JPH0250908A - Method for preventing intergranular oxidation of high-strength cold-rolled steel sheet - Google Patents
Method for preventing intergranular oxidation of high-strength cold-rolled steel sheetInfo
- Publication number
- JPH0250908A JPH0250908A JP63201765A JP20176588A JPH0250908A JP H0250908 A JPH0250908 A JP H0250908A JP 63201765 A JP63201765 A JP 63201765A JP 20176588 A JP20176588 A JP 20176588A JP H0250908 A JPH0250908 A JP H0250908A
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- winding
- hot
- grain boundary
- rolled
- 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.)
- Pending
Links
- 230000003647 oxidation Effects 0.000 title claims abstract description 46
- 238000007254 oxidation reaction Methods 0.000 title claims abstract description 46
- 238000000034 method Methods 0.000 title claims abstract description 22
- 239000010960 cold rolled steel Substances 0.000 title claims abstract description 18
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 44
- 239000010959 steel Substances 0.000 claims abstract description 44
- 238000004804 winding Methods 0.000 claims abstract description 30
- 238000005098 hot rolling Methods 0.000 claims abstract description 27
- 238000001816 cooling Methods 0.000 claims description 11
- 238000002791 soaking Methods 0.000 claims description 5
- 239000012535 impurity Substances 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 4
- 229910000976 Electrical steel Inorganic materials 0.000 abstract description 8
- 238000005097 cold rolling Methods 0.000 abstract description 8
- 238000005554 pickling Methods 0.000 abstract description 8
- 229910052710 silicon Inorganic materials 0.000 abstract description 8
- 238000000137 annealing Methods 0.000 abstract description 4
- 239000010703 silicon Substances 0.000 abstract description 4
- 238000010791 quenching Methods 0.000 abstract 1
- 230000000171 quenching effect Effects 0.000 abstract 1
- 230000009466 transformation Effects 0.000 description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000005728 strengthening Methods 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- 229910052802 copper Inorganic materials 0.000 description 4
- 239000010949 copper Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000001000 micrograph Methods 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000007373 indentation Methods 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000001131 transforming effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は高強度冷間圧延鋼板の粒界酸化防止方法に関す
るもので、さらに詳しくは、５０ｋｇｆ／ｍｍ２級以」
二の高珪素高強度冷間圧延鋼板の粒界酸化防止方法に関
する。[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for preventing grain boundary oxidation of high-strength cold-rolled steel sheets, and more specifically, to
The present invention relates to a second method for preventing grain boundary oxidation of high-silicon high-strength cold-rolled steel sheets.
［従来技術］
従来より、Ｓｉ含有量の多い高強度冷間圧延鋼板等の製
造においては、熱間圧延後の鋼板表面に粒界酸化が生じ
ることは知られている。[Prior Art] It has been known that grain boundary oxidation occurs on the surface of the hot-rolled steel sheet in the production of high-strength cold-rolled steel sheets with a high Si content.
そして、この粒界酸化は鋼板表面から５０〜１００μ程
度の深さのところに生じ、通常の酸洗によっては除去す
ることが困難であり、そのため酸洗後の冷間圧延におい
て粒界酸化部が剥離してしまい、剥離した鉄粉により冷
間圧延時や連続焼鈍時に鋼板表面に凹凸の押し疵が発生
したり、さらに、鋼板表面に存在ずろ粒界酸化部のミク
ロクラックにより、切り欠き感受性の高い高強度鋼板に
おいては加工性が劣化するという問題がある。This grain boundary oxidation occurs at a depth of about 50 to 100 microns from the surface of the steel sheet, and is difficult to remove by ordinary pickling. The peeled iron powder may cause uneven indentations on the surface of the steel sheet during cold rolling or continuous annealing, and microcracks in the grain boundary oxidation areas that exist on the surface of the steel sheet may cause notch susceptibility. A problem with high strength steel sheets is that workability deteriorates.
また、高珪素鋼は高強度銅板、電気鉄板等によく使用さ
れてきているが、これらの鋼板の熱間圧延はＡｒ３変態
点以上の温度で熱間圧延を終了し、その後第１図に示す
ような冷却パターンで巻き取りが行なわれている。即ち
、冷間圧延高張力鋼板に使用する場合には、冷間圧延時
の荷重負担を軽くずろため、また、電気鉄板においては
ＡＩＮ。In addition, high-silicon steel has been often used for high-strength copper plates, electric iron plates, etc., but hot rolling of these steel plates is completed at a temperature above the Ar3 transformation point, and then the hot rolling process shown in Figure 1 is completed. Winding is performed using a cooling pattern like this. That is, when used in cold-rolled high-strength steel plates, it is used to lightly shift the load during cold rolling, and in electric iron plates, AIN is used.
ＭｎＳ等を析出さ且て材質の向−Ｌを図るため、第１図
Ａに示すように、熱間圧延最終スタンドを出た後、あま
り急冷を行なイつずに６００℃前後の比較的高温度にお
いて巻き取られている。In order to precipitate MnS etc. and to improve the -L direction of the material, as shown in Figure 1A, after exiting the final hot rolling stand, the temperature is relatively low at around 600℃ without rapid cooling. Coiled at high temperature.
また、変態組織を利用した熱間圧延高張力鋼板において
は、マルテンサイトおよびベイナイト等の変態組織を得
るために第１図Ｂに示すように、熱間圧延最終スタンド
を出た後、連続的に冷却し、３００℃程度の低温におい
て、或い（ｊ１第１図Ｃに示すように、所定の温度に保
持して組織の一部に粒界酸化を防止することはできない
。In addition, in hot-rolled high-strength steel sheets that utilize transformation structures, in order to obtain transformation structures such as martensite and bainite, as shown in Figure 1B, after exiting the final hot rolling stand, continuous It is not possible to prevent grain boundary oxidation in a part of the structure by cooling and maintaining it at a predetermined temperature at a low temperature of about 300° C. (j1 as shown in FIG. 1C).
［発明が解決しようとする課題］
本発明は上記に説明した高珪素鋼の粒界酸化を防止する
ための従来技術における種々の問題点に鑑み、本発明者
か鋭意研究を行い、検討を重ねた結果、高珪素鋼の熱間
圧延に際して、その熱間圧延後の急冷により巻き取り温
度を低くすることにより、粒界酸化を防止できることを
見出し、高強度冷間圧延鋼板の粒界酸化防止方法を開発
したのである。[Problems to be Solved by the Invention] In view of the various problems in the conventional techniques for preventing grain boundary oxidation of high-silicon steel explained above, the present inventor has conducted extensive research and repeated examinations. As a result, it was discovered that grain boundary oxidation can be prevented during hot rolling of high-silicon steel by lowering the coiling temperature by rapid cooling after hot rolling, and a method for preventing grain boundary oxidation in high-strength cold-rolled steel sheets was developed. was developed.
「課題を解決するための手段］
本発明に係る高強度冷間圧延鋼板の粒界酸化防止方法は
、
（１） Ｃ０．０５−０，２５ｗｔ％、Ｓｉ ０．５
〜３．０ｗｔ％、Ｍｎ ０５〜３．０ｗｔ％
を含有し、残部Ｆｅおよび不可避不純物からなる鋼を均
熱処理後、熱間圧延を行い、熱間圧延終了後から巻き取
るまでの時間の１／３の時間以内に７００℃以下の温度
に冷却した後、５５０℃以下の温度において巻き取るこ
とを特徴とする高強度をγ−・α変態ざぜた後、再び急
冷して巻き取られている。"Means for Solving the Problems" The method for preventing grain boundary oxidation of high-strength cold-rolled steel sheets according to the present invention is as follows: (1) C0.05-0.25wt%, Si 0.5
After soaking a steel containing ~3.0 wt%, Mn 05~3.0 wt%, and the balance consisting of Fe and unavoidable impurities, hot rolling is performed, and the time from the end of hot rolling to the time of winding is 1/1 After being cooled to a temperature of 700° C. or less within 3 hours, the material is rolled up at a temperature of 550° C. or less.After undergoing a γ-/α transformation to obtain high strength, it is rapidly cooled again and wound up.
しかし、これらの熱間圧延後の冷却方法では、何れの方
法においても粒界酸化を防止することはできず、従って
、このような高珪素銅板においては粒界酸化の発生４−
る鋼板では、酸洗速度を遅くするか、または、機械研削
を酸洗と併用ずろ等の対策が行なわれているが、生産性
が著しく低下するという問題がある。However, none of these cooling methods after hot rolling can prevent grain boundary oxidation, and therefore grain boundary oxidation may occur in such high-silicon copper sheets.
Countermeasures such as slowing down the pickling speed or using mechanical grinding in combination with pickling have been taken to prevent scraping, but there is a problem in that productivity is significantly reduced.
このような問題のために、高珪素鋼の粒界酸化を防止す
るためには、熱間圧延鋼板におけろスケールの発生をで
きる限り抑制することが必要と考えられ、従って、スラ
ブ加熱炉の雰囲気を非酸化性にずろか、また（Ｊ、スラ
ブ加熱温度を低くするか等によって、粗圧延板の酸化を
極力抑制し、粒界酸化層を通常の酸洗方法により除去す
ることができろ程度に薄くすることも考えられろ。Because of these problems, in order to prevent grain boundary oxidation in high-silicon steel, it is considered necessary to suppress the occurrence of scale in hot rolled steel sheets as much as possible. It is possible to suppress the oxidation of the rough rolled sheet as much as possible by making the atmosphere non-oxidizing or by lowering the slab heating temperature, and to remove the grain boundary oxidation layer by the usual pickling method. You could also consider making it slightly thinner.
しかし、この方法においては、スラブ加熱のコストが高
くなったり、また、熱間圧延にお（ｊろ荷重が極めて高
くなる等の問題があり、かつ、充分冷間圧延鋼板の粒界
酸化防止方法を第１の発明とし、
（２） Ｃ０．０５〜０．２５ｗｔ％、Ｓ ｉ ０．
５〜３０ｗｔ％、Ｍｎ ０．５−３．０ｗｔ％
を含有し、さらに、
Ｎｂ ０．０２〜０．１０ｗｔ％、Ｔｉ ０．０１−０
．ｌ０ｗｔ％、Ｐ ０．０３〜０．ｌ０ｗｔ％
の内から選んだ１種または２種以」二
を含有し、残部Ｆｅおよび不可避不純物からなる鋼を均
熱処理後、熱間圧延を行い、熱間圧延終了後から巻き取
るまでの時間の１／３の時間以内に７００℃以下の温度
に冷却した後、５５０℃以下の温度において巻き取るこ
とを特徴とする高強度冷間圧延鋼板の粒界酸化防止方法
を第２の発明とする２つの発明よりなるものである。However, in this method, there are problems such as the cost of heating the slab being high and the load during hot rolling being extremely high. is the first invention, (2) C0.05-0.25wt%, Si 0.
5-30 wt%, Mn 0.5-3.0 wt%, and further Nb 0.02-0.10 wt%, Ti 0.01-0
．． l0wt%, P 0.03-0. A steel containing one or more selected from 10 wt% and the remainder Fe and unavoidable impurities is hot rolled after soaking, and the time from the end of hot rolling to winding is A second invention provides a method for preventing intergranular oxidation of a high-strength cold-rolled steel sheet, which comprises cooling to a temperature of 700°C or less within 1/3 of the time and then winding at a temperature of 550°C or less. This invention consists of two inventions.
本発明に係る高強度冷間圧延鋼板の粒界酸化防止方法に
ついて、以下詳細に説明する。The method for preventing grain boundary oxidation of high-strength cold-rolled steel sheets according to the present invention will be described in detail below.
本発明に係る高強度冷間圧延鋼板の粒界酸化防止方法に
おいて、本発明者は高珪素鋼の熱間圧延後の巻き取り温
度を低くすることが粒界酸化を防止ずろためには有効な
ことを知見したが、巻き取り温度を低くして粒界酸化を
防止するためには、３００℃程度のという低１）巻き取
り温度にずろ必要があり、そのため熱間圧延板の形状が
極めて悪くなり、さらに、熱間圧延板の強度が非常に高
くなるので、冷間圧延に際して負荷が高くなるという問
題がある。この低温巻き取り利を冷間圧延を行なう前に
焼鈍して軟化させてから、冷間圧延時の負荷を軽減する
技術があるが、］二程か煩雑となって生産性が悪くなり
、生産コストが高くなる。従って、本発明者は第１図り
に示すように、熱間圧延を終了してから巻き取るまでの
時間を特定することによって、即ち、具体的には熱間圧
延の最終スタンドを出た後、巻き取るきての時間をｔ。In the method for preventing grain boundary oxidation of high-strength cold-rolled steel sheets according to the present invention, the inventor has found that lowering the coiling temperature after hot rolling of high-silicon steel is effective in preventing grain boundary oxidation. However, in order to lower the winding temperature to prevent grain boundary oxidation, it is necessary to lower the winding temperature to around 300°C, which results in extremely poor shape of the hot rolled sheet. Furthermore, since the strength of the hot-rolled plate becomes very high, there is a problem that the load increases during cold rolling. There is a technology to reduce the load during cold rolling by annealing and softening this low-temperature winding before cold rolling, but this is complicated and reduces productivity. Cost increases. Therefore, as shown in the first diagram, by specifying the time from the end of hot rolling to the time of winding, specifically, after exiting the final stand of hot rolling, The time it takes to wind up is t.
とじた時に］／３ｔｏ以内の時間に７００℃以下の温度
に急冷して、巻き取る而のγ−α変態量を多くして巻き
取り後の変態復熱を小さくし、かつ、５５０℃以下の温
度で巻き取ることにより、粒界酸化を防止ずろのである
。] / 3 to 500°C or less to increase the amount of γ-α transformation during winding to reduce the transformation recuperation after winding, and Winding at high temperatures prevents grain boundary oxidation.
このような本発明に係る高強度冷間圧延鋼板のよって、
Ｓ１含有量は０５〜３０ｗ［％とする。Due to the high strength cold rolled steel sheet according to the present invention,
The S1 content is 05 to 30 w[%.
ＭｎｔＪ変態組織強化には欠くことができない元素であ
り、含有量が０．５ｗｔ％未満ではこの効果が得られず
、また、３．０ｗｔ％を越えて含有されると鋼板の延性
が劣化する。よって、Ｍｎ含有量は０５〜３．０ｗｔ％
とオる。It is an essential element for strengthening the MntJ transformation structure, and if the content is less than 0.5 wt%, this effect cannot be obtained, and if the content exceeds 3.0 wt%, the ductility of the steel sheet will deteriorate. Therefore, the Mn content is 05 to 3.0 wt%
That's it.
Ｎｂは析出強化、細粒化強化を得ろためには必要な元素
であり、含有量が０．０２ｗｔ％未満ではこのような効
果が少なく、また、０．１０ｗｔ％を越えて含有される
と効果が飽和するばかりか、延性が劣化する。よって、
ＮｂＭ有量は００２〜０．１．０ｗｔ％とする。Nb is a necessary element to obtain precipitation strengthening and grain refinement strengthening, and if the content is less than 0.02 wt%, this effect will be small, and if the content exceeds 0.10 wt%, it will not be effective. Not only does this saturate, but the ductility deteriorates. Therefore,
The amount of NbM is 0.02 to 0.1.0 wt%.
Ｔ１はＮｂと同様に析出強化、細粒化強化に必要な元素
であり、含有量が０．０１．ｗｔ％未満で（Ｊこのよう
な効果は少なく、また、０．１０ｗｔ％を越えて含有さ
れると鋼板の延性が劣化する。よって、Ｔｉ含有量は０
０１〜０．］Ｏｗｔ％とする。Like Nb, T1 is an element necessary for precipitation strengthening and grain refinement strengthening, and the content is 0.01. If the Ti content is less than 0.10 wt%, the ductility of the steel sheet will deteriorate.
01~0. ]Owt%.
ＰはＳｉと同様にフェライトを固溶強化し、高延性高強
度銅板の製造に有効な元素であり、含有量か０．０３ｗ
ｔ％未満ではこの効果は少なく、また、粒界酸化防止方
法（」、従来の熱間圧延高張力鋼板においては（第１図
Ｂ、Ｃの場合）、巻き取る直前において急冷し、巻き取
り後に主として変態させるとは異なっており、熱間圧延
終了後に直ちに冷却して、巻き取る前に極力変態させろ
ことにより、巻き取り後の変態復熱を小さくすることに
より、粒界酸化を防止するものである。Like Si, P is an element that solid-solution strengthens ferrite and is effective in manufacturing high-ductility, high-strength copper plates, and the content is 0.03w.
If it is less than t%, this effect is small, and in the conventional hot-rolled high-strength steel sheet (cases B and C in Figure 1), the grain boundary oxidation prevention method (in the case of Fig. 1 B and C) involves rapid cooling immediately before winding, and This is different from mainly transforming the material, and by cooling it immediately after hot rolling and allowing as much transformation as possible before winding, grain boundary oxidation is prevented by reducing the transformation recuperation after winding. be.
次に、本発明に係る高強度冷間圧延鋼板の粒界酸化防止
方法において、使用する綱の含有成分および含有割合に
ついて説明する。Next, in the method for preventing intergranular oxidation of high-strength cold-rolled steel sheets according to the present invention, the components and content ratios of the steel used will be explained.
Ｃは変態組織強化により高強度鋼板とするために有効な
元素であり、含有量が０．０５ｗｔ％未満ではこのよう
な効果は少なく、また、０．２５ｗｔ％を越えて含有さ
れるとスポット溶接性が劣化する。よって、Ｃ含有ｆｆ
１ｌｊ： ０．０５−０．２５ｗｔ％とする。C is an effective element for making high-strength steel sheets by strengthening the transformation structure. If the content is less than 0.05 wt%, this effect is small, and if the content exceeds 0.25 wt%, spot welding may occur. sex deteriorates. Therefore, C-containing ff
1lj: 0.05-0.25wt%.
Ｓｌは粒界酸化に有害であるが、鋼の延性向上には有効
であることから、高延性高強度鋼板に（」必要な元素で
あり、含有量が０５１％未嵩で（Ｊ粒界酸化は生じない
ので問題はなく、また、：ＬＯｗｔ％を越えて含有され
ろと冷間加工性が劣化ずろ。Although Sl is harmful to grain boundary oxidation, it is effective in improving the ductility of steel, so it is a necessary element for high ductility and high strength steel sheets. Since this does not occur, there is no problem, and if the content exceeds LOwt%, cold workability will deteriorate.
０．１．０ｗｔ％を越えて含有されるとスポット溶接性
が劣化オろ。よって、Ｐ含有量（」： ０．０３〜０．
１０ｗｔ％とする。If the content exceeds 0.1.0 wt%, spot weldability will deteriorate. Therefore, the P content ('': 0.03-0.
It is set to 10wt%.
本発明に係る高強度冷間圧延鋼板の粒界酸化防止方法の
熱処理について説明ずろ。The heat treatment of the method for preventing grain boundary oxidation of high-strength cold-rolled steel sheets according to the present invention will now be explained.
均熱処理後熱間圧延を行なう場合に、熱間圧延終了後か
ら巻き取るまでの時間の１／３以内に７００℃以下の温
度に冷却するのであるが、即ち、熱間圧延最終スタンド
を出た後、直ちに７００℃以下に急冷を行な９つない場
合には、第２図に示すようにγ−α変態に非常に長時間
を必要とし、そのため、巻き取り後の変態による復熱が
著しくなって粒界酸化を防止することができな円第２図
において使用した鋼は、０．１７ｗｔ％Ｃ−］、５ｗｔ
％ｓ１２、Ｏｗｔ％Ｍｎ−Ｆｅ残部てある。When hot rolling is performed after soaking, the material is cooled to a temperature of 700°C or less within 1/3 of the time from the end of hot rolling to the time of winding. If the material is not immediately quenched to 700°C or less after winding, it will take a very long time for the γ-α transformation, as shown in Figure 2, and as a result, the reheating caused by the transformation after winding will be significant. The steel used in Fig. 2, in which grain boundary oxidation cannot be prevented by
%s12, Owt%Mn-Fe balance.
しかし、熱間圧延最終スタンドを出た後、巻き取るまで
の時間ｔ。の＋／３ｔｏの時間以内に７００℃以下の温
度に急冷した場合には、巻き取るまでの間にγ−α変態
が促進され、巻き取り後の変態によろ復熱を小さくケろ
ことかてき、従−１て、巻き取り温度が５５０℃以下で
あっても充分に粒界酸化を防止することが可能となり、
さらに、熱間圧延板は強度が低くなり形状も良好となる
。However, the time t from leaving the final hot rolling stand to winding up is t. If it is rapidly cooled to a temperature of 700°C or less within +/3 to of time, the γ-α transformation will be promoted before winding, and the transformation after winding will reduce the heat regeneration. Therefore, it is possible to sufficiently prevent grain boundary oxidation even if the winding temperature is 550°C or lower,
Furthermore, the hot-rolled plate has lower strength and a better shape.
［実 施 例］
本発明に係る高強度冷間圧延鋼板の粒界酸化防止方法の
実施例を説明する。[Example] An example of the method for preventing grain boundary oxidation of a high-strength cold-rolled steel sheet according to the present invention will be described.
実施例
第１表に示す含有成分および含有割合の鋼を転炉におい
て溶製し、連続鋳造によりスラブを製造してから、第２
表に示す条件により、スラブを通常の雰囲気において加
熱し、６００ｍ／ｍｉｎの速度で２ 、５ ｍｍの厚さ
に熱間圧延を行ない、最終スタンドを出た後、１８秒後
に巻きとって酸洗後、１．２ｍｍの厚さまで冷間圧延を
行ない、次いで、連続焼鈍による熱処理を行なった。Example Steel having the components and content ratios shown in Table 1 is melted in a converter, and a slab is manufactured by continuous casting.
According to the conditions shown in the table, the slab was heated in a normal atmosphere and hot-rolled at a speed of 600 m/min to a thickness of 2.5 mm, and after leaving the final stand, it was rolled up and pickled 18 seconds later. Thereafter, cold rolling was performed to a thickness of 1.2 mm, and then heat treatment by continuous annealing was performed.
第２表に結果を示す。Table 2 shows the results.
１〜４は何れも高珪素の同一成分の綱種である。All of Nos. 1 to 4 are high silicon species with the same composition.
比較＠１は］／３ｔＱ時間、即ち、最終スタンドを出て
から６秒後の温度が７５０℃と高いため、５００℃の温
度で巻き取りを行なったにも拘わらず、変態復熱により
巻き取り後温度が上昇し、粒界酸化が生している。Comparison @1 is ]/3tQ time, that is, the temperature 6 seconds after exiting the final stand is as high as 750°C, so even though the winding was performed at a temperature of 500°C, the winding was delayed due to transformation recuperation. The post-temperature increases and grain boundary oxidation occurs.
比較鋼２は巻き取り温度を鋼１よりも低温としたため、
粒界酸化は防止オろことができたが、熱間圧延板の形状
が悪く、さらに、その強度が高いために冷間圧延におｉ
−＋る生産性を著しく低下する。Comparative Steel 2 had a lower winding temperature than Steel 1, so
Grain boundary oxidation could be prevented, but the shape of the hot-rolled sheet was poor and its strength was high, making cold rolling difficult.
- Significantly lower productivity.
本発明鋼３は＋ ／ ３ ｔｏ待時間お（Ｊる温度、巻
き取り温度共に適正な範囲内（本発明に係る高強度冷間
圧延銅板の粒界酸化防止方法の範囲内）であるため、熱
間圧延後の鋼板の形状も良好であり、粒界酸化は発生し
ていない。Invention Steel 3 has a waiting time of +/3 to (J temperature and coiling temperature are both within appropriate ranges (within the range of the method for preventing grain boundary oxidation of high-strength cold-rolled copper sheets according to the present invention). The shape of the steel sheet after hot rolling was also good, and grain boundary oxidation did not occur.
本発明鋼４は本発明ｗＡ３よりスラブ加熱温度が高く、
−次スケール厚さも厚いが、最終スタンドを出てからの
冷却方法、巻き取り条件が適性であるため、熱間圧延板
の形状が良好で、粒界酸化も発生していない。Inventive steel 4 has a higher slab heating temperature than inventive wA3,
Although the second scale thickness is large, the cooling method and winding conditions after leaving the final stand are appropriate, so the shape of the hot rolled sheet is good and grain boundary oxidation does not occur.
比較＠５は＋／３ｔｏ時間における温度が８００℃と高
いので、熱間圧延板の強度か高く、形状が悪く、粒界酸
化が発生している。Comparison @5 has a high temperature of 800° C. at +/3 to time, so the strength of the hot rolled sheet is high, the shape is poor, and grain boundary oxidation occurs.
比較鋼７（１本発明鋼６と同一の鋼であるが、巻き取り
温度が高いので粒界酸化が発生している。Comparative Steel 7 (1) This is the same steel as Invention Steel 6, but grain boundary oxidation occurs because the coiling temperature is high.
第３図は本発明鋼６、第４図は比較鋼７のそれぞれの顕
微鏡写真を示しているが、本発明鋼６は粒界酸化は認め
られないが、比較鋼７には粒界酸化が認められる。Figure 3 shows micrographs of Inventive Steel 6, and Figure 4 shows micrographs of Comparative Steel 7. Inventive Steel 6 shows no grain boundary oxidation, but Comparative Steel 7 does. Is recognized.
比較鋼８は低Ｓｉ鋼であるため、本発明に係る高強度冷
間圧延鋼板の粒界酸化防止方法の範囲外の条件で熱間圧
延を行なっても粒界酸化は発生していない。Since Comparative Steel 8 is a low-Si steel, grain boundary oxidation does not occur even when hot rolling is performed under conditions outside the range of the method for preventing grain boundary oxidation of a high-strength cold rolled steel sheet according to the present invention.
第
表
−ｌター
ｇ ８ｇ ８ ｇ ８ ８ ８ ８０■旬トＯり
寸ＣＱｃ−＜
つ。 ’ｄ”Ｆ−各
［発明の効果］
以上詳細に説明したように、本発明に係る高強度冷間圧
延鋼板の粒界酸化防止方法は上記の構成であるから、高
珪素鋼板であっても粒界酸化の発生が認められず、酸洗
も通常の鋼板と同様な速度で行なうことができ、生産性
の低下を招来することなく製造することができ、さらに
、熱間圧延ままの材料にも適用することができろという
優れた効果を有するものである。Table - 1 g 8 g 8 g 8 8 8 80 'd'F-Each [Effects of the Invention] As explained in detail above, since the method for preventing grain boundary oxidation of a high-strength cold-rolled steel sheet according to the present invention has the above configuration, even if the high-silicon steel sheet is No grain boundary oxidation is observed, pickling can be carried out at the same speed as ordinary steel sheets, and production is possible without reducing productivity. It has such excellent effects that it can also be applied.
第１図は熱間圧延終了後から巻き取るまでの鋼板の温度
変化を示す図、第２図は熱間圧延終了後の変態曲線図、
第３図本発明鋼６の通常の酸洗後の表層部の顕微鏡写真
、第４図は比較鋼７の通常の酸洗後の表層部の顕微鏡写
真で♂うろ。
ω ト ■
り。Ｖ■くFigure 1 is a diagram showing the temperature change of the steel plate from the end of hot rolling until it is rolled up, Figure 2 is a diagram of the transformation curve after the end of hot rolling,
Fig. 3 is a microscopic photograph of the surface layer of the invention steel 6 after normal pickling, and Fig. 4 is a microscopic photo of the surface layer of comparative steel 7 after normal pickling. ω ト■ri. V■ku
Claims (2)
０ｗｔ％、Ｍｎ０．５〜３．０ｗｔ％ を含有し、残部Ｆｅおよび不可避不純物からなる鋼を均
熱処理後、熱間圧延を行い、熱間圧延終了後から巻き取
るまでの時間の１／３の時間以内に７００℃以下の温度
に冷却した後、５５０℃以下の温度において巻き取るこ
とを特徴とする高強度冷間圧延綱板の粒界酸化防止方法
。(1) C0.05-0.25wt%, Si0.5-3.
After soaking a steel containing 0 wt%, Mn 0.5 to 3.0 wt%, and the balance consisting of Fe and unavoidable impurities, hot rolling is performed, and the steel is heated for 1/3 of the time from the end of hot rolling to winding. A method for preventing intergranular oxidation of a high-strength cold-rolled steel sheet, the method comprising cooling to a temperature of 700°C or less within an hour and then winding at a temperature of 550°C or less.
ｗｔ％、Ｍｎ０．５〜３０ｗｔ％ を含有し、さらに、 Ｎｂ０．０２〜０．１０ｗｔ％、Ｔｉ０．０１〜０．１
０ｗｔ％、Ｐ０．０３〜０．１０ｗｔ％ の内から選んだ１種または２種以上 を含有し、残部Ｆｅおよび不可避不純物からなる鋼を均
熱処理後、熱間圧延を行い、熱間圧延終了後から巻き取
るまでの時間の１／３の時間以内に７００℃以下の温度
に冷却した後、５５０℃以下の温度において巻き取るこ
とを特徴とする高強度冷間圧延鋼板の粒界酸化防止方法
。(2) C0.05-0.25wt%, Si0.5-30
wt%, Mn0.5-30wt%, and further contains Nb0.02-0.10wt%, Ti0.01-0.1
0 wt%, P0.03 to 0.10 wt%, and the remainder consists of Fe and unavoidable impurities. After soaking, hot rolling is carried out, and after the hot rolling is completed. 1. A method for preventing intergranular oxidation of a high-strength cold-rolled steel sheet, the method comprising cooling to a temperature of 700° C. or lower within 1/3 of the time from 1 to 1/3 of the time from 1/3 to winding, and then winding at a temperature of 550° C. or lower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63201765A JPH0250908A (en) | 1988-08-12 | 1988-08-12 | Method for preventing intergranular oxidation of high-strength cold-rolled steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63201765A JPH0250908A (en) | 1988-08-12 | 1988-08-12 | Method for preventing intergranular oxidation of high-strength cold-rolled steel sheet |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0250908A true JPH0250908A (en) | 1990-02-20 |
Family
ID=16446567
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63201765A Pending JPH0250908A (en) | 1988-08-12 | 1988-08-12 | Method for preventing intergranular oxidation of high-strength cold-rolled steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0250908A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011184741A (en) * | 2010-03-09 | 2011-09-22 | Kobe Steel Ltd | HIGHLY Si-CONTAINING STEEL SHEET HAVING EXCELLENT SURFACE PROPERTY, AND METHOD FOR PRODUCING THE SAME |
| CN103290308A (en) * | 2012-02-27 | 2013-09-11 | 株式会社神户制钢所 | High-strength cold-rolled steel plate and manufacturing method thereof |
| KR20170122723A (en) | 2015-03-23 | 2017-11-06 | 신닛테츠스미킨 카부시키카이샤 | Hot-rolled steel sheet, manufacturing method thereof, and method of manufacturing cold-rolled steel sheet |
-
1988
- 1988-08-12 JP JP63201765A patent/JPH0250908A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011184741A (en) * | 2010-03-09 | 2011-09-22 | Kobe Steel Ltd | HIGHLY Si-CONTAINING STEEL SHEET HAVING EXCELLENT SURFACE PROPERTY, AND METHOD FOR PRODUCING THE SAME |
| CN103290308A (en) * | 2012-02-27 | 2013-09-11 | 株式会社神户制钢所 | High-strength cold-rolled steel plate and manufacturing method thereof |
| KR20170122723A (en) | 2015-03-23 | 2017-11-06 | 신닛테츠스미킨 카부시키카이샤 | Hot-rolled steel sheet, manufacturing method thereof, and method of manufacturing cold-rolled steel sheet |
| US11066720B2 (en) | 2015-03-23 | 2021-07-20 | Nippon Steel Corporation | Hot-rolled steel sheet and manufacturing method thereof, and manufacturing method of cold-rolled steel sheet |
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