１５ｂの供給調整を行ないかつ第２の容器１７内のエアを抜くための第２のパイプ部材２９が貫通状態で取付けれられている。すなわち、第２の容器１７の天壁部を構成するシリコン栓２７ａには、例えばテフロン（登録商標）製の第１及び第２のパイプ部材２８，２９が貫通配置されており、第１のパイプ部材２８の一端部がシリコン栓２７ａの近くで電解質溶液１５ｂ中に浸漬されると共に、第２のパイプ部材２９の一端部がシリコン栓２７ａに対向するシリコン栓２７ｂ（第２の容器１７の底壁部）の近くに配置されている。従って、第２の容器２７内における２種のパイプ部材２８，２９の電解質溶液１５ｂ中への浸漬長さは、第１のパイプ部材２８については、第２の容器１７のシリコン栓２７ａ（天壁部）の近くでその先端部が終端となるように相対的に短く設定され、第２のパイプ部材２９については、第１のパイプ部材２８の挿入長さよりも長く設定されて、その一端部がセル測定面側端部となる第２の容器１７のシリコン栓２７ｂの近傍位置に配置されている。
【００２１】
そして、第２の容器１７の外部に配置される第１のパイプ部材２８の他端部には、塩橋若しくは液絡用エレメント３０の一端部が接続されている。この塩橋若しくは液絡用エレメント３０としては、例えばチューブ内に塩化カリウム入りの寒天を固めた状態で入れたものが使用され、常に同じ抵抗値を示すように調整されている。一方、塩橋若しくは液絡用エレメント３０の他端部は、既述の第１の容器１３内の電解質溶液１５ａに浸漬された状態で固定されている。
【００２２】
また、第２の容器１７のシリコン栓２７ｂ（セル測定面底壁部）には、ほぼ中央箇所に測定用開口３１が形成されており、連続気孔を有する多孔質体３２が測定用開口３１内に挿入配置されている。そして、第２の容器１７の外部で第２のパイプ部材２９に設けられたシリンジ３３により第２の容器１７の内部の圧力を調整すると共に、測定用開口３１ヘの電解質溶液１５ｂの供給を制御することによって、測定対応面α（図１及び図２参照）以外への電解質溶液１５ｂの漏れを防ぐように構成されている。一方、既述の参照極１８の先端は前記測定用開口３１の近傍の真上位置に配置されると共に、前記開口面測定用開口３１からの距離すなわち第２の容器１７の底面側のシリコン栓２７ｂの測定対応面αからの距離は最小限に設定されている。因みに、測定用開口３１は、前記測定対応面αの中央位置に配置されると共に、検査対象物の表面が曲面である場合にも対応できるようにその面積が約１cm²に設定され、その全面積部分が多孔質体３２で閉塞されて第２の容器１７内の電解質溶液１５ｂの漏洩が阻止されるようになっている。なお、この多孔質体３２の厚さは、電解質溶液１５ｂを通過させることなく確実に保持しつつ、参照極１８と測定対応面αとの間の距離を最短にできるような厚さ（好ましくは、１ｍｍ〜１５ｍｍ）に選定されている。
【００２３】
また、図１及び図２に示すように、第２の容器１７の測定対応面αには、測定用開口３１以外の部分に電解質溶液１５ｂが接するのを防ぐためにＯリング３４，３５が配設されており、これにより、測定対応面αが検査対象物の測定面に密着し得るように構成されている。なお、測定対応面に当たる部分は、枠体２６を密閉できる部材とし、かつ、検査対象物の測定面を傷つけることの無い材質のシリコン栓２７ｂなどの部材にて構成されている。
【００２４】
次に、上述の検査装置１０を使用して船外機本体１１の犠牲陽極１６の検査（評価）を行なう際の手順について述べると、以下の通りである。まず、防食対象物である船外機本体１１を使用状況と同じように設置し、図３及び図４に示すように犠牲陽極設置予定位置Ｐにリード線１４の一端部を接続する。そして、犠牲陽極１６にリード線１４の他端部を接続し、その犠牲陽極１６を第１の容器１３内の電解質溶液１５ａ中にリード線１４が浸らない状態の下で浸漬する。一方、図３若しくは図４に示すように、防食対象物である船外機本体１１の１箇所若しくは複数箇所に、クロスカットなどのような手法で人工的な欠陥部（欠損部）１２を形成する。次いで、第２のセル構成部２２である検査ユニット２０を移動させて検査ユニット２０の測定対応面αをＯリング３４，３５を介して船外機本体１１の表面上に配置すると共に、測定用開口３１にて欠陥部１２を覆った状態に設置する（図３及び図４参照）。なお、この際、船外機本体１１と犠牲陽極１６とは、第１及び第２の容器１３，１７内の電解質溶液１５ａ，１５ｂの間を繋ぐ塩橋若しくは液絡用エレメント３０を介して相互に電気的に接続した状態に設定する。
【００２５】
次に、この状態の下で、リード線１４に流れる電流すなわち犠牲陽極１６に流れる電流の電流値・電流密度を電流計２４にて検出（測定）する。かくして、欠陥部１２の位置を適宜に変更することにより、船外機本体１１の各位置（犠牲陽極１６からそれぞれ異なった距離を隔てた複数箇所）における犠牲陽極１６の効果を、電流値・電流密度で表すことができる。すなわち、犠牲陽極１６の表面積及び量、犠牲陽極設置予定位置Ｐから欠陥部１２までの距離などを適宜に変更し、このときの電流値・電流密度から、船外機本体１１における電流の通り易さの程度を把握することができる。しかして、その電流密度が、計算上の防食に必要な電流密度を上回る場合には、その部分（箇所）まで犠牲陽極１６の効果が及んでいることがわかり、その電流密度が、計算上の防食に必要な電流密度を下回る場合には、その部分（箇所）まで犠牲陽極１６の効果が及んでいないことがわかる。従って、犠牲陽極の効果が有効な範囲を判定することができ、犠牲陽極１６の大きさ，量，及び表面積の検討を行なったり、或いは、犠牲陽極１６の設置位置の検討などを行なうことが可能である。
【００２６】
また、図５及び図６は、欠陥部１２における電位も併せて測定するようにした実施形態を示している。図５に示す如く欠陥部１２を１箇所としたサンプルの場合には、上記の場合と同様に犠牲陽極１６との接続を継続したままで、欠陥部１２にリード線４２を接続し、このリード線４２、並びに、参照極１８のリード線４０をポテンショスタット２５に接続する。また、図６に示す如く欠陥部１２を複数箇所としたサンプルの場合には、上記の場合と同様に犠牲陽極１６との接続を継続したままで、欠陥部１２の各々にリード線４２をそれぞれ接続し、これらのリード線４２、並びに、参照極１８のリード線４０を切替器６２を介してポテンショスタット２５に接続する。このようにすれば、欠陥部１２のそれぞれの部位での電位をポテンショスタット２５にて測定することができ、計測された電位に基づいて犠牲陽極の評価を行なうことができる。
【００２７】
次に、本発明の実施例及び比較例につき述べると、以下の通りである。本発明の実施例では、電解質溶液１５ａ，１５ｂとして３％塩化ナトリウム水溶液を用い、犠牲陽極１６の面積を１cm²とした。サンプルとしてはアルミダイカスト材に塗装を施したものを使用し、犠牲陽極設置予定位置Ｐから欠陥部１２までの実測距離を５cm，１０cm，１５cm，２０cmとして測定を行なった。塩橋若しくは液絡用エレメント３０の長さは欠陥部１２までの空間距離に設定した。
【００２８】
各例の詳細を下記の表１に示す。
【表１】

【００２９】
犠牲陽極設置予定位置Ｐから欠陥部１２までの距離と、各欠陥部１２に流れる電流の電流密度値との関係（実験結果）を下記の表２に示す。
【表２】

【００３０】
図９は、上記の表２の実験結果をプロットしたグラフである。なお、図９のグラフの横軸は犠牲陽極１６からの距離、その縦軸は防食に必要な電流密度を１とした場合のそれぞれの電流密度比である。
【００３１】
実施例１及び比較例１は、欠陥部１２が１箇所だけに存在する場合を想定したサンプルについて測定したものである。実施例１のセル方式及び比較例１の浸漬方式においては、共に、同レベルの電流値・電流密度値を示し、犠牲陽極１６からの距離が遠くなるほどその数値は小さくなった。このことは、距離の増加に比例して犠牲陽極１６の効果が徐々に減少していることを示している。
【００３２】
また、実施例２及び比較例２は、欠陥部１２が複数箇所に存在する場合を想定したサンプルについて測定したものである。実施例２のセル方式及び比較例２の浸漬方式においては、共に、同レベルの電流値・電流密度値を示し、距離の増加に伴う犠牲陽極１６の効果の減少傾向は方式によらず同じであった。このことからも、距離の増加に比例して犠牲陽極の効果が減少していることがわかった。
【００３３】
欠陥部１２が複数箇所に存在する場合は、近いところから電流を供給していくため、１箇所のみに欠陥部１２が存在する場合に測定したのと同じ距離条件の下でその場合よりも低い電流密度比を示した。電流密度が小さければ防食の効果が低く、大き過ぎると過防食となることから、両者の兼ね合いを考え、犠牲陽極１６の設置位置を本発明のセル方式により簡易に決定することができる。
【００３４】
実施例３の場合における電位の測定結果を下記の表３に示す。
【表３】

【００３５】
図１０は、上記の表３の実験結果をプロットしたグラフである。なお、図１０のグラフの縦軸はサンプル素材の金属の自然電位であり、その横軸は犠牲陽極１６からの距離である。各欠陥部１２の防食に必要とされる電位は、防食対象物（船外機本体１１）を構成する金属の自然電位より０．２Ｖ〜０．３Ｖほど低いことが求められる。実施例３のサンプルでは、図１０のグラフ内において多数のドットで示す範囲Ｍが期待される電位の範囲である。測定結果から、距離が遠くなっても、この犠牲陽極１６がサンプルの防食に十分な電位を保つことが確認できた。また、距離による電位の変化は小さいが、セル方式でも読み取ることができた。
【００３６】
以上により、本発明のセル方式を用いることにより浸漬方式と同等の測定をより簡易に行なうことができることがわかり、本発明の期待する効果（セル方式の有効性）が確認された。
【００３７】
以上、本発明の一実施形態について述べたが、本発明はこの実施形態に限定されるものではなく、本発明の技術的思想に基づいて各種の変形及び変更が可能である。例えば、検査ユニット１７（第２のセル構成部２２）の測定用開口３１を船外機本体１１の欠陥部１２に密着状態で対応配置させるための構造は、既述のような多孔質体３２を利用した構造に限定されるものではなく、検査ユニット１７をクランプで船外機本体１１に設置する構造、検査ユニット１７の底面に磁石を埋め込みかつ船外機本体１１の側にも磁場を生ぜしめて磁力を利用する構造、検査ユニット１７と船外機本体１１の間を減圧する構造、或いは検査ユニット１７内を減圧する構造などを適宜に採用することが可能である。また、電解質溶液１５ａ，１５ｂは、塩化ナトリウムに限定されるものではなく、導電性の溶液であればどのような溶液であってもよい。また、ハンドリングを良好にするために、電解質溶液１５ａ，１５ｂに増粘剤を加えて粘度を高めるようにしてもよい。さらに、検査ユニット１７の大きさ，形状，及び材質、測定用開口３１と参照極１８との相対的な配置関係も上記に限定されるものではなく、必要に応じて適宜に変更が可能である。また、塩橋若しくは液絡用エレメント３０の電気抵抗が高いために測定値に影響を及ぼす場合や、塩橋若しくは液絡用エレメント３０の両端部の高低差が大きいために検査ユニット１７内の圧力が変化したり、第２の容器１７内の電解質溶液１５ｂ中の電解質の量が変化するなどの場合には、第２のパイプ部材２９の両端に塩化カリウム入り寒天を装填し、第２のパイプ部材２９の内部を電解質溶液１５ｂによって満たすようにしてもよい。その他、塗装を施した金属面に対して外部電源などを用いた電気的な効果を利用して防食を行なう場合も、電気的な防食効果の影響範囲を簡易に測定することができる。
【００３８】
また、既述の実施形態においては、犠牲陽極に流れる電流を測定すると共に、検査対象物の欠陥部の電位も測定するために参照極１８を使用しているが、犠牲陽極に流れる電流だけを測定する場合には参照極１８を設ける必要がなく、第２の容器１７及びこの内部に充填された電解質溶液１５ｂから成る検査ユニット（セル構成体）を用いればよい。
【００３９】
【発明の効果】
請求項１に記載の本発明は、第１の容器に充填された電解質溶液に、検査対象物に電気的に接続された犠牲陽極を浸漬する一方、第１の容器とは別の第２の容器に電解質溶液を充填すると共に、第１の容器内の電解質溶液と第２の容器内の電解質溶液とを塩橋若しくは液絡し、第２の容器及び電解質溶液から構成された検査ユニットを検査対象物の欠陥部に対応配置して犠牲陽極に流れる電流を検出し、この検出電流に基づいて犠牲陽極の評価を行なうようにしたものであるから、船外機本体（防食対象物）などの検査対象物の全体を電解質溶液中に浸漬する必要がなく、またサンプルを切り出すことなく、実際の検査対象物のまま犠牲陽極の効果の評価を簡易に、場所を限定することなく、測定・評価することができる。しかも、その測定・評価にあたっては、他の因子の影響が当該測定値に及ぼす影響は少ないため、塗装を施した金属面を有する船外機本体などのような検査対象物における犠牲陽極の効果を従来の場合よりも短時間でしかも正確に測定・評価することが可能である。また、塩橋若しくは液絡によるセル構造を採用したことにより、立体的な実際の船外機本体に対しても適宜に測定・評価を行なうことができる。
【００４０】
また、請求項２に記載の本発明は、検査ユニットを検査対象物の複数箇所の欠陥部にそれぞれ対応配置し、その際に犠牲陽極にそれぞれ流れる電流の電流値若しくは電流密度に基づいて犠牲陽極の効果が有効な範囲を判定するようにしたものであるから、検査対象物の全体を電解質溶液中に浸漬する必要がなく、またサンプルを切り出すことなく、実際の検査対象物のまま犠牲陽極の影響範囲（効果範囲）を簡易に、場所を限定することなく、測定・評価することができる。しかも、その測定・評価にあたっては、他の因子の影響が当該測定値に及ぼす影響は少ないため、塗装を施した金属面を有する船外機本体などのような検査対象物における犠牲陽極の影響範囲を正確に判定することが可能である。
【００４１】
また、請求項３に記載の本発明は、第１の容器に充填された電解質溶液に、検査対象物に電気的に接続された犠牲陽極を浸漬する一方、第１の容器とは別の第２の容器に電解質溶液を充填すると共に第２の容器内の電解質溶液に参照極を浸漬し、第１の容器内の電解質溶液と第２の容器内の電解質溶液とを塩橋若しくは液絡し、第２の容器，参照極，及び電解質溶液から構成された検査ユニットを検査対象物の欠陥部に対応配置して検査対象物の欠陥部の電位を検出し、この検出電位に基づいて犠牲陽極の評価を行なうようにしたものであるから、請求項１に記載の本発明の場合と同様の作用効果を奏することができる。
【００４２】
また、請求項４に記載の本発明は、検査ユニットを検査対象物の複数箇所の欠陥部にそれぞれ対応配置し、その際の検査対象物の欠陥部の各所における電位に基づいて犠牲陽極の効果が有効な範囲を判定するようにしたものであるから、請求項２に記載の本発明の場合と同様の作用効果を奏することができる。
【００４３】
また、請求項５に記載の本発明は、第１の容器内に充填された電解質溶液の中に犠牲陽極を浸漬して成る第１のセル構成部、第１の容器とは別の第２の容器と、第２の容器内に密封状態で充填された電解質溶液とを有する第２のセル構成部としての検査ユニット、第１の容器内の電解質溶液と第２の容器内の電解質溶液とを相互に塩橋若しくは液絡する電気接続部、犠牲電極に流れる電流を検出する電流検出手段をそれぞれ具備し、検査ユニットを検査対象物の欠陥部に対応配置したときに犠牲陽極に流れる電流を電流検出手段にて検出し、この検出電流に基づいて犠牲陽極を評価するようにしたものであるから、請求項１に記載の本発明に係る犠牲陽極の検査方法を施行し得る実用的な検査装置を提供することができる。
【００４４】
また、請求項６に記載の本発明は、第１の容器内に充填された電解質溶液の中に犠牲陽極を浸漬して成る第１のセル構成部、第１の容器とは別の第２の容器と、第２の容器内に密封状態で充填された電解質溶液と、第２の容器内の電解質溶液に浸漬された参照極とを有する第２のセル構成部としての検査ユニット、第１の容器内の電解質溶液と第２の容器内の電解質溶液とを相互に塩橋若しくは液絡する電気接続部、検査対象物の欠陥部における電位を検出する電位検出手段をそれぞれ具備し、検査ユニットを検査対象物の欠陥部に対応配置したときの検査対象物の欠陥部の電位を電位検出手段にて検出し、この検出電位に基づいて犠牲陽極を評価するようにしたものであるから、請求項３に記載の本発明に係る犠牲陽極の検査方法を施行し得る実用的な検査装置を提供することができる。
【００４５】
また、請求項７に記載の本発明は、参照極に接続されたリード線、及び、検査対象物の欠陥部に接続されたリード線を電位検出手段に接続して検査対象物の欠陥部における電位を計測し、その検出電位に基づいて犠牲陽極の評価を行なうように構成したものであるから、簡素な構成の検査装置にて犠牲陽極の効果及び影響範囲（効果範囲）の測定・評価を行なうことができる。
【００４６】
また、請求項８に記載の本発明は、検査ユニットの第２の容器に、第１及び第２の容器内の電解質溶液を相互に連通するための第１のパイプ部材、並びに、第２の容器の外部からその内部に電解質溶液を導入して第２の容器内の圧力調整，第２の容器のエア抜き，及び第２の容器への電解質溶液の供給制御を行なうための第２のパイプ部材を取付けるようにしたものであるから、第２の容器内の電解質溶液の出し入れを簡易に行なうことができ、電解質溶液の汚染などを防ぐことができ、かつ、測定面以外の部分への電解質溶液の漏れに起因する測定誤差を減少させることができる。
【００４７】
また、請求項９に記載の本発明は、第２の容器内への第１のパイプ部材の挿入長さを短く設定して第１のパイプ部材の一端部を第２の容器の天壁部の近傍位置に配置すると共に、第２の容器内への第２のパイプ部材の挿入長さを第１のパイプ部材の挿入長さよりも長く設定して第２のパイプ部材の一端部を第２の容器の底壁部の近傍位置に配置するようにしたものであるから、第１のパイプ部材にて塩橋或いは液絡を確保することができると共に、第２のパイプ部材により第２の容器内の圧力調整，第２の容器のエア抜き，及び第２の容器への電解質溶液の供給制御を円滑にかつ確実に行なうことができる。
【００４８】
また、請求項１０に記載の本発明は、検査ユニットの第２の容器の底壁部に測定用開口を設け、測定用開口に参照極を対応配置すると共に、測定用開口内に多孔質体を配置して測定用開口を多孔質体にて閉塞するようにしたものであるから、簡単な構成のものでありながら実用に供し得る検査装置を提供することができる。
【００４９】
かくして、上述の如き本発明の検査方法及び検査装置によれば、電流、電位の測定結果から犠牲陽極の効果の分布を把握し、適切に効果を発揮できる犠牲陽極の配置位置，量，及び表面積を簡易に決定することができる。さらに、本発明の検査方法及び検査装置を用いることにより、塩水噴霧試験や複合サイクル試験より遥かに短時間で犠牲陽極の効果及び影響範囲（有効範囲）を測定・評価を行なうことができる。
【図面の簡単な説明】
【図１】本発明に係る犠牲陽極の検査方法を施行するための検査装置の構成図である。
【図２】図１の検査装置を構成する第２のセル構成部の構造を示す断面図である。
【図３】本発明に係る検査装置を１箇所の欠陥部に対応配置して犠牲陽極に流れる電流を計測している状況（本発明の実施例１）を示す図である。
【図４】本発明に係る検査装置を複数箇所の欠陥部にそれぞれ対応配置して犠牲陽極に流れる電流を計測している状況（本発明の実施例２）を示す図である。
【図５】本発明に係る検査装置を１箇所の欠陥部に対応配置して欠陥部の電位を計測している状況を示す図である。
【図６】本発明に係る検査装置を複数箇所の欠陥部にそれぞれ対応配置して欠陥部の電位を計測している状況（本発明の実施例３）を示す図である。
【図７】比較例１における電流検査方法を示す図である。
【図８】比較例２における電流検査方法を示す図である。
【図９】犠牲陽極の設置予定位置からの距離と、各欠陥部に流れる電流の電流密度値との関係（実験結果）をプロットしたグラフである。
【図１０】サンプル素材の金属の自然電位と、犠牲陽極からの距離との関係（実験結果）をプロットしたグラフである。
【図１１】流電陽極からの電流の分布を概略的に示す図である。
【図１２】犠牲陽極の検査方法の一例を示す図である。
【図１３】船外機の外観及び犠牲陽極の取付位置の一例を示す図である。
【図１４】異種（２種類）の金属材料から成る金属平板を電解質溶液の中に浸漬した場合にこれらの間に電流が流れることを説明するための図である。
【図１５】図１５（ａ）は、欠陥部をもつ塗装金属である防食対象物を犠牲陽極に導線を介して相互に接続して電解質溶液の中に浸漬した場合に導線を通って電子が流れることを説明するための図、図１５（ｂ）は図１５（ａ）に示す状態に対応する等価回路である。
【図１６】図１６（ａ）は、欠陥部が１箇所だけに存在する場合であって、かつ、犠牲陽極の設置予定箇所から欠陥部までの距離が短い場合の等価回路、図１６（ｂ）は、欠陥部が１箇所だけに存在する場合であって、犠牲陽極の設置予定箇所から欠陥部までの距離が長い場合の等価回路、図１６（ｃ）は、欠陥部が複数箇所に存在する場合の等価回路である。
【符号の説明】
１０検査装置
１１船外機本体
１２欠陥部
１３第１の容器
１５ａ，１５ｂ電解質溶液
１６犠牲陽極
１７第２の容器
１８参照電極
２０検査ユニット（セル構成体）
２１第１のセル構成部
２２第２のセル構成部
２３電気接続部
２４電流計（電流検出手段）
２５ポテンショスタット（電位検出手段）
２８第１のパイプ部材
２９第２のパイプ部材
３０塩橋若しくは液絡用エメント
３１測定用開口
３２多孔質体
４０，４２リード線
Ｃ金属材料
Ｄ塗装
Ｐ犠牲陽極設置予定位置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inspection method and an inspection apparatus for a sacrificial anode, and more specifically, an evaluation of the sacrificial anode (particularly, an evaluation of an effect on a coated metal surface) and a range in which the effect of the sacrificial anode is effective. The present invention relates to an inspection method and an inspection apparatus.
[0002]
[Prior art]
One method for improving the corrosion resistance of an outboard motor body (an anticorrosion object) on which a propeller is mounted is to install a sacrificial anode on the outboard motor body. Outboard motors are used in harsher environments than ordinary painted metal, so the main body (outboard motor body) should be surface-treated and painted to increase the corrosion resistance of the outboard motor body. ing. In addition to this, the corrosion resistance of the outboard motor body is remarkably improved by exhibiting the effect of the sacrificial anode. Note that the sacrificial anode is more easily dissolved than the material of the outboard motor body, and serves to prevent corrosion of the outboard motor body by dissolving itself and supplying electrons to the outboard motor body side. Is responsible for.
[0003]
[Problems to be solved by the invention]
In evaluating the corrosion resistance of the outboard motor body, salt spray tests, combined cycle tests, erosion corrosion tests (tests in which the parts to be evaluated are immersed in a salt solution) are conducted. Since a treatment for increasing the corrosion resistance of the main body itself is performed, a long test time is required when performing a salt spray test, a combined cycle test, or an erosion corrosion test.
[0004]
In addition, the actual location of the sacrificial anode is often dependent on experience and intuition. The distribution of the current I flowing from the galvanic anode (sacrificial anode) A to the anticorrosion object B is often expressed as shown in FIGS. 11 (a) and 11 (b), and sacrificed based on this distribution and characteristic data. In many cases, the installation position of the anode is selected, but in addition to the distance of the current path from the sacrificial anode to the outboard motor body, the shape of the outboard motor body and sacrificial anode, the material of the outboard motor body, surface treatment, In addition, because of the influence of the type of coating and the film thickness, the effect may not be fully exhibited.
[0005]
On the other hand, as shown in FIG. 12, the reference electrode 101 is immersed in the electrolyte solution 100 and the sacrificial anode 103 and the counter electrode 104 are immersed in the electrolyte solution 102, and the

electrolyte solutions

100 and 102 are salted through the Lugin tube 105. The characteristics of the sacrificial anode 103 can be measured by bridging and measuring the potential with the potentiostat 106. However, in order to perform such an experiment, it is necessary to cut out an inspection object (inspected object) as a test piece. Further, as shown in FIG. 13, when the characteristics of the sacrificial anode 103 are measured by immersing the entire outboard motor main body 107 as an inspection object in an electrolyte solution 108 (seawater, artificial seawater, etc.), measurement is performed. Since many parts other than the target location are also immersed in the electrolyte solution 108, it is not certain whether only the measurement target location is being measured. Furthermore, in order to purely understand the influence of the sacrificial anode 103 on the outboard motor main body 107 side, it is necessary to arrange measurement electrodes close to the outboard motor main body 107. There are many influences from other factors, and proper evaluation of the sacrificial anode 103 is difficult.
[0006]
In addition, rough estimation is possible by using a flat sample and immersing and measuring the entire sample in an electrolyte solution. However, since the actual surface of the outboard motor body 107 includes not only a flat surface but also a complicated curved shape (three-dimensional), and also a shadowed back side portion, the influence of the sacrificial anode 103 is simply calculated. It is difficult to grasp how far and what range is covered with the outboard motor main body 107. In addition, the calculated effect may not match the actual effect.
[0007]
On the other hand, Japanese Patent Application Laid-Open No. 7-208910 discloses a method and apparatus for measuring the surface area of a galvanic electrode in order to measure the remaining life of the galvanic electrode. This method and apparatus is disclosed in the present invention. This is different from the method and apparatus for determining the installation position and amount of the sacrificial anode itself.
[0008]
The present invention has been made in view of the above circumstances, and its purpose is to influence the sacrificial anode on the actual outboard motor body.
It is an object of the present invention to provide a sacrificial anode inspection method and inspection apparatus capable of accurately evaluating in a short time without immersing the entire outboard motor body to which the sacrificial anode is attached.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, in the sacrificial anode inspection method according to the present invention, the sacrificial anode electrically connected to the object to be inspected is immersed in the electrolyte solution filled in the first container. A second container different from the first container is filled with the electrolyte solution, and the electrolyte solution in the first container and the electrolyte solution in the second container are salt-bridged or liquid-tangled, An inspection unit composed of the container 2 and the electrolyte solution is arranged corresponding to the defect portion of the inspection object to detect a current flowing through the sacrificial anode, and the sacrificial anode is evaluated based on the detected current. Yes.
In the sacrificial anode inspection method according to the present invention, the inspection unit is arranged corresponding to each of the plurality of defective portions of the inspection object, and at that time, the current value or current density of the current flowing through the sacrificial anode is set. Based on this, the effective range of the sacrificial anode is determined.
In the method for inspecting a sacrificial anode according to the present invention, the sacrificial anode electrically connected to the object to be inspected is immersed in the electrolyte solution filled in the first container, but separately from the first container. And filling the electrolyte solution in the second container and immersing the reference electrode in the electrolyte solution in the second container to salt the electrolyte solution in the first container and the electrolyte solution in the second container. An inspection unit constituted by a bridge or a liquid junction and configured by the second container, the reference electrode, and the electrolyte solution is arranged corresponding to the defect portion of the inspection object to detect the potential of the defect portion of the inspection object, The sacrificial anode is evaluated based on the detection potential.
Further, in the sacrificial anode inspection method according to the present invention, the inspection unit is arranged corresponding to each of the plurality of defective portions of the inspection object, and based on the potential at each of the defective portions of the inspection object at that time The effective range of the sacrificial anode is determined.
In the sacrificial anode inspection apparatus according to the present invention,
(A) a first cell component formed by immersing a sacrificial anode in an electrolyte solution filled in a first container;
(B) a test unit as a second cell component having a second container different from the first container and an electrolyte solution filled in a sealed state in the second container;
(C) an electrical connection part that mutually salt bridges or liquids the electrolyte solution in the first container and the electrolyte solution in the second container;
(D) current detection means for detecting a current flowing through the sacrificial electrode;
Each with
A current flowing through the sacrificial anode is detected by the current detecting means when the inspection unit is arranged corresponding to a defective portion of the inspection object, and the sacrificial anode is evaluated based on the detected current.
In the sacrificial anode inspection apparatus according to the present invention,
(A) a first cell component formed by immersing a sacrificial anode in an electrolyte solution filled in a first container;
(B) a second container different from the first container, an electrolyte solution filled in a sealed state in the second container, and a reference electrode immersed in the electrolyte solution in the second container An inspection unit as a second cell component having
(C) an electrical connection part that mutually salt bridges or liquids the electrolyte solution in the first container and the electrolyte solution in the second container;
(D) a potential detecting means for detecting a potential at a defective portion of the inspection object;
Each with
The potential detection means detects the potential of the defect portion of the inspection object when the inspection unit is arranged corresponding to the defect portion of the inspection object, and the sacrificial anode is evaluated based on the detected potential. Yes.
Further, in the sacrificial anode inspection apparatus according to the present invention, the lead wire connected to the reference electrode and the lead wire connected to the defective portion of the inspection object are connected to the potential detection means to the inspection object. The potential at the defect portion of the object is measured, and the sacrificial anode is evaluated based on the detected potential.
In the sacrificial anode inspection apparatus according to the present invention, the first pipe member for communicating the electrolyte solution in the first and second containers with the second container of the inspection unit, and An electrolyte solution is introduced into the second container from the outside to adjust the pressure in the second container, bleed the second container, and supply control of the electrolyte solution to the second container A second pipe member for performing the above is attached.
In the sacrificial anode inspection apparatus according to the present invention, the insertion length of the first pipe member into the second container is set to be short, and one end of the first pipe member is connected to the second pipe. The second pipe member is disposed at a position near the top wall of the container, and an insertion length of the second pipe member into the second container is set longer than an insertion length of the first pipe member. One end of the pipe member is disposed in the vicinity of the bottom wall of the second container.
In the sacrificial anode inspection apparatus according to the present invention, a measurement opening is provided in a bottom wall portion of the second container of the inspection unit, the reference electrode is disposed in correspondence with the measurement opening, and the measurement opening is provided. A porous body is disposed in the inside, and the measurement opening is closed with the porous body.
[0010]
Here, before describing embodiments of the present invention, the principle of the present invention will be briefly described as follows. First, as shown in FIG. 14 (a), when

metal plates

1 and 2 made of different kinds (two types) of metal materials are immersed in an electrolyte solution 3 such as a potassium chloride solution and both are connected by a conductive wire 4, Relative ionization tendency (permutation of activity of metals / alloys in electrolyte solution) through lead 4 from metal plate 1 made of a relatively large metal material of ionization tendency (permutation of activity of metals / alloys in electrolyte solution) Electron e is applied to a flat metal plate 2 made of a small metal material. ^- Is supplied. At this time, the metal flat plate 1 serves as an anode (anode), the metal flat plate 2 serves as a cathode (cathode), and the metal flat plate 1 functions as a sacrificial anode with respect to the metal flat plate 2. Even if the electrolyte solution 3 is separated into the electrolyte solution 3a for the metal flat plate 1 and the electrolyte solution 3b for the metal flat plate 2 as shown in FIG. 14B, these

electrolyte solutions

3a and 3b are separated. If they are connected to each other by the salt bridge or the liquid junction element 5, the same result as above can be obtained.
[0011]
In addition, as shown in FIG. 15A, when the corrosion protection object 7, which is a painted metal having a defective portion 6, is connected to the sacrificial anode 8 through the conductor 9 and immersed in the electrolyte solution 3. , Electrons flow through the conductive wire 9 as the sacrificial anode 8 is dissolved. Then, the current I at this time has a distribution as indicated by a broken-line arrow in FIG. 15A, and flows in a concentrated manner in the defect portion 6 present in the anticorrosion object 7. At this time, it can be considered that a circuit as shown in FIG. In this case, the sacrificial electrode 8 as the anode electrode is regarded as a battery as a potential generation source, and is indicated by a battery E in the circuit of FIG.
[0012]
Here, r represents the resistance of the metal material C constituting the anticorrosion object 7, r ′ represents the resistance (coating resistance) of the coating D of the anticorrosion object 7, r ″ represents the resistance of the electrolyte solution 3, and R represents the total resistance. Then, the entire current I can be expressed by the following formula (1).
I = E / (r + r ′ + r ″) (1)
[0013]
Similarly, when the defect portion 6 exists only in one place and the distance from the planned installation position P of the sacrificial anode 8 to the defective portion 6 is short (the planned installation position P of the sacrificial anode 8 and the defective portion). 16), the circuit can be represented by a circuit as shown in FIG. 16A, and the distance from the planned installation position P of the sacrificial anode 8 to the defective portion 6 is long (installation of the sacrificial anode 8). When the planned position P and the defect portion 6 are far from each other), it can be expressed by a circuit as shown in FIG. Note that the resistance r ′ of the coating D is a constant value if the coating of the anticorrosion object 7 is uniform, and the resistance r of the metal material C constituting the anticorrosion object 7 and the resistance r ″ of the electrolyte solution 3 are The longer the distance, the larger.
[0014]
Total resistance R in the case where the planned installation position P of the sacrificial anode 8 and the defective portion 6 are close to each other. _a In this case, the resistance r is r _a Then, it is represented by the following formula (2).
R _a = R _a + R '+ r _a '' ……… (2)
Further, the total resistance R in the case where the planned installation position P of the sacrificial anode 8 and the defect portion 6 are far from each other. _b In this case, the resistance r is r _b Then, it is represented by the following formula (3).
R _b = R _b + R '+ r _b '' ……… (3)
Therefore, the current I flowing in the defective portion 6 at that time _a , I _b Are represented by the following equations (4) and (5), respectively.
I _a = E / R _a ……… (4)
I _b = E / R _b ……… (5)
[0015]
Moreover, when the defect part 6 exists in multiple places, it can represent with a circuit as shown in FIG.16 (c). Total resistance R at this time _c Is given by equation (6) below.
R _c = {(R _a + R '+ r _a '') X (r _b + R '+ r _b '')} / {(R _a + R '+ r _a '') + (R _b + R '+ r _b '')} ……… (6)
And current I at that time _c Is represented by the following formula (7).
I _c = E / R _c ……… (7)
Therefore, the sacrificial anode 8 is measured so that the current value I flowing in each location where the defect portion 6 is present is measured and the current value necessary for anticorrosion is not reduced based on these measured values, and the overcorrosion is not caused. The position, amount, and surface area of the sacrificial anode 8 that can sufficiently exhibit the effect can be determined.
[0016]
These are electrochemical measurements, and the current value and voltage value can be measured in a short time. Based on the current value or voltage value (potential value), salt water used as a conventional evaluation method The sacrificial electrode 8 can be evaluated in a much shorter time than a spray test or a combined cycle test (for example, an evaluation time of about 1000 hours is required).
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0018]
1 and 2 show an inspection device (cell device) 10 for carrying out the method for inspecting a sacrificial anode according to the present invention. This inspection device 10 is a defective portion 12 of an outboard motor main body 11. It is an apparatus for measuring and evaluating the effect of the sacrificial anode and the range of influence (effective range). As shown in FIG. 1, the inspection apparatus 10 of the present embodiment is electrically connected to an electrolyte solution (for example, sodium chloride solution) 15 a filled in a first container 13 by a lead wire 14 on an outboard motor main body 11. While sacrificing the sacrificial anode 16 connected to the first container 13, the second container 17 different from the first container 13 is filled with the electrolyte solution (for example, sodium chloride solution) 15b and the electrolyte solution in the second container 17 The reference electrode 18 is immersed in 15b, and the electrolyte solution 15a in the first container 13 and the electrolyte solution 15b in the second container 17 are formed by salt bridge or liquid junction, and the second container 17, An inspection unit (cell structure) 20 composed of the reference electrode 18 and the electrolyte solution 15b is arranged corresponding to the defective portion 12 of the outboard motor main body 11 which is an inspection object, and the current Sacrifice based on potential It is obtained as polar performed 16 Evaluation of the.
[0019]
More specifically, the above-described inspection apparatus 10 includes a first cell component 21, a first container formed by immersing the sacrificial anode 16 in an electrolyte solution 15 a filled in the first container 13. A second container 17 different from 13, an electrolyte solution 15 b filled in a sealed state in the second container, and a reference electrode 18 immersed in the electrolyte solution 15 b in the second container 17 The unit is composed of a second cell component 22 as a unit, and an electrical connection 23 for salt electrolyte bridge or liquid junction between the electrolyte solution 15a in the first container 13 and the electrolyte solution 15b in the second container 17. In order to detect the current flowing through the sacrificial electrode 16, an ammeter 24 is provided as current detecting means provided on the lead wire 14 as shown in FIGS. Further, a potentiostat 25 as a potential detecting means is attached. In the case shown in FIG. 5, the potentiostat 25 is connected to the lead wire 40 connected to the reference electrode 18 and the defective portion 12 of the outboard motor main body 11. Lead wires 42 are connected to the potentiostat 25, respectively. On the other hand, in the case shown in FIG. 6, the lead wire 40 connected to the reference electrode 18 is connected to the potentiostat 25 and a plurality of lead wires respectively connected to the plurality of defective portions 12 of the outboard motor main body 11. 42 is connected to the potentiostat 25 via a switch 62.
[0020]
Further, as clearly shown in FIG. 2, the second container 17 of the above-described second cell constituent unit 22 includes a cylindrical frame body 26 having openings at the upper part and the lower part thereof, an upper part of the frame body 26, and It is a sealed container composed of

silicon stoppers

27a and 27b fitted respectively to the lower part, and the inside thereof is filled with the electrolyte solution 15b in a completely sealed state. The reference electrode 18 described above penetrates the silicon plug 27a (the top wall portion of the second container 17) and is immersed in the electrolyte solution 15b in the second container 17. Furthermore, the above-described silicon stopper 27a includes a first pipe member 28 for electrically connecting the

electrolyte solutions

15a and 15b in the first and

second containers

13 and 17 to each other, and a second container. A second electrolyte solution 15b is introduced from the outside of the container 13 into the second container 17 to adjust the pressure in the second container 17 and supply of the electrolyte solution 15b, and to release the air in the second container 17. A pipe member 29 is attached in a penetrating state. That is, the first and

second pipe members

28 and 29 made of, for example, Teflon (registered trademark) are disposed through the silicon plug 27a constituting the top wall portion of the second container 17, and the first pipe One end portion of the member 28 is immersed in the electrolyte solution 15b near the silicon plug 27a, and one end portion of the second pipe member 29 is opposed to the silicon plug 27a (the bottom wall of the second container 17). Part). Therefore, the immersion length of the two types of

pipe members

28 and 29 in the electrolyte solution 15b in the second container 27 is the same as that of the first pipe member 28, the silicon plug 27a (the top wall) of the second container 17. The second pipe member 29 is set to be longer than the insertion length of the first pipe member 28, and one end portion thereof is set to be longer than the insertion length of the first pipe member 28. It is arranged in the vicinity of the silicon stopper 27b of the second container 17 serving as the end portion on the cell measurement surface side.
[0021]
Then, one end of a salt bridge or a liquid junction element 30 is connected to the other end of the first pipe member 28 disposed outside the second container 17. As this salt bridge or liquid junction element 30, for example, a tube in which agar containing potassium chloride is hardened is used in a tube and is adjusted so as to always show the same resistance value. On the other hand, the other end of the salt bridge or liquid junction element 30 is fixed in a state of being immersed in the electrolyte solution 15a in the first container 13 described above.
[0022]
Further, a measurement opening 31 is formed at a substantially central position in the silicon plug 27 b (cell measurement surface bottom wall portion) of the second container 17, and the porous body 32 having continuous pores is formed in the measurement opening 31. Is placed in the insert. Then, the pressure inside the second container 17 is adjusted by the syringe 33 provided on the second pipe member 29 outside the second container 17 and the supply of the electrolyte solution 15b to the measurement opening 31 is controlled. By doing so, the electrolyte solution 15b is prevented from leaking to areas other than the measurement-corresponding surface α (see FIGS. 1 and 2). On the other hand, the tip of the above-described reference electrode 18 is disposed at a position immediately above the measurement opening 31, and the distance from the opening measurement opening 31, that is, the silicon stopper on the bottom side of the second container 17. The distance from the measurement corresponding surface α of 27b is set to a minimum. Incidentally, the measurement opening 31 is arranged at the center position of the measurement-corresponding surface α and has an area of about 1 cm so as to cope with the case where the surface of the inspection object is a curved surface. ² The entire area is closed by the porous body 32, and leakage of the electrolyte solution 15b in the second container 17 is prevented. The thickness of the porous body 32 is such that the distance between the reference electrode 18 and the measurement corresponding surface α can be minimized while the electrolyte solution 15b is securely held without passing (preferably, 1 mm to 15 mm).
[0023]
As shown in FIGS. 1 and 2, O-

rings

34 and 35 are disposed on the measurement-corresponding surface α of the second container 17 in order to prevent the electrolyte solution 15 b from coming into contact with portions other than the measurement opening 31. Thus, the measurement corresponding surface α can be brought into close contact with the measurement surface of the inspection object. The portion corresponding to the measurement-corresponding surface is made of a member that can seal the frame 26 and a member such as a silicon plug 27b made of a material that does not damage the measurement surface of the inspection object.
[0024]
Next, the procedure for inspecting (evaluating) the sacrificial anode 16 of the outboard motor body 11 using the above-described inspection apparatus 10 will be described as follows. First, the outboard motor main body 11 that is an anticorrosion object is installed in the same manner as in use, and one end of the lead wire 14 is connected to the sacrificial anode installation planned position P as shown in FIGS. Then, the other end of the lead wire 14 is connected to the sacrificial anode 16, and the sacrificial anode 16 is immersed in the electrolyte solution 15 a in the first container 13 in a state where the lead wire 14 is not immersed. On the other hand, as shown in FIG. 3 or FIG. 4, an artificial defect portion (defect portion) 12 is formed in one or a plurality of locations of the outboard motor main body 11 that is an anticorrosion target by a technique such as cross-cutting. To do. Next, the inspection unit 20 which is the second cell constituent unit 22 is moved so that the measurement corresponding surface α of the inspection unit 20 is arranged on the surface of the outboard motor main body 11 via the O-

rings

34 and 35 and is used for measurement. It installs in the state which covered the defect part 12 with the opening 31 (refer FIG.3 and FIG.4). At this time, the outboard motor main body 11 and the sacrificial anode 16 are mutually connected via a salt bridge or a liquid junction element 30 that connects the

electrolyte solutions

15a and 15b in the first and

second containers

13 and 17. Set to the state of being electrically connected to.
[0025]
Next, under this state, the current value / current density of the current flowing through the lead wire 14, that is, the current flowing through the sacrificial anode 16 is detected (measured) by the ammeter 24. Thus, by appropriately changing the position of the defective portion 12, the effect of the sacrificial anode 16 at each position (a plurality of locations separated from the sacrificial anode 16) by the current value / current It can be expressed in density. That is, the surface area and amount of the sacrificial anode 16 and the distance from the sacrificial anode installation planned position P to the defective portion 12 are appropriately changed, and the current in the outboard motor body 11 can be easily changed from the current value and current density at this time. It is possible to grasp the degree. Therefore, when the current density exceeds the current density necessary for the calculation of corrosion protection, it can be seen that the effect of the sacrificial anode 16 has reached the portion (location), and the current density is calculated. When the current density is lower than that required for corrosion protection, it can be seen that the effect of the sacrificial anode 16 does not reach that portion (location). Therefore, the effective range of the sacrificial anode can be determined, and the size, amount, and surface area of the sacrificial anode 16 can be examined, or the installation position of the sacrificial anode 16 can be examined. It is.
[0026]
5 and 6 show an embodiment in which the potential at the defect portion 12 is also measured. In the case of a sample having one defective portion 12 as shown in FIG. 5, the lead wire 42 is connected to the defective portion 12 while the connection to the sacrificial anode 16 is continued as in the above case. The wire 42 and the lead wire 40 of the reference electrode 18 are connected to the potentiostat 25. Further, in the case of a sample having a plurality of defect portions 12 as shown in FIG. 6, the lead wires 42 are respectively connected to the defect portions 12 while the connection with the sacrificial anode 16 is continued as in the above case. These lead wires 42 and the lead wire 40 of the reference electrode 18 are connected to the potentiostat 25 via the switch 62. In this way, the potential at each part of the defect portion 12 can be measured by the potentiostat 25, and the sacrificial anode can be evaluated based on the measured potential.
[0027]
Next, examples and comparative examples of the present invention will be described as follows. In the embodiment of the present invention, 3% sodium chloride aqueous solution is used as the

electrolyte solutions

15a and 15b, and the area of the sacrificial anode 16 is 1 cm. ² It was. As the sample, an aluminum die-cast material coated was used, and measurement was performed at 5 cm, 10 cm, 15 cm, and 20 cm from the actual distance from the sacrificial anode installation planned position P to the defect portion 12. The length of the salt bridge or liquid junction element 30 was set to the spatial distance to the defect portion 12.
[0028]
Details of each example are shown in Table 1 below.
[Table 1]

[0029]
Table 2 below shows the relationship (experimental results) between the distance from the sacrificial anode installation planned position P to the defect portion 12 and the current density value of the current flowing through each defect portion 12.
[Table 2]

[0030]
FIG. 9 is a graph plotting the experimental results in Table 2 above. The horizontal axis of the graph of FIG. 9 is the distance from the sacrificial anode 16, and the vertical axis is the current density ratio when the current density required for corrosion protection is 1.
[0031]
In Example 1 and Comparative Example 1, measurement was performed on a sample assuming a case where the defect portion 12 exists only in one place. In the cell method of Example 1 and the immersion method of Comparative Example 1, both showed the same level of current value and current density value, and the values became smaller as the distance from the sacrificial anode 16 became longer. This indicates that the effect of the sacrificial anode 16 gradually decreases in proportion to the increase in distance.
[0032]
Moreover, Example 2 and Comparative Example 2 were measured on samples that assumed a case where the defect portion 12 was present at a plurality of locations. The cell method of Example 2 and the immersion method of Comparative Example 2 both show the same level of current value / current density value, and the decreasing tendency of the effect of the sacrificial anode 16 with the increase in distance is the same regardless of the method. there were. This also showed that the effect of the sacrificial anode decreased in proportion to the increase in distance.
[0033]
When the defect portion 12 is present at a plurality of locations, current is supplied from a nearby location, and therefore lower than that under the same distance condition as measured when the defect portion 12 exists at only one location. The current density ratio is shown. If the current density is small, the effect of anticorrosion is low, and if it is too large, the anticorrosion is excessive. Therefore, considering the balance between the two, the installation position of the sacrificial anode 16 can be easily determined by the cell system of the present invention.
[0034]
The measurement results of the potential in the case of Example 3 are shown in Table 3 below.
[Table 3]

[0035]
FIG. 10 is a graph plotting the experimental results of Table 3 above. The vertical axis of the graph of FIG. 10 is the natural potential of the sample material metal, and the horizontal axis is the distance from the sacrificial anode 16. The potential required for corrosion prevention of each defective portion 12 is required to be about 0.2 V to 0.3 V lower than the natural potential of the metal constituting the corrosion prevention object (outboard motor main body 11). In the sample of Example 3, a range M indicated by a large number of dots in the graph of FIG. 10 is an expected potential range. From the measurement results, it was confirmed that the sacrificial anode 16 maintained a sufficient potential for corrosion protection of the sample even when the distance was increased. In addition, although the change in potential with distance was small, it could be read by the cell method.
[0036]
From the above, it was found that by using the cell system of the present invention, measurement equivalent to the immersion system can be performed more easily, and the expected effect (effectiveness of the cell system) of the present invention was confirmed.
[0037]
Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and various modifications and changes can be made based on the technical idea of the present invention. For example, the structure for arranging the measurement opening 31 of the inspection unit 17 (second cell component 22) in close contact with the defective portion 12 of the outboard motor main body 11 is the porous body 32 as described above. The structure is not limited to the structure using the inspection unit 17, the structure in which the inspection unit 17 is installed in the outboard motor main body 11 with a clamp, the magnet is embedded in the bottom surface of the inspection unit 17, and the magnetic field is also generated on the outboard motor main body 11 side. It is possible to appropriately employ a structure that uses magnetic force, a structure that reduces the pressure between the inspection unit 17 and the outboard motor main body 11, a structure that reduces the pressure inside the inspection unit 17, and the like. Moreover, the

electrolyte solutions

15a and 15b are not limited to sodium chloride, and any solution may be used as long as it is a conductive solution. In order to improve handling, a thickener may be added to the

electrolyte solutions

15a and 15b to increase the viscosity. Further, the size, shape, and material of the inspection unit 17 and the relative positional relationship between the measurement opening 31 and the reference electrode 18 are not limited to the above, and can be appropriately changed as necessary. . Further, when the electric resistance of the salt bridge or the liquid junction element 30 is high, the measurement value is affected, or because the height difference between both ends of the salt bridge or the liquid junction element 30 is large, the pressure in the inspection unit 17 is increased. Or the amount of the electrolyte in the electrolyte solution 15b in the second container 17 changes, the agar containing potassium chloride is loaded on both ends of the second pipe member 29, and the second pipe The inside of the member 29 may be filled with the electrolyte solution 15b. In addition, in the case where corrosion protection is performed on a coated metal surface using an electrical effect using an external power source or the like, the influence range of the electrical corrosion protection effect can be easily measured.
[0038]
In the embodiment described above, the reference electrode 18 is used to measure the current flowing through the sacrificial anode and also measure the potential of the defective portion of the inspection object. However, only the current flowing through the sacrificial anode is used. In the case of measurement, it is not necessary to provide the reference electrode 18, and an inspection unit (cell structure) composed of the second container 17 and the electrolyte solution 15b filled therein may be used.
[0039]
【The invention's effect】
According to the first aspect of the present invention, the sacrificial anode electrically connected to the test object is immersed in the electrolyte solution filled in the first container, while the second container is separate from the first container. The container is filled with the electrolyte solution, and the electrolyte solution in the first container and the electrolyte solution in the second container are salt-bridged or liquid-coupled to inspect the inspection unit composed of the second container and the electrolyte solution. Since the current flowing through the sacrificial anode is detected corresponding to the defective portion of the object and the sacrificial anode is evaluated based on the detected current, the outboard motor body (corrosion protection object), etc. It is not necessary to immerse the entire inspection object in the electrolyte solution, and it is possible to easily evaluate the effect of the sacrificial anode as it is with the actual inspection object without cutting the sample. can do. Moreover, in the measurement and evaluation, since the influence of other factors has little effect on the measured value, the effect of the sacrificial anode on the inspection object such as an outboard motor body having a painted metal surface is not effective. It is possible to measure and evaluate accurately in a shorter time than in the conventional case. Further, by adopting a cell structure with salt bridge or liquid junction, it is possible to appropriately measure and evaluate a three-dimensional actual outboard motor body.
[0040]
Further, according to the present invention, the inspection unit is arranged corresponding to each of the defect portions of the inspection object, and the sacrificial anode is based on the current value or current density of the current flowing through the sacrificial anode at that time. Therefore, it is not necessary to immerse the entire test object in the electrolyte solution, and without cutting out the sample, the sacrificial anode is left as it is. The influence range (effect range) can be easily measured and evaluated without limiting the location. In addition, in the measurement and evaluation, the influence of other factors has little effect on the measured value, so the range of influence of the sacrificial anode on the inspection object such as an outboard motor body with a painted metal surface. Can be accurately determined.
[0041]
According to the third aspect of the present invention, the sacrificial anode electrically connected to the test object is immersed in the electrolyte solution filled in the first container, while the first container different from the first container is used. The container 2 is filled with the electrolyte solution, and the reference electrode is immersed in the electrolyte solution in the second container, and the electrolyte solution in the first container and the electrolyte solution in the second container are salt-bridged or entangled. An inspection unit composed of the second container, the reference electrode, and the electrolyte solution is arranged corresponding to the defect portion of the inspection object to detect the potential of the defect portion of the inspection object, and the sacrificial anode is based on the detected potential. Therefore, the same effects as those of the first aspect of the present invention can be achieved.
[0042]
Further, according to the present invention, the inspection unit is arranged corresponding to each of the plurality of defect portions of the inspection object, and the effect of the sacrificial anode based on the potential at each of the defect portions of the inspection object at that time. Since the effective range is determined, the same operational effects as those of the second aspect of the present invention can be achieved.
[0043]
According to a fifth aspect of the present invention, there is provided a first cell component formed by immersing a sacrificial anode in an electrolyte solution filled in the first container, a second cell separate from the first container. And a test unit as a second cell component having an electrolyte solution filled in a sealed state in the second container, an electrolyte solution in the first container, and an electrolyte solution in the second container Current detecting means for detecting the current flowing through the sacrificial electrode and the electrical connection part that is mutually salt-bridged or liquid junction, and the current flowing through the sacrificial anode when the inspection unit is arranged corresponding to the defective part of the inspection object. Since the sacrificial anode is detected on the basis of the detected current detected by the current detecting means, a practical inspection capable of implementing the sacrificial anode inspection method according to the present invention according to claim 1 An apparatus can be provided.
[0044]
According to a sixth aspect of the present invention, there is provided a first cell component formed by immersing a sacrificial anode in an electrolyte solution filled in the first container, a second cell separate from the first container. A test unit serving as a second cell component, comprising: a container in the second container; an electrolyte solution filled in a sealed state in the second container; and a reference electrode immersed in the electrolyte solution in the second container; An inspection unit comprising an electrical connection portion for salt-bridge or liquid junction between the electrolyte solution in the container and the electrolyte solution in the second container, and potential detection means for detecting the potential at the defective portion of the inspection object. Since the potential detection means detects the potential of the defect portion of the inspection object when the is disposed corresponding to the defect portion of the inspection object, the sacrificial anode is evaluated based on the detected potential. The inspection method of the sacrificial anode according to the present invention described in Item 3 is It is possible to provide a practical test apparatus that.
[0045]
According to the seventh aspect of the present invention, the lead wire connected to the reference electrode and the lead wire connected to the defective portion of the inspection object are connected to the potential detection means to detect the defect in the inspection object. Since it is configured to measure the potential and evaluate the sacrificial anode based on the detected potential, the measurement and evaluation of the effect and the influence range (effect range) of the sacrificial anode can be performed with a simple configuration inspection device. Can be done.
[0046]
Further, according to the present invention, the first pipe member for communicating the electrolyte solution in the first and second containers with each other to the second container of the inspection unit, and the second container A second pipe for introducing an electrolyte solution into the inside of the container from the outside of the container to adjust the pressure in the second container, vent the second container, and control the supply of the electrolyte solution to the second container Since the member is attached, the electrolyte solution in the second container can be easily taken in and out, the electrolyte solution can be prevented from being contaminated, and the electrolyte to the part other than the measurement surface Measurement errors due to solution leakage can be reduced.
[0047]
According to the ninth aspect of the present invention, the insertion length of the first pipe member into the second container is set to be short so that one end of the first pipe member is connected to the top wall of the second container. And the insertion length of the second pipe member into the second container is set to be longer than the insertion length of the first pipe member, and one end of the second pipe member is set to the second position. Since the first pipe member can secure a salt bridge or a liquid junction, the second pipe member can secure the second container. It is possible to smoothly and reliably perform the pressure adjustment in the inside, the air venting of the second container, and the supply control of the electrolyte solution to the second container.
[0048]
According to a tenth aspect of the present invention, a measurement opening is provided in the bottom wall portion of the second container of the inspection unit, a reference electrode is disposed corresponding to the measurement opening, and a porous body is provided in the measurement opening. Since the measurement opening is closed with a porous body, an inspection apparatus that can be used practically can be provided with a simple configuration.
[0049]
Thus, according to the inspection method and inspection apparatus of the present invention as described above, the distribution position, amount, and surface area of the sacrificial anode, which can grasp the distribution of the effect of the sacrificial anode from the measurement results of the current and potential, and can appropriately exert the effect. Can be easily determined. Furthermore, by using the inspection method and inspection apparatus of the present invention, the effect and the influence range (effective range) of the sacrificial anode can be measured and evaluated in a much shorter time than the salt spray test and the combined cycle test.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an inspection apparatus for performing a sacrificial anode inspection method according to the present invention.
FIG. 2 is a cross-sectional view showing a structure of a second cell constituent part constituting the inspection apparatus of FIG. 1;
FIG. 3 is a diagram showing a situation (Embodiment 1 of the present invention) in which an inspection apparatus according to the present invention is arranged corresponding to one defective portion and a current flowing through a sacrificial anode is measured.
FIG. 4 is a diagram showing a situation (Embodiment 2 of the present invention) in which an inspection apparatus according to the present invention is arranged corresponding to each of a plurality of defective portions and current flowing through a sacrificial anode is measured.
FIG. 5 is a diagram showing a situation in which the inspection apparatus according to the present invention is arranged corresponding to one defective portion and the potential of the defective portion is measured.
FIG. 6 is a diagram showing a situation (Embodiment 3 of the present invention) in which the inspection apparatus according to the present invention is arranged corresponding to each of a plurality of defective portions and the potential of the defective portion is measured.
7 is a diagram showing a current inspection method in Comparative Example 1. FIG.
8 is a diagram showing a current inspection method in Comparative Example 2. FIG.
FIG. 9 is a graph plotting the relationship (experimental result) between the distance from the planned installation position of the sacrificial anode and the current density value of the current flowing through each defective portion.
FIG. 10 is a graph plotting the relationship (experimental result) between the natural potential of the sample material metal and the distance from the sacrificial anode.
FIG. 11 is a diagram schematically showing the distribution of current from the galvanic anode.
FIG. 12 is a diagram showing an example of a method for inspecting a sacrificial anode.
FIG. 13 is a diagram showing an example of the appearance of the outboard motor and the attachment position of the sacrificial anode.
FIG. 14 is a diagram for explaining that a current flows between metal plates made of different kinds (two types) of metal materials when immersed in an electrolyte solution.
FIG. 15 (a) shows a case where an anticorrosion object, which is a painted metal having a defective part, is connected to a sacrificial anode via a lead wire and immersed in an electrolyte solution, and electrons pass through the lead wire. FIG. 15B is a diagram for explaining the flow, and FIG. 15B is an equivalent circuit corresponding to the state shown in FIG.
FIG. 16A is an equivalent circuit in the case where there is only one defective portion and the distance from the planned location of the sacrificial anode to the defective portion is short, FIG. ) Is an equivalent circuit in the case where the defect portion exists only in one place, and the distance from the place where the sacrificial anode is scheduled to be installed to the defect portion is long, and FIG. This is an equivalent circuit.
[Explanation of symbols]
10 Inspection equipment
11 Outboard motor body
12 Defects
13 First container
15a, 15b Electrolyte solution
16 Sacrificial anode
17 Second container
18 Reference electrode
20 Inspection unit (cell structure)
21 First cell component
22 Second cell component
23 Electrical connections
24 Ammeter (Current detection means)
25 Potentiostat (potential detection means)
28 First pipe member
29 Second pipe member
30 salt bridge or liquid junction element
31 Measurement aperture
32 Porous material
40, 42 Lead wire
C Metal material
D painting
P Sacrificial anode installation planned position

Claims

While immersing the sacrificial anode electrically connected to the test object in the electrolyte solution filled in the first container, while filling the electrolyte solution in a second container different from the first container, The electrolyte solution in the first container and the electrolyte solution in the second container are salt-bridged or in a liquid junction, and an inspection unit composed of the second container and the electrolyte solution is used as a defect portion of the inspection object. A method for inspecting a sacrificial anode, wherein the sacrificial anode is detected in accordance with a corresponding arrangement and the sacrificial anode is evaluated based on the detected current.

The inspection unit is disposed corresponding to a plurality of defective portions of the inspection object, and the effective range of the sacrificial anode is determined based on the current value or current density of the current flowing through the sacrificial anode at that time. The method for inspecting a sacrificial anode according to claim 1, wherein:

The sacrificial anode electrically connected to the test object is immersed in the electrolyte solution filled in the first container, while the electrolyte solution is filled in the second container different from the first container and A reference electrode is immersed in the electrolyte solution in the second container, and the electrolyte solution in the first container and the electrolyte solution in the second container are salt-bridged or liquid junctioned, and the second container, reference An inspection unit composed of an electrode and an electrolyte solution is arranged corresponding to the defect portion of the inspection object to detect the potential of the defect portion of the inspection object, and the sacrificial anode is evaluated based on the detected potential A method for inspecting a sacrificial anode, characterized in that

The inspection unit is arranged corresponding to each of a plurality of defect portions of the inspection object, and a range in which the effect of the sacrificial anode is effective is determined based on the potential at each of the defect portions of the inspection object at that time. 4. The method for inspecting a sacrificial anode according to claim 3, wherein

(A) a first cell component formed by immersing a sacrificial anode in an electrolyte solution filled in a first container;
(B) a test unit as a second cell component having a second container different from the first container and an electrolyte solution filled in a sealed state in the second container;
(C) an electrical connection part that mutually salt bridges or liquids the electrolyte solution in the first container and the electrolyte solution in the second container;
(D) current detection means for detecting a current flowing through the sacrificial electrode;
Each with
A sacrificial characterized in that when the inspection unit is arranged corresponding to a defective portion of an inspection object, a current flowing through the sacrificial anode is detected by the current detecting means, and the sacrificial anode is evaluated based on the detected current. Anode inspection device.

(A) a first cell component formed by immersing a sacrificial anode in an electrolyte solution filled in a first container;
(B) a second container different from the first container, an electrolyte solution filled in a sealed state in the second container, and a reference electrode immersed in the electrolyte solution in the second container An inspection unit as a second cell component having
(C) an electrical connection part that mutually salt bridges or liquids the electrolyte solution in the first container and the electrolyte solution in the second container;
(D) a potential detecting means for detecting a potential at a defective portion of the inspection object;
Each with
A potential of the defect portion of the inspection object when the inspection unit is arranged corresponding to the defect portion of the inspection object is detected by the potential detection means, and the sacrificial anode is evaluated based on the detected potential. Sacrificial anode inspection equipment.

The lead wire connected to the reference electrode and the lead wire connected to the defect portion of the inspection object are connected to the potential detection means to measure the potential at the defect portion of the inspection object, and the detected potential The sacrificial anode inspection apparatus according to claim 6, wherein the sacrificial anode is evaluated based on the evaluation.

A first pipe member for communicating the electrolyte solution in the first and second containers with each other to the second container of the inspection unit, and the electrolyte solution to the inside from the outside of the second container And a second pipe member for controlling the pressure in the second container, venting the second container, and controlling the supply of the electrolyte solution to the second container. The sacrificial anode inspection apparatus according to claim 5, wherein:

While setting the insertion length of the first pipe member into the second container to be short and disposing one end portion of the first pipe member in the vicinity of the top wall portion of the second container, The insertion length of the second pipe member into the second container is set to be longer than the insertion length of the first pipe member, and one end of the second pipe member is connected to the second container. 9. The sacrificial anode inspection apparatus according to claim 8, wherein the sacrificial anode inspection apparatus is disposed in the vicinity of the bottom wall portion.

A measurement opening is provided in a bottom wall portion of the second container of the inspection unit, the reference electrode is disposed in correspondence with the measurement opening, and a porous body is disposed in the measurement opening to thereby form the measurement opening. inspection apparatus sacrificial anode according to any one of claims 5 to 9, characterized in that closed by the porous body.