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JP6553900B2 - Evaluation method for fractured surface of plant members - Google Patents
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JP6553900B2 - Evaluation method for fractured surface of plant members - Google Patents

Evaluation method for fractured surface of plant members Download PDF

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JP6553900B2
JP6553900B2 JP2015048490A JP2015048490A JP6553900B2 JP 6553900 B2 JP6553900 B2 JP 6553900B2 JP 2015048490 A JP2015048490 A JP 2015048490A JP 2015048490 A JP2015048490 A JP 2015048490A JP 6553900 B2 JP6553900 B2 JP 6553900B2
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貴信 星川
貴信 星川
建太郎 橋本
建太郎 橋本
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Mitsubishi Heavy Industries Ltd
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Description

本発明は、プラント部材の破断面評価方法に関するものである。   The present invention relates to a method of evaluating a fracture surface of a plant member.

例えば、プラントの破断等の損傷調査および保守管理の観点から機器等の部材に破断が生じた場合、同様の破断でも時期が違えば破断要因が異なる可能性があるため、破断した時期を推定又は把握することが必要である。   For example, if a breakage occurs in a member such as equipment from the viewpoint of damage investigation such as plant breakage and maintenance management, the cause of the breakage may be different if the time is different even for the same breakage. It is necessary to grasp.

このため、従来においては、化学プラントや発電プラントにおける配管等の破断を非破壊的手法で検査する技術が提案されている(特許文献1)。   For this reason, in the related art, there has been proposed a technique for inspecting fractures of piping or the like in a chemical plant or a power plant by a nondestructive method (Patent Document 1).

特開平10−123106号公報JP 10-123 106 A

しかしながら、現状の機器点検に際し、プラント設備の構造においては、破断の程度を非破壊で確認できない場合には、破断の疑いの大きい機器等の部材を破壊手法、例えば内部より検査対象部材を引っ張る等により取り出して判断することも少なくない。   However, in the current equipment inspection, if the degree of breakage cannot be confirmed in a non-destructive manner in the structure of the plant facility, a member such as a device with a high suspicion of breakage is broken, for example, the member to be inspected is pulled inside It is not uncommon to take out and judge by

このような場合、運転中に発生した破断と、取り出し時に発生した破断との区別が困難な場合がある。   In such a case, it may be difficult to distinguish between a fracture occurring during operation and a fracture occurring upon removal.

このため、プラント装置の内部から検査対象部材を破壊せずに、取り出すことを簡易に行うように構造変更する場合には、プラント設備の大幅な設計変更が余儀なくされ、問題となる。   For this reason, in the case of changing the structure so that the inspection target member can be easily taken out without destroying the member to be inspected from the inside of the plant apparatus, a significant design change of the plant facility is inevitably caused, which causes a problem.

よって、プラント設備の装置の構造には変更がなく、破壊手法で検査対象部材を取り出した場合であっても、破断時期を把握し、破断原因をより正確に評価する技術の確立が切望されている。   Therefore, there is no change in the structure of the plant equipment, and even when the inspection target member is taken out by the destruction method, it is desired to establish a technique for grasping the fracture time and more accurately evaluating the cause of the fracture. There is.

本発明は、前記問題に鑑み、破断時期を把握し、破断原因をより正確に評価することができるプラント部材の破断面評価方法を提供することを課題とする。   An object of the present invention is to provide a fracture surface evaluation method of a plant member capable of grasping the fracture time and more accurately evaluating the fracture cause in view of the above-mentioned problems.

上述した課題を解決するための本発明の第1の発明は、プラント設備内の部材の破断面を評価するプラント部材の破断面評価方法であって、プラント運転の終了後に、検査対象部材を内部より取り出す部材取り出し工程と、取り出した検査対象部材に破断面がある場合、その破断面の変質層を評価する変質層評価工程とを有し、前記変質層評価工程において、検査対象部材の破断部又はき裂先端部に運転時に生成される変質層の進展が存在する場合に、当該検査対象部材の当該破断が運転時に発生したものであると判定し、前記検査対象部材の破断部に運転時に生成される変質層の進展が存在しない場合に、部材の当該破断が部材取り出し時に発生したものであると判定することを特徴とするプラント部材の破断面評価方法にある。   A first aspect of the present invention for solving the above-described problem is a method for evaluating a fracture surface of a plant member for evaluating a fracture surface of a member in a plant facility. If the extracted inspection target member has a fractured surface, it has a modified layer evaluation step for evaluating the altered layer of the fractured surface. In the altered layer evaluation step, the fracture portion of the inspection target member Alternatively, when there is a development of a deteriorated layer generated during operation at the crack tip, it is determined that the fracture of the inspection target member has occurred during operation, and the fracture portion of the inspection target member is determined during operation. In the method for evaluating a fracture surface of a plant member, it is determined that the fracture of the member occurs when the member is taken out when there is no progress of the generated altered layer.

第2の発明は。第1の発明において、前記変質層の進展度合いを、プラント内部環境を基に検量線として予め求めておき、前記破断部の進展度合いを前記検量線から判断することを特徴とするプラント部材の破断面評価方法にある。   The second invention. In the first invention, the degree of progress of the altered layer is obtained in advance as a calibration curve based on the internal environment of the plant, and the degree of progress of the fracture portion is determined from the calibration curve. It is in the section evaluation method.

本発明によれば、破断時期を把握し、破断原因をより正確に評価することができる。   According to the present invention, it is possible to grasp the breakage time and to more accurately evaluate the breakage cause.

図1は、実施例1に係るプラント部材の破断面評価方法のフロー図である。FIG. 1 is a flowchart of a method for evaluating a fracture surface of a plant member according to a first embodiment. 図2は、運転時に変質層が表面(環境側との境界面)から生成/進展を有する部材の概略図である。FIG. 2 is a schematic view of a member in which the altered layer has a formation / evolution from the surface (the interface with the environment side) during operation. 図3は、プラント運転時に破断が発生する場合の部材の内部構造を示す図である。FIG. 3 is a view showing the internal structure of a member when breakage occurs during plant operation. 図4は、プラント運転終了後の取り出し時に破断が発生する場合の部材の内部構造を示す図である。FIG. 4 is a view showing the internal structure of the member in the case where breakage occurs at the time of removal after the end of plant operation. 図5は、部材に対して運転時破断部と運転後破断部とが存在する一例を示す概略図である。FIG. 5 is a schematic view showing an example in which an operating fracture portion and an after-operation fracture portion exist with respect to a member. 図6は、プラント運転時間と変質層の進展深さとの関係の一例を示す検量線図である。FIG. 6 is a calibration diagram showing an example of the relationship between the plant operation time and the development depth of the altered layer.

以下に添付図面を参照して、本発明の好適な実施例を詳細に説明する。なお、この実施例により本発明が限定されるものではなく、また、実施例が複数ある場合には、各実施例を組み合わせて構成するものも含むものである。   The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The present invention is not limited to the embodiments, and in the case where there are a plurality of embodiments, the present invention also includes those configured by combining the respective embodiments.

本実施例に係るプラント部材の破断面評価方法は、プラント運転の終了後に、検査対象部材を内部より取り出す部材取り出し工程と、取り出した検査対象部材に破断面がある場合、その破断面の変質層を評価する変質層評価工程とを有し、変質層評価工程において、検査対象部材の破断部(亀裂部、割れ部等)又はき裂先端部に運転時に生成される変質層の進展が存在する場合に、当該検査対象部材の当該破断が運転時に発生したものであると判定し、検査対象部材の破断部(亀裂部)に運転時に生成される変質層の進展が存在しない場合に、部材の当該破断が部材取り出し時に発生したものであると判定するものである。   In the fractured surface evaluation method of a plant member according to the present embodiment, a member taking-out step of taking out the inspection object member from the inside after the operation of the plant and the damaged layer of the fractured surface when the taken inspection object member has a fractured surface In the deteriorated layer evaluation step, the development of the deteriorated layer generated during operation is present at the fractured part (cracked part, cracked part, etc.) of the member to be inspected or at the tip of the crack. In the case where it is determined that the fracture of the inspection target member has occurred during operation, and there is no progress of the deteriorated layer generated at the time of operation in the fracture portion (cracked portion) of the inspection target member, It is judged that the said fracture | rupture generate | occur | produced at the time of member extraction.

図1は、実施例1に係るプラント部材の破断面評価方法のフロー図である。以下、図1のプラント部材の破断面評価方法のフロー図を参照して、プラント部材の破断面評価方法を詳述する。
図1に示すように、本実施例に係るプラント設備内の部材の破断面を評価するプラント部材の破断面評価方法は、プラント運転の終了後に、検査対象部材を内部より取り出す部材取り出し工程(S−11)と、取り出した検査対象部材に破断面がある場合、その破断面の変質層を評価する変質層評価工程(S−12)と、変質層評価工程(S−12)での破断部の変質層有無を判断する変質層判断工程(S−13)と、変質層判断工程(S−13)の結果により、検査対象部材の破断部(亀裂部)に運転時の変質層の進展が存在する場合(Yes)に、当該検査対象部材の当該破断が運転時に発生したものであると判定する第1判定工程(S−14)と、検査対象部材の破断部(亀裂部)に運転時の変質層の進展が存在しない場合(No)に、部材の当該破断が部材取り出し時に発生したものであると判定する第2判定工程(S−15)と、を有している。
FIG. 1 is a flowchart of a method for evaluating a fracture surface of a plant member according to the first embodiment. Hereinafter, the fracture surface evaluation method of the plant member will be described in detail with reference to the flow chart of the fracture surface evaluation method of the plant member in FIG. 1.
As shown in FIG. 1, the fractured surface evaluation method of a plant member for evaluating the fractured surface of a member in a plant facility according to the present embodiment is a member taking-out step (S) for taking out a member to be inspected from inside after plant operation is completed. -11) and, when there is a fractured surface in the member to be inspected that has been taken out, the fractured portion in the deteriorated layer evaluation step (S-12) of evaluating the deteriorated layer of the fractured surface and the damaged layer evaluation step (S-12) According to the results of the deteriorated layer judgment step (S-13) for judging the presence or absence of the deteriorated layer and the deterioration layer judgment step (S-13), the development of the deteriorated layer at the time of operation to the fractured part (cracked part) of the inspection object member When it exists (Yes), the first determination step (S-14) of determining that the fracture of the inspection object member occurs at the time of operation, and the operation of the fracture portion (cracked portion) of the inspection object member If there is no progress in the altered layer of (No), The fracture of the wood has a second determination step determines that arose during member extraction (S-15), the.

部材取り出し工程(S−11)は、検査対象部材をプラント内部より取り出す工程であり、プラント運転の終了後に行う。例えば反応容器を一例とすると、内部に挿入された例えば挿入部材に例えばしきり板等が周囲に付設されており、反応容器の取り出し口が小さい場合には、このしきり板がその取り出しの際に、破断により変形することがある。
この変形が、プラント運転時における例えば圧力変動による破断による変形と外見上判断が困難となる。
The member extraction step (S-11) is a step of extracting the inspection object member from the inside of the plant, and is performed after the end of the plant operation. For example, taking the reaction vessel as an example, for example, a breaking plate or the like is attached to the periphery of the insertion member inserted inside, for example, and when the takeout port of the reaction vessel is small, the breaking plate is taken out during its removal. May be deformed by breakage.
This deformation makes it difficult to judge the appearance and deformation due to breakage due to, for example, pressure fluctuation during plant operation.

変質層評価工程(S−12)は、取り出した検査対象部材に破断面がある場合、その破断面の変質層を評価するものである。評価方法は、変質層を評価する公知の評価方法による。
ここで、変質層とは、プラント運転時において、内部環境に応じて、部材として鋼板を例とすると、鋼板の表面近傍に、そのプラント運転内部雰囲気に応じて、発生する化学変化層をいう。例えば変質層としては、窒化層、浸炭層、酸化層、浸食層等を例示することができる。
一般的には、プラント運転時間が増えるのに従い、変質層の形成領域も曝露表面から深くなる。ただし変質層の深さ以外にもプラント稼働時間の経過に伴い変化する性質があるような場合には、その変化を判断材料とするようにしてもよい。
In the deteriorated layer evaluation step (S-12), when there is a fracture surface in the member to be inspected taken out, the deterioration layer on the fracture surface is evaluated. The evaluation method is based on a known evaluation method for evaluating the deteriorated layer.
Here, the degraded layer refers to a chemically changed layer generated in the vicinity of the surface of the steel plate according to the internal atmosphere at the time of operation of the plant, taking the steel plate as an example as a member at the time of plant operation according to the internal environment. For example, examples of the altered layer include a nitride layer, a carburized layer, an oxide layer, and an eroded layer.
In general, as the plant operation time increases, the formation region of the altered layer also becomes deeper from the exposed surface. However, if there is a property that changes with the passage of plant operation time other than the depth of the deteriorated layer, the change may be used as a judgment material.

変質層としては、例えば加熱炉の場合には、例えば酸化層、硫化層、浸炭層、V(バナジウム)アタック層等が発生する。また、脱硫装置の場合には、硫化層、水素浸食層等が発生する。また、水蒸気改質装置の場合には、浸炭層、水素浸食層、V(バナジウム)アタック層等が発生する。またアンモニア合成装置の場合には、窒化層、水素浸食層が発生する。また、ハロゲン化装置の場合には、ハロゲン化腐食層等が発生する。また、過熱器、再熱器の場合には、水蒸気酸化層、V(バナジウム)アタック層、アルカリ硫酸塩腐食層等が発生する。また、廃熱回収器の場合には、アルカリ硫酸塩腐食層が発生する。また、蒸気発生器の場合には、Naによる脱炭層、浸炭層等が発生する。また、熱交換器の場合には、酸化層、浸炭層、脱炭層等が発生する。排ガス浄化装置の場合には、酸化層、鉛(Pb)腐食層等が発生する。また、焼却炉熱交換器の場合には、塩化物−硫酸塩による腐食層等が発生する。   As the altered layer, for example, in the case of a heating furnace, for example, an oxide layer, a sulfide layer, a carburized layer, a V (vanadium) attack layer, and the like are generated. Further, in the case of the desulfurization apparatus, a sulfurized layer, a hydrogen erosion layer and the like are generated. Further, in the case of a steam reforming apparatus, a carburized layer, a hydrogen erosion layer, a V (vanadium) attack layer and the like are generated. In the case of the ammonia synthesis apparatus, a nitrided layer and a hydrogen eroded layer are generated. In the case of a halogenation apparatus, a halogenated corrosion layer or the like is generated. In the case of a superheater or reheater, a steam oxidation layer, a V (vanadium) attack layer, an alkali sulfate corrosion layer, or the like is generated. In the case of a waste heat recovery unit, an alkali sulfate corrosion layer is generated. Further, in the case of a steam generator, a decarburized layer, a carburized layer and the like due to Na are generated. In the case of a heat exchanger, an oxide layer, a carburized layer, a decarburized layer, etc. are generated. In the case of the exhaust gas purification apparatus, an oxide layer, a lead (Pb) corrosion layer and the like are generated. Moreover, in the case of the incinerator heat exchanger, a corrosive layer or the like due to a chloride-sulfate is generated.

例えば変質層として、浸炭層を評価する場合を説明する。浸炭層の評価手法としては、例えば検査対象部材の破断面を研磨し、その後腐食液(例えば塩化第2鉄と塩酸との混合液)に接触させ、その腐食状況を観察して、浸炭層の進展度合いを判断する。   For example, the case where a carburized layer is evaluated as a deteriorated layer will be described. As an evaluation method of the carburized layer, for example, the fracture surface of the member to be inspected is polished, and then contacted with a corrosive liquid (for example, a mixed liquid of ferric chloride and hydrochloric acid), and the corrosion state is observed, Determine the degree of progress.

また、これらの変質層(浸炭層)は,調査対象の母材と比べて硬さなどの機械的性質が異なることが多い。そのため、断面肉厚方向に特定のピッチで硬さ測定を実施し、硬さの分布から変質層の進展度合いを評価することが一般的である。窒化層についても同じことが言える。   In addition, these altered layers (carburized layers) often differ in mechanical properties such as hardness compared with the base material to be investigated. Therefore, it is general to measure the hardness at a specific pitch in the cross-sectional thickness direction and to evaluate the progress of the altered layer from the distribution of hardness. The same is true for the nitrided layer.

変質層判断工程(S−13)は、変質層評価工程(S−12)での破断部における変質層の進展の有無の状況を判断する。
判断は、破断部の破断先端部(溝部の底部)において、変質層があるか否かを判断する。
In the deteriorated layer judgment step (S-13), the state of the presence or absence of the progress of the deteriorated layer at the fracture portion in the deteriorated layer evaluation step (S-12) is judged.
The determination is made as to whether or not there is a deteriorated layer at the front end of the fracture (the bottom of the groove).

第1判定工程(S−14)は、変質層判断工程(S−13)の結果により、検査対象部材の破断部(亀裂部)に運転時の変質層の進展(破断部変質層)が存在する場合(Yes)に、当該検査対象部材の当該破断が運転時に発生したものであると判定する。   The first determination step (S-14) is based on the result of the deteriorated layer determination step (S-13), and the progress of the deteriorated layer during operation (broken portion deteriorated layer) exists in the fractured portion (cracked portion) of the inspection target member. When it is determined (Yes), it is determined that the breakage of the inspection target member has occurred during operation.

第2判定工程(S−15)は、変質層判断工程(S−13)の結果により、検査対象部材の破断部(亀裂部)に運転時の変質層が存在しない場合(No)に、部材の当該破断が部材取り出し時に発生したものであると判定する。   The second determination step (S-15) is a member when the deteriorated layer at the time of operation does not exist in the fractured portion (cracked portion) of the inspection target member according to the result of the deteriorated layer determining step (S-13) (No). It is determined that the breakage of the above occurred at the time of member removal.

図2は、運転時に変質層が表面(環境側との境界面)から生成/進展を有する部材の概略図である。図2に示すように、プラント運転前は、部材11の表面には、変質層は存在しない(図2中、左側参照)。
しかし、プラント運転後は、プラント運転時の内部雰囲気環境において、部材11の表面には母材変質層12が発生する。この母材変質層12は、部材11の表面から所定深さだけ、プラント運転時間に応じて進展が一様に生じる。
FIG. 2 is a schematic view of a member in which an altered layer has generation / progress from the surface (boundary surface with the environment side) during operation. As shown in FIG. 2, the altered layer does not exist on the surface of the member 11 before the plant operation (see the left side in FIG. 2).
However, after the plant operation, the base material altered layer 12 is generated on the surface of the member 11 in the internal atmosphere environment during the plant operation. The base material altered layer 12 is uniformly developed from the surface of the member 11 by a predetermined depth according to the plant operation time.

図3は、プラント運転時に破断が発生する場合の部材の内部構造を示す図である。
図3に示すように、プラント運転時に破断部が発生する場合には、その破断発生までには、すでに運転により母材変質層12が形成されている(図3中、「破断前」)。この際には、深さD1の母材変質層12が、表面から生成/進展する。
FIG. 3 is a diagram showing an internal structure of a member when a fracture occurs during plant operation.
As shown in FIG. 3, when a fractured part occurs during plant operation, the base material deteriorated layer 12 is already formed by the operation until the fracture occurs (“before fracture” in FIG. 3). At this time, the base material altered layer 12 having the depth D1 is generated / advanced from the surface.

その後、運転中において破断が発生すると、部材11の表面に発生している母材変質層12を破って、運転時破断部21が発生する(図3中、「破断発生時」)。   Thereafter, when a fracture occurs during operation, the base material altered layer 12 generated on the surface of the member 11 is broken and a fracture portion 21 during operation is generated (“when fracture occurs” in FIG. 3).

この状態において、プラント運転を継続し、運転が終了すると、運転時破断部21の亀裂の近傍に母材変質層12がさらに進展すると共に、運転時破断部21の亀裂の深さ方向にも所定の運転時の破断部変質層12aが発生する(図3中、「運転終了後」)。これは、亀裂内部の表面から運転時の破断部変質層12aが深さD2だけ変質層が形成されることによる。なお、母材変質層12の進展深さD3は進展深さD1とD2との合計となる。 In this state, the plant operation is continued, and when the operation is finished, the base material deteriorated layer 12 further develops in the vicinity of the crack of the fracture part 21 during operation, and the depth direction of the crack of fracture part 21 during operation is also specified. The fractured portion altered layer 12a during the operation is generated ("after operation" in FIG. 3). This is because the damaged layer 12a at the time of operation is formed from the surface inside the crack by a depth D 2 . The progress depth D 3 of the base material altered layer 12 is the sum of the progress depths D 1 and D 2 .

図4は、プラント運転終了後の取り出し時に破断が発生する場合の部材の内部構造を示す図である。図4に示すように、プラント運転終了後には、プラント運転時に発生した進展深さD3の母材変質層12が部材11に発生しているのみである(図4中、「運転終了後」)。そして、プラント終了後の取り出しの際に、破断部が発生する場合には、部材11の表面に発生している進展深さD3の母材変質層12を破って、運転後破断部22が発生する(図4中、「取り出し後」)。この結果、プラント終了後の取り出しの際においては、部材11の表面に発生した運転後破断部22には、プラント運転により発生した進展深さD3の母材変質層12のみが存在し、図3に示すような運転時破断部21の亀裂部分の深さ方向には所定の運転時の破断部変質層12aが存在しない。 FIG. 4 is a diagram showing an internal structure of a member when a breakage occurs at the time of taking out after the plant operation is completed. As shown in FIG. 4, after the end of the plant operation, only the base material deteriorated layer 12 of the development depth D 3 generated at the time of plant operation is generated in the member 11 (in FIG. ). And when taking out after the end of the plant, if a fractured part occurs, the base material altered layer 12 of the advancing depth D 3 occurring on the surface of the member 11 is broken, and the fractured part 22 after operation Occurs ("after removal" in FIG. 4). As a result, at the time of taking-out after the end of the plant, only the base material altered layer 12 of the development depth D 3 generated by the plant operation exists in the after-operation fracture portion 22 generated on the surface of the member 11. In the depth direction of the cracked portion of the fractured portion 21 as shown in FIG. 3, the fractured affected layer 12a does not exist in the predetermined operation.

図5は、部材に対して運転時破断部と運転後破断部とが同一部材で存在する一例を示す概略図である。図5の上段の図に示すように、運転前は、部材11の表面には母材変質層は存在しない。   FIG. 5 is a schematic view showing an example in which the in-operation fracture portion and the in-operation fracture portion exist in the same member with respect to the member. As shown in the upper drawing of FIG. 5, before the operation, the base material altered layer does not exist on the surface of the member 11.

運転中に部材11の上側に破断が発生する場合には、図5の中段の図に示すように、運転時破断部21の発生がある。   When breakage occurs on the upper side of the member 11 during operation, as shown in the middle drawing of FIG.

その後、運転を継続すると、図5の下段の図に示すように、プラント運転後には、その運転時間に応じて、部材上側に形成された運転時破断部21の深さ方向には、運転時の破断部変質層12aが進展する。   Thereafter, when the operation is continued, as shown in the lower diagram of FIG. 5, after the plant operation, in the depth direction of the operation breakage portion 21 formed on the upper side of the member according to the operation time, The fractured part of the damaged layer 12a develops.

これに対して、プラント運転後の取り出し時の引張の際に、部材の下側に破断が発生する場合には、図5の下段の図に示すように、運転時破断部21が発生する。しかし、この運転後破断部22の深さ方向には、部材11の上側に運転中に形成された運転時破断部21のような運転時の破断部変質層12aが形成されない。   On the other hand, when the fracture occurs on the lower side of the member during the pulling at the time of taking out after the plant operation, as shown in the lower diagram of FIG. However, in the depth direction of the fracture portion 22 after operation, the fracture portion altered layer 12a during operation is not formed on the upper side of the member 11 like the fracture portion 21 during operation.

このように、プラントの運転に伴い窒化や浸炭等の変質層が生成する場合、プラント運転時間と一定の関係をもった深さの変質層が形成される。   As described above, when the altered layer such as nitriding or carburizing is generated along with the operation of the plant, the altered layer having a depth having a certain relationship with the plant operation time is formed.

よって、変質層判断工程(S−13)において、変質層評価工程(S−12)での破断部における変質層の進展の有無の状況を判断することで、破断部の破断先端部(溝部の底部)において、運転時の破断部変質層12aがあるか否かを判断することで、運転中に発生した破断か、取り出し時に発生した破断かの区別を判断することができることとなる。   Therefore, in the deteriorated layer judgment step (S-13), by determining the presence / absence of progress of the deteriorated layer in the fractured portion in the altered layer evaluation step (S-12), the fracture tip portion (groove portion of the fracture portion) is determined. By determining whether or not there is a fractured portion altered layer 12a at the time of operation at the bottom), it is possible to determine whether the fracture has occurred during operation or the fracture occurred at the time of removal.

このように、プラント運転稼働中に破断などの損傷により製品本来の表面以外に、運転時破断部21が生成されると、その破断部の進展方向の領域においても運転時の破断部変質層12aの生成が始まる。   In this way, when the fracture portion 21 during operation is generated in addition to the original surface of the product due to damage such as fracture during plant operation, the fracture portion altered layer 12a during operation is also generated in the region in the direction of progress of the fracture portion. Generation of will begin.

よって、プラント運転中に発生した運転時破断部21においては、通常形成される母材変質層12と、運転時の破断部変質層12aの生成量(表面からの深さ等)が異なるため、運転時断面部21の運転時の破断部変質層12aの様相(進展程度)を比較することで、破断部の発生した時期を把握することが出来る。   Therefore, in the fracture portion 21 at the time of operation that occurred during the plant operation, the amount of formation (depth from the surface, etc.) of the base material altered layer 12 that is normally formed and the fractured portion altered layer 12a during operation is different. By comparing the appearance (the degree of progress) of the fractured part degenerated layer 12a during the operation of the cross-sectional part 21 during operation, it is possible to grasp the time when the fractured part has occurred.

プラント装置から機器を取り出す際には、一般的にはプラントは運転を停止している。このため、プラント運転終了後の取り出し時に、例えば過大な応力を受けて破断した場合、この運転後破断部22の破断面には運転時の破断部変質層12aは生成されない。   The plant is generally shut down when removing equipment from the plant equipment. For this reason, at the time of taking out after the end of the plant operation, for example, when it breaks due to excessive stress, the damaged portion altered layer 12a during operation is not generated on the fracture surface of the fracture portion 22 after operation.

よって、これらを確認することにより、おおよその破断時期を把握できる。これにより、より正確な破断調査を行うことが出来る。   Therefore, by confirming these, it is possible to grasp an approximate break time. This makes it possible to conduct a more accurate fracture survey.

実施例2は、実施例1において、さらに、運転時変質層をもとにして、おおよその破断の発生時間を把握するものである。   In the second embodiment, in the first embodiment, the occurrence time of breakage is roughly grasped based on the operation-time deteriorated layer.

実施例2では、事前に運転環境を模擬した雰囲気で試験を行い変質層の性質(層深さや硬さなど)と運転時間の相関を取得するものである。
図6は、プラントの運転時間(h)と変質層の進展深さとの関係の一例を示す検量線図である。
In the second embodiment, the test is performed in an atmosphere simulating the operating environment in advance to obtain the correlation between the property of the altered layer (such as the layer depth and hardness) and the operating time.
FIG. 6 is a calibration diagram showing an example of the relationship between the plant operation time (h) and the progressing depth of the altered layer.

図6において、変質層評価工程(S−12)での検査結果により、運転時の破断部変質層12aの進展深さの計測結果が例えば深さDとすると、その計測した深さ(D2)に対応する運転時間(t2)を求めることができる。 In FIG. 6, when the measurement result of the development depth of the fractured part of the fractured layer 12a during operation is, for example, the depth D 2 according to the inspection result in the deteriorated layer evaluation step (S-12), the measured depth (D The operation time (t 2 ) corresponding to 2 ) can be obtained.

これにより、破断後に進展した運転時の破断部変質層12aの進展深さからプラント運転時間t2が推定されるので、総プラント運転時間(T)から求めた運転時間(t2)を引くことで、破断部の発生時間を推定することができる。 Thus, the plant operation time t 2 is estimated from the evolution depth of breaks deteriorated layer 12a during the operation the progress after fracture, subtracting the operating time calculated from the total plant operating time (T) (t 2) Thus, the occurrence time of the fracture portion can be estimated.

このように、本実施例によれば、変質層の進展度合いを、プラント内部環境を基に検量線として予め求めておき、実際の破断部の進展度合いを検量線から判断することで、破断部の発生時間を推定することができる。   Thus, according to the present embodiment, the degree of progress of the altered layer is obtained in advance as a calibration curve based on the plant internal environment, and the degree of progress of the actual fractured part is determined from the calibration curve, whereby the fractured part The occurrence time of can be estimated.

11 部材
12 母材変質層
12a 運転時の破断部変質層
21 運転時破断部
22 運転後破断部
DESCRIPTION OF SYMBOLS 11 Member 12 Base material altered layer 12a Fracture part alteration layer during operation 21 Fracture part during operation 22 Fracture part after operation

Claims (1)

プラント設備内の部材の破断面を評価するプラント部材の破断面評価方法であって、
プラント運転の終了後に、検査対象部材を内部より取り出す部材取り出し工程と、
取り出した検査対象部材に破断面がある場合、その破断面の変質層を評価する変質層評価工程とを有し、
前記変質層評価工程において、検査対象部材の破断部又はき裂先端部に運転時に生成される変質層の進展が存在する場合に、当該検査対象部材の当該破断が運転時に発生したものであると判定し、
前記検査対象部材の破断部に運転時に生成される変質層の進展が存在しない場合に、部材の当該破断が部材取り出し時に発生したものであると判定すると共に、
前記変質層の進展度合いを、プラント内部環境を基に検量線として予め求めておき、前記破断部の進展度合いを前記検量線から判断することを特徴とするプラント部材の破断面評価方法。
A fracture surface evaluation method for a plant member for evaluating a fracture surface of a member in a plant facility,
After the plant operation is finished, a member taking-out process for taking out the inspection target member from inside,
If the inspection target member taken out has a fracture surface, it has a deteriorated layer evaluation step for evaluating the deteriorated layer of the fracture surface,
In the degraded layer evaluation step, if the fractured portion of the member to be inspected or the progress of the degenerated layer generated at the time of operation is present at the tip of the crack, the fracture of the member to be inspected is generated at the time of operation Judgment,
When it is determined that the fracture of the member occurs at the time of taking out the member, when there is no progress of the deteriorated layer generated at the time of operation at the fracture portion of the inspection target member .
The fracture surface evaluation method for a plant member , wherein the progress of the deteriorated layer is obtained in advance as a calibration curve based on the internal environment of the plant, and the progress of the fracture portion is judged from the calibration curve .
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