JPH0344859B2 - - Google Patents
Info
- Publication number
- JPH0344859B2 JPH0344859B2 JP63034992A JP3499288A JPH0344859B2 JP H0344859 B2 JPH0344859 B2 JP H0344859B2 JP 63034992 A JP63034992 A JP 63034992A JP 3499288 A JP3499288 A JP 3499288A JP H0344859 B2 JPH0344859 B2 JP H0344859B2
- Authority
- JP
- Japan
- Prior art keywords
- powder
- calcium silicate
- synthetic calcium
- weight
- base material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000378 calcium silicate Substances 0.000 claims description 31
- 229910052918 calcium silicate Inorganic materials 0.000 claims description 31
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 claims description 31
- 239000000463 material Substances 0.000 claims description 27
- 229910000831 Steel Inorganic materials 0.000 claims description 18
- 239000010959 steel Substances 0.000 claims description 18
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 16
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 12
- 238000009749 continuous casting Methods 0.000 claims description 11
- 239000000654 additive Substances 0.000 claims description 10
- 230000000996 additive effect Effects 0.000 claims description 7
- 239000002245 particle Substances 0.000 claims description 7
- 238000005266 casting Methods 0.000 claims description 5
- 239000000377 silicon dioxide Substances 0.000 claims description 5
- 229910052681 coesite Inorganic materials 0.000 claims description 3
- 229910052906 cristobalite Inorganic materials 0.000 claims description 3
- 235000012239 silicon dioxide Nutrition 0.000 claims description 3
- 229910052682 stishovite Inorganic materials 0.000 claims description 3
- 229910052905 tridymite Inorganic materials 0.000 claims description 3
- 239000000843 powder Substances 0.000 description 39
- 239000002994 raw material Substances 0.000 description 33
- 239000000203 mixture Substances 0.000 description 21
- 230000008018 melting Effects 0.000 description 14
- 238000002844 melting Methods 0.000 description 14
- 239000000126 substance Substances 0.000 description 7
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- 238000002425 crystallisation Methods 0.000 description 6
- 230000008025 crystallization Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 230000004907 flux Effects 0.000 description 6
- 238000002156 mixing Methods 0.000 description 4
- 239000011802 pulverized particle Substances 0.000 description 4
- 239000002893 slag Substances 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 239000010436 fluorite Substances 0.000 description 3
- 230000005484 gravity Effects 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 235000017550 sodium carbonate Nutrition 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910018068 Li 2 O Inorganic materials 0.000 description 2
- 229910021538 borax Inorganic materials 0.000 description 2
- WUKWITHWXAAZEY-UHFFFAOYSA-L calcium difluoride Chemical compound [F-].[F-].[Ca+2] WUKWITHWXAAZEY-UHFFFAOYSA-L 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 239000004328 sodium tetraborate Substances 0.000 description 2
- 235000010339 sodium tetraborate Nutrition 0.000 description 2
- OBSZRRSYVTXPNB-UHFFFAOYSA-N tetraphosphorus Chemical compound P12P3P1P32 OBSZRRSYVTXPNB-UHFFFAOYSA-N 0.000 description 2
- 239000005909 Kieselgur Substances 0.000 description 1
- -1 Li 2 CO 3 Chemical compound 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000010459 dolomite Substances 0.000 description 1
- 229910000514 dolomite Inorganic materials 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 229910021382 natural graphite Inorganic materials 0.000 description 1
- 239000010451 perlite Substances 0.000 description 1
- 235000019362 perlite Nutrition 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 239000011044 quartzite Substances 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 239000010456 wollastonite Substances 0.000 description 1
- 229910052882 wollastonite Inorganic materials 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Continuous Casting (AREA)
Description
［産業上の利用分野］
本発明は鋼の連続鋳造用添加剤用基材及び該基
材を使用する鋼の連続鋳造用鋳型添加剤に関す
る。
［従来の技術］
鋼の連続鋳造用鋳型添加剤（以下、パウダーと
略称する）はポルトランドセメント、黄リンスラ
グ、合成珪酸カルシウム、ウオラストナイトなど
を主原料とし、必要に応じてSiO2質原料を加え、
更に、ソーダ灰、硼砂、水晶石、ホタル石などの
フラツクス原料、溶融速度調整剤としての炭素質
原料を含有してなる。
パウダーは鋳型内へ注入された溶鋼表面上へ添
加され、種々の役割を果たしながら消費される。
特に、鋳型と凝固シエルの潤滑、溶鋼中から
浮上する介在物の溶解及び吸収、溶鋼の保温な
どがパウダーの主要な役割である。
我国における連続鋳造用技術の進展は目覚し
く、HCR（ホツトチヤージ）、HDR（ホツトダイ
レクトローリング）比率の向上、高速鋳造化など
が積極的に進められている。従つて、鋳片品質や
操業安定度に影響するパウダーに対する要求も一
段と厳しいものがあり、求められるパウダーは多
種多様となつている。
前述したパウダーの役割のうち及びはパウ
ダーの軟化点、粘度などの特性を調整することが
最重要であり、これにはパウダーの化学組成の選
定が肝要である。一方、の溶鋼保温については
炭素質原料によつて調整される溶融速度や嵩比
重、拡がり性などの粉体特性が重要である。
［発明が解決しようとする課題］
連続鋳造操業で重要な役割を有すパウダーに対
する要求は増々厳しくなつている。特にパウダー
の品質安定度は重要であり、品質の変化による鋳
片品質の低下、ブレイクアウト（以下、B.O.と
いう）に代表される操業トラブルは歩留り低下、
生産性低下の原因であり、パウダーは厳重な品質
管理はもとより、原料の選定に細心の注意を要す
る。従つて、最近では不純物（Fe2O3、Ｓなど）
が少なく、成分が安定している黄リンスラグや合
成珪酸カルシウムがパウダーの基材として使用さ
れている。
しかし、これらの原料はガラス状であるため、
粉砕粒の密度が高く、パウダーの保温性が損なわ
れる欠点を有している。更に、粉砕効率が悪く、
第２図に示すように粉砕粒子は鋭利な角を有して
おり、人体に対する影響が懸念され、粉体として
も拡がり性が劣る。故に、パウダー基材原料とし
て問題がある。
［課題を解決するための手段］
本発明者らはこれらの従来の原料の欠点を改良
すべく種々検討した結果、原料粒子内に空〓を有
する結晶質合成珪酸カルシウムがパウダーの基材
原料として好ましいことを見出した。
即ち、本発明はCaO／SiO2重量比が1.1〜3.0の
結晶質合成珪酸カルシウムであつて、該結晶合成
珪酸カルシウム粒子内に空〓を生成せしめたこと
を特徴とする鋼の連続鋳造用鋳型添加剤用基材に
係る。
更に、本発明はCaO／SiO2重量比が1.1〜3.0の
結晶質合成珪酸カルシウムであつて、該結晶質合
成珪酸カルシウム粒子内に空〓を生成せしめた鋼
の連続鋳造用鋳型添加剤用基材を少なくとも50重
量％以上含有してなることを特徴とする鋼の連続
鋳造用添加剤に係る。
［作用］
一般に、黄リンスラグの如き基材原料は、粒子
内に空〓を含まず高い密度を有しており、また、
仮に空〓を有していてもいわゆる独立した密閉気
孔であるために優れた断熱効果は期待出来ない。
本発明者らはCaO／SiO2重量比1.1〜3.0の珪酸カ
ルシウムを結晶化させることにより結晶粒界に間
〓を生成せしめ、高い断熱効果を有すパウダー基
材原料を得た。
本発明による結晶質合成珪酸カルシウムは石灰
石、ドロマイト、珪石、粘土、ガラス粉、ホタル
石、ソーダ灰などを所定の化学組成になるよう配
合し、電気炉などで溶融後徐冷して結晶化するこ
とにより容易に得られる。また、溶融水砕品をト
ンネルキルン等で600〜1200℃で再加熱すること
によつても目的とする結晶質合成珪酸カルシウム
を得ることができる。
なお、Fe2O3除去の目的でカーボン原料を添加
することもできる。
本発明に係る基材は第１図に示すように粉砕粒
子内に空〓を有しており、それによつて断熱性
が良く；粉砕効率が良く；粉砕粒が丸見を帯
びており拡がり性が良く；従来の非晶質原料の
ように鋭利な角を有する粒が少なく人体に対する
影響が小さいなどの利点を有しており、パウダー
原料として好ましい。
また、本発明に係る基材を少なくとも50％以上
含有するパウダーは該基材の特長である断熱性が
付与され、モールド溶鋼の温度低下を防止でき、
ノロカミ、ピンホールなどの鋳片欠陥が防止でき
る。また、自動供給装置で従来の非晶質原料系パ
ウダーを使用すると金物の摩耗が大きいことが知
られているが、本発明に係る結晶質合成珪酸カル
シウム基材は摩耗による金物の損傷が非常に小さ
いことも特徴であり、拡がり性が良いため、自動
供給に適する。
本発明に係る結晶質合成珪酸カルシウム基材の
もつ上述の特徴は結晶質であることと粒子内に存
在する空〓によるものであるが、この空〓は珪酸
カルシウム溶融物が急速に結晶化する際に固体／
液体間に密度差を生じるために生成すると考えら
れる。従つて、本発明に係る基材原料の組成とし
ては、CaO／SiO2重量比を比較的高くし、結晶
化温度を下げたり、結晶化速度を遅らせる成分を
減じることが必要である。
ここで本発明に使用する結晶質合成珪酸カルシ
ウムの組成について述べる。CaO／SiO2重量比
は1.1以上とする。これはCaO／SiO2重量比が1.1
未満では、充分に結晶化せず、目的とする含空〓
原料は得られないためである。また、CaO／
SiO2重量比が3.0を超えると、溶解時間が長くな
り、作業性が悪化するためCaO／SiO2重量比は
1.1〜3.0が好ましい。また、Al2O3は結晶化を阻
害する成分であり、８％以下、好ましくは５％以
下に制限する必要がある。
更に、Fe2O3は鋼中成分と反応し、鋼の汚染原
因となるため、本発明に係る結晶質合成珪酸カル
シウム中のFe2O3含量は１％以下、好ましくは0.3
％以下に制限する必要がある。
Ｆは溶融物製造時の粘度を調整し、作業性を改
善する目的及び結晶化促進のため添加するが、１
％以下では顕著な効果が少なく、また、過剰に添
加すると溶融容器の損傷が大きく、また、蒸発に
よる組成変化も大きくなる。従つて、結晶質珪酸
カルシウム中のＦ量は１〜13％、好ましくは２〜
11％が良い。
TiO2やMgOを結晶化促進剤として添加するこ
とができるが、過剰に添加するとパウダーとした
時の溶融状態が悪化するため、TiOの添加量は５
％以下、MgOの添加量は20％以下に限定される。
更に、作業性改善を目的とし、Na2O、K2O、
Li2O、B2O3、MnOなどのフラツクス成分を添加
し、合成珪酸カルシウムを溶融する際の粘度、融
点を調整することもできるが、容器の損傷や蒸発
を考慮し、その合計量は15％以下とすることが好
ましい。
本発明のパウダーは以下に示すような基材原
料、SiO2質原料、フラツクス原料及び炭素質原
料より構成されている。
基材原料：結晶質合成珪酸カルシウム。
SiO2質原料：パーライト、フライアツシユ、珪
砂、ガラス粉、珪藻土など。
フラツクス原料：ソーダ灰、Li2CO3、NaF、
Na3AlF6、ホタル石、BaCO3、MgCO3、
MgF2、硼砂など。
炭素質原料：コークス粉、カーボンブラツク、天
然黒鉛など。
また、パウダーは鋳造速度、鋳型サイズ、鋼
種、鋳造温度などの鋳造条件に応じて軟化点、融
点、粘度、表面張力、結晶化温度、溶融速度など
の溶融特性を調整する必要がある。これらの特性
はパウダーの化学組成によつて支配されており、
上述のような各原料を所定の化学組成になるよう
に配合する必要がある。
本発明の鋼の連続鋳造用鋳型添加剤（パウダ
ー）の化学組成は以下の通りである。
CaO＝25〜45重量％、SiO2＝20〜50重量％、
CaO／SiO2重量比＝0.7〜1.5、Al2O3＝０〜10重
量％、Fe2O3＝0.1〜2.0重量％、MgO＝０〜10重
量％、Na2O＋K2O＋Li2O＝３〜25重量％、Ｆ＝
２〜15重量％、B2O3＝０〜10重量％、MnO＝０
〜５重量％、BaO＝０〜15重量％、Ｃ＝0.5〜10
重量％。
上述の化学組成をもつ本発明によるパウダーは
結晶質合成珪酸カルシウム基材原料50重量％以
上、SiO2質原料０〜30重量％、フラツクス原料
０〜30重量％及び炭素質原料0.5〜８重量％を配
合することにより構成することができる。
結晶質合成珪酸カルシウムの添加配合量が50重
量％未満であると、合成珪酸カルシウムの特徴で
ある成分の均一性、安定性が損なわれるために好
ましくない。
SiO2質原料はパウダーの嵩比重、CaO／SiO2
を調整するために使用するものであり、SiO2質
原料の添加配合量が30重量％を超えると嵩比重が
小さくなりすぎ、粉塵発生量が多くなり好ましく
ない。
フラツクス原料は溶融特性を調整するために添
加配合する必要があるが、過剰に添加すると溶融
時の蒸発による組成変化があり、更に、溶鋼を鋳
型内へ注入する浸漬ノズルを激しく損傷するため
に、添加配合量の上限は30重量％程度が好まし
い。
炭素質原料はパウダーの溶融速度を調整するた
めに添加するが、添加配合量が0.5重量％未満で
は実質的に添加効果がなく、８重量％を超えると
溶融速度が遅くなり過ぎるために好ましくない。
本発明によるパウダーは上述のような化学組成
になるように各原料を配合した後、Ｖ型ミキサー
やナウタミキサーで均一に混合することにより得
られる（粉末パウダー）。また、原料混合物を加
水混練し、押出式造粒機によつて柱状体の顆粒を
得たり、混合物をスラリー化したのち、スプレー
造粒法により球状のパウダーを得ることもでき
る。
［実施例］
実施例
結晶質合成珪酸カルシウム基材原料の製造
以下の第１表に記載する配合をもつ原料混合物
を電気炉中で連続溶解により1650〜1700℃に加熱
することにより溶融し、得られた溶融物を徐冷
し、充分結晶化させボールミルで100メツシユ以
下に粉砕して結晶質合成珪酸カルシウム基材原料
を得た。また、溶融物を600〜1200℃で再結晶化
させることにより目的とする基材原料を得ること
もできる。
得られた合成珪酸カルシウムの組成を第２表に
記載する。
[Industrial Application Field] The present invention relates to a base material for an additive for continuous casting of steel and a mold additive for continuous casting of steel using the base material. [Prior art] Mold additives for continuous casting of steel (hereinafter abbreviated as powder) are mainly made of Portland cement, yellow phosphorus slag, synthetic calcium silicate, wollastonite, etc., and SiO 2 material is added as necessary. In addition,
Furthermore, it contains a flux raw material such as soda ash, borax, quartzite, and fluorite, and a carbonaceous raw material as a melting rate regulator. The powder is added onto the surface of the molten steel that is injected into the mold and is consumed while performing various functions.
In particular, the main roles of the powder include lubricating the mold and solidification shell, dissolving and absorbing inclusions floating from the molten steel, and keeping the molten steel warm. Continuous casting technology has made remarkable progress in Japan, and efforts are being made to improve HCR (Hot Charge) and HDR (Hot Direct Rolling) ratios, as well as high-speed casting. Therefore, the requirements for powder that affect slab quality and operational stability are becoming even more severe, and the powders that are required are becoming more diverse. Among the roles of the powder mentioned above, the most important one is to adjust the properties such as the softening point and viscosity of the powder, and selection of the chemical composition of the powder is essential for this purpose. On the other hand, powder properties such as melting rate, bulk specific gravity, and spreadability, which are adjusted by carbonaceous raw materials, are important for heat retention of molten steel. [Problems to be Solved by the Invention] Requirements for powder, which plays an important role in continuous casting operations, are becoming increasingly strict. In particular, the quality stability of powder is important, and operational problems such as a decline in slab quality due to quality changes and breakouts (hereinafter referred to as BO) can lead to a decrease in yield,
This is the cause of reduced productivity, and powder requires not only strict quality control but also careful selection of raw materials. Therefore, recently, impurities (Fe 2 O 3 , S, etc.)
Yellow phosphorus slag and synthetic calcium silicate are used as powder base materials because of their low content and stable composition. However, since these raw materials are glassy,
The disadvantage is that the density of the crushed grains is high, which impairs the heat retention properties of the powder. Furthermore, the grinding efficiency is poor,
As shown in FIG. 2, the pulverized particles have sharp edges, and there is concern that they may affect the human body, and even as a powder, they have poor spreadability. Therefore, there is a problem as a powder base material raw material. [Means for Solving the Problems] As a result of various studies to improve the drawbacks of these conventional raw materials, the present inventors have found that crystalline synthetic calcium silicate, which has voids in the raw material particles, can be used as a base raw material for powder. I found something favorable. That is, the present invention provides a mold for continuous casting of steel, which is made of crystalline synthetic calcium silicate having a CaO/SiO 2 weight ratio of 1.1 to 3.0, and is characterized in that voids are formed in the crystalline synthetic calcium silicate particles. Pertains to base materials for additives. Furthermore, the present invention provides a base for a mold additive for continuous casting of steel, which is a crystalline synthetic calcium silicate having a CaO/SiO 2 weight ratio of 1.1 to 3.0, and in which voids are formed in the crystalline synthetic calcium silicate particles. The present invention relates to an additive for continuous casting of steel, characterized in that it contains at least 50% by weight of a metal. [Function] In general, base materials such as yellow rinsing slag have high density and do not contain voids within the particles, and
Even if it has pores, it cannot be expected to have an excellent heat insulating effect because it is a so-called independent closed pore.
The present inventors crystallized calcium silicate with a CaO/SiO 2 weight ratio of 1.1 to 3.0 to generate gaps at grain boundaries, thereby obtaining a powder base material having a high heat insulating effect. The crystalline synthetic calcium silicate according to the present invention is produced by blending limestone, dolomite, silica stone, clay, glass powder, fluorspar, soda ash, etc. to a predetermined chemical composition, melting it in an electric furnace, and then slowly cooling it to crystallize it. can be easily obtained by The desired crystalline synthetic calcium silicate can also be obtained by reheating the molten granulated product at 600 to 1200°C in a tunnel kiln or the like. Note that a carbon raw material can also be added for the purpose of removing Fe 2 O 3 . As shown in Fig. 1, the base material according to the present invention has voids in the pulverized particles, which provides good heat insulation; good pulverization efficiency; and the roundness of the pulverized particles, allowing for easy spreading. It has the advantage of having fewer grains with sharp edges unlike conventional amorphous raw materials, and has less impact on the human body, and is therefore preferable as a powder raw material. Further, the powder containing at least 50% or more of the base material according to the present invention is given the heat insulation property, which is a feature of the base material, and can prevent the temperature of the molded molten steel from decreasing.
It is possible to prevent slab defects such as grooves and pinholes. In addition, it is known that when conventional amorphous raw material powder is used in an automatic feeding device, there is a large amount of wear on hardware, but the crystalline synthetic calcium silicate base material according to the present invention is extremely susceptible to damage to hardware due to wear. It is also characterized by its small size and good spreadability, making it suitable for automatic feeding. The above-mentioned characteristics of the crystalline synthetic calcium silicate base material according to the present invention are due to its crystalline nature and the presence of voids within the particles, and these voids allow the calcium silicate melt to rapidly crystallize. Sometimes solid/
It is thought that this occurs due to the density difference between the liquids. Therefore, as for the composition of the base material according to the present invention, it is necessary to make the CaO/SiO 2 weight ratio relatively high, lower the crystallization temperature, and reduce the components that retard the crystallization rate. Here, the composition of the crystalline synthetic calcium silicate used in the present invention will be described. The CaO/SiO 2 weight ratio is 1.1 or more. This means that the CaO/SiO 2 weight ratio is 1.1.
If the amount is less than
This is because raw materials cannot be obtained. Also, CaO/
If the SiO 2 weight ratio exceeds 3.0, the dissolution time becomes longer and workability deteriorates, so the CaO/SiO 2 weight ratio is
1.1-3.0 is preferred. Furthermore, Al 2 O 3 is a component that inhibits crystallization, and needs to be limited to 8% or less, preferably 5% or less. Furthermore, since Fe 2 O 3 reacts with components in steel and causes contamination of the steel, the Fe 2 O 3 content in the crystalline synthetic calcium silicate according to the present invention is 1% or less, preferably 0.3.
% or less. F is added to adjust the viscosity during production of the melt, improve workability, and promote crystallization, but 1
If it is less than %, there will be little noticeable effect, and if it is added in excess, the melting container will be seriously damaged and the composition will change significantly due to evaporation. Therefore, the amount of F in crystalline calcium silicate is 1 to 13%, preferably 2 to 13%.
11% is good. TiO 2 and MgO can be added as crystallization promoters, but if added in excess, the molten state will deteriorate when powdered, so the amount of TiO added should be 5
% or less, and the amount of MgO added is limited to 20% or less. Furthermore, for the purpose of improving workability, Na 2 O, K 2 O,
It is also possible to adjust the viscosity and melting point when melting synthetic calcium silicate by adding flux components such as Li 2 O, B 2 O 3 and MnO, but the total amount must be adjusted to avoid damage to the container and evaporation. It is preferably 15% or less. The powder of the present invention is composed of a base raw material, a SiO 2 raw material, a flux raw material, and a carbonaceous raw material as shown below. Base material raw material: Crystalline synthetic calcium silicate. SiO2 raw materials: perlite, fly ash, silica sand, glass powder, diatomaceous earth, etc. Flux raw materials: soda ash, Li 2 CO 3 , NaF,
Na 3 AlF 6 , Fluorite, BaCO 3 , MgCO 3 ,
MgF 2 , borax, etc. Carbonaceous raw materials: coke powder, carbon black, natural graphite, etc. Furthermore, it is necessary to adjust the melting characteristics of the powder, such as softening point, melting point, viscosity, surface tension, crystallization temperature, and melting rate, according to casting conditions such as casting speed, mold size, steel type, and casting temperature. These properties are controlled by the chemical composition of the powder.
It is necessary to mix the above-mentioned raw materials to have a predetermined chemical composition. The chemical composition of the mold additive (powder) for continuous casting of steel of the present invention is as follows. CaO = 25-45% by weight, SiO2 = 20-50% by weight,
CaO/SiO 2 weight ratio = 0.7 to 1.5, Al 2 O 3 = 0 to 10 weight %, Fe 2 O 3 = 0.1 to 2.0 weight %, MgO = 0 to 10 weight %, Na 2 O + K 2 O + Li 2 O = 3 ~25% by weight, F=
2-15% by weight, B 2 O 3 = 0-10% by weight, MnO = 0
~5% by weight, BaO=0-15% by weight, C=0.5-10
weight%. The powder according to the present invention having the above-mentioned chemical composition contains at least 50% by weight of crystalline synthetic calcium silicate base material, 0 to 30% by weight of SiO 2 material, 0 to 30% by weight of flux material, and 0.5 to 8% by weight of carbonaceous material. It can be configured by blending. If the amount of crystalline synthetic calcium silicate added is less than 50% by weight, it is not preferable because the uniformity and stability of the components, which are characteristics of synthetic calcium silicate, will be impaired. SiO 2 raw material is bulk specific gravity of powder, CaO/SiO 2
It is used to adjust the amount of SiO 2 raw material added, and if the amount added exceeds 30% by weight, the bulk specific gravity becomes too small and the amount of dust generated increases, which is not preferable. It is necessary to add flux raw materials to adjust the melting characteristics, but if excessively added, the composition will change due to evaporation during melting, and furthermore, it will severely damage the immersion nozzle that injects molten steel into the mold. The upper limit of the amount added is preferably about 30% by weight. Carbonaceous raw materials are added to adjust the melting rate of the powder, but if the amount added is less than 0.5% by weight, there is virtually no effect of the addition, and if it exceeds 8% by weight, the melting rate becomes too slow, which is not preferable. . The powder according to the present invention is obtained by blending each raw material to have the above-mentioned chemical composition and then uniformly mixing the mixture using a V-type mixer or a Nauta mixer (powder powder). Alternatively, the raw material mixture can be kneaded with water to obtain columnar granules using an extrusion granulator, or the mixture can be slurried and then spherical powder can be obtained by spray granulation. [Example] Example Production of crystalline synthetic calcium silicate base material A raw material mixture having the composition listed in Table 1 below was melted by heating to 1650 to 1700°C by continuous melting in an electric furnace. The resulting melt was slowly cooled, sufficiently crystallized, and ground into 100 meshes or less using a ball mill to obtain a crystalline synthetic calcium silicate base material. Moreover, the desired base material raw material can also be obtained by recrystallizing the melt at 600 to 1200°C. The composition of the obtained synthetic calcium silicate is shown in Table 2.
【表】【table】
【表】【table】
【表】
上述のようにして得られた結晶質合成珪酸カル
シウムを基材原料とし、以下の第３表に記載する
配合をもつ原料混合物をＶ型ミキサーで配合する
ことにより本発明品のパウダー及び比較品のパウ
ダーを製造した。
なお、得られたパウダーの組成及び諸特性を第
３表に併記する。[Table] Using the crystalline synthetic calcium silicate obtained as described above as a base raw material, a raw material mixture having the composition shown in Table 3 below is blended in a V-type mixer to produce the powder and the product of the present invention. A comparative powder was produced. The composition and various properties of the obtained powder are also listed in Table 3.
【表】
［発明の効果］
本発明のパウダーに使用する合成珪酸カルシウ
ム基材原料は結晶質で粉砕粒子内に空〓を有して
いるため、断熱性に優れ、また、粉砕効率がよく
粉砕粒は比較的丸みを帯びているため、拡がり性
が良くさらに人体に対する影響が小さい。従つ
て、該基材原料を少なくとも50％以上含む本発明
のパウダーは以下のような特徴を有する。
保温性にすぐれ、ノロカミ、ピンホールが少
ない。
拡がり性が良く、スラグベアーやB.O.が少
ない。
Fe2O3量が少なく安定した潤滑性を有する。
金物の摩耗が少なく拡がり性が良いため自動
供給に適している。
成分を均一にすることができる。[Table] [Effects of the Invention] The synthetic calcium silicate base material used for the powder of the present invention is crystalline and has voids in the pulverized particles, so it has excellent heat insulation properties and has good pulverization efficiency. Since the grains are relatively rounded, they spread well and have little effect on the human body. Therefore, the powder of the present invention containing at least 50% of the base material has the following characteristics. It has excellent heat retention and has few curls and pinholes. Good spreadability, low slag bear and BO. Has stable lubricity due to low Fe 2 O 3 content. It is suitable for automatic feeding because it has little wear on metal parts and has good spreadability. Ingredients can be made uniform.
第１図は本発明に係る結晶質合成珪酸カルシウ
ム基材粉砕品の模式図であり、第２図は従来の基
材粉砕品の模式図である。
FIG. 1 is a schematic diagram of a pulverized crystalline synthetic calcium silicate base material according to the present invention, and FIG. 2 is a schematic diagram of a conventional pulverized base material.
Claims (1)
酸カルシウムであつて、該結晶質合成珪酸カルシ
ウム粒子内に空〓を生成せしめたことを特徴とす
る鋼の連続鋳造用鋳型添加剤用基材。 ２ CaO／SiO2重量比が1.1〜3.0の結晶質合成珪
酸カルシウムであつて、該結晶質合成珪酸カルシ
ウム粒子内に空〓を生成せしめてなる鋼の連続鋳
造用鋳型添加剤用基材を少なくとも50重量％以上
含有してなることを特徴とする鋼の連続鋳造用添
加剤。[Claims] 1. A steel series comprising crystalline synthetic calcium silicate having a CaO/ SiO2 weight ratio of 1.1 to 3.0, characterized in that voids are formed in the crystalline synthetic calcium silicate particles. Base material for mold additives for casting. 2. At least a base material for a mold additive for continuous casting of steel, which is made of crystalline synthetic calcium silicate having a CaO/SiO 2 weight ratio of 1.1 to 3.0, and in which voids are formed in the crystalline synthetic calcium silicate particles. An additive for continuous casting of steel characterized by containing 50% by weight or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63034992A JPH01212714A (en) | 1988-02-19 | 1988-02-19 | Base material in mold additive for steel continuous casting and additive |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63034992A JPH01212714A (en) | 1988-02-19 | 1988-02-19 | Base material in mold additive for steel continuous casting and additive |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01212714A JPH01212714A (en) | 1989-08-25 |
| JPH0344859B2 true JPH0344859B2 (en) | 1991-07-09 |
Family
ID=12429639
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63034992A Granted JPH01212714A (en) | 1988-02-19 | 1988-02-19 | Base material in mold additive for steel continuous casting and additive |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01212714A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009195951A (en) * | 2008-02-21 | 2009-09-03 | Sumitomo Metal Ind Ltd | Continuous casting method for steel |
-
1988
- 1988-02-19 JP JP63034992A patent/JPH01212714A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01212714A (en) | 1989-08-25 |
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