JPS63290222A - Manufacture of hot-dipped steel sheet excellent in deep drawability by thin cc - Google Patents
Manufacture of hot-dipped steel sheet excellent in deep drawability by thin ccInfo
- Publication number
- JPS63290222A JPS63290222A JP12261787A JP12261787A JPS63290222A JP S63290222 A JPS63290222 A JP S63290222A JP 12261787 A JP12261787 A JP 12261787A JP 12261787 A JP12261787 A JP 12261787A JP S63290222 A JPS63290222 A JP S63290222A
- Authority
- JP
- Japan
- Prior art keywords
- hot
- steel
- less
- steel sheet
- deep drawability
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 46
- 239000010959 steel Substances 0.000 title claims abstract description 46
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 238000007747 plating Methods 0.000 claims abstract description 27
- 238000001953 recrystallisation Methods 0.000 claims abstract description 9
- 238000007711 solidification Methods 0.000 claims abstract description 7
- 230000008023 solidification Effects 0.000 claims abstract description 7
- 238000000137 annealing Methods 0.000 claims abstract description 6
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 6
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 229910052799 carbon Inorganic materials 0.000 claims abstract 2
- 238000005096 rolling process Methods 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 238000001816 cooling Methods 0.000 abstract description 35
- 238000005098 hot rolling Methods 0.000 abstract description 11
- 239000000203 mixture Substances 0.000 abstract description 10
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 2
- 239000000853 adhesive Substances 0.000 abstract 1
- 230000001070 adhesive effect Effects 0.000 abstract 1
- 238000007598 dipping method Methods 0.000 abstract 1
- 230000003746 surface roughness Effects 0.000 description 11
- 206010013786 Dry skin Diseases 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 238000012360 testing method Methods 0.000 description 8
- 238000005097 cold rolling Methods 0.000 description 7
- 238000012545 processing Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 229910001208 Crucible steel Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000009749 continuous casting Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000009863 impact test Methods 0.000 description 2
- 239000004615 ingredient Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000003679 aging effect Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000010960 cold rolled steel Substances 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000005554 pickling Methods 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 238000009849 vacuum degassing Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Continuous Casting (AREA)
- Coating With Molten Metal (AREA)
- 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、薄ＣＣによる深絞り性の優れた溶融メッキ鋼
板をコスト安く製造する方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a hot-dip plated steel sheet with excellent deep drawability using thin CC at low cost.
（従来技術）
従来、深絞り性の優れた溶融メッキ鋼板は、限定された
成分の鋼を２００＋＋＋ｍ〜２５０隔厚の連続鋳造スラ
ブまたは分塊スラブとし、これを加熱し、２〜６１まで
熱間圧延し、酸洗、冷延、連続溶融メッキ工程を経て製
造されている。この場会、熱間圧延を２００〜２５０鵡
から２〜６順厚まで圧延するため、強大な圧延工場を必
要とし、その消費エネルギーも多大なものとなる。最近
、上記の欠点を克服する方法として、鋳片厚みを製品厚
みにできるだけ近すけようという試がなされている。(Prior art) Conventionally, hot-dip plated steel sheets with excellent deep drawability have been produced by forming steel with limited ingredients into continuous casting slabs or blooming slabs with a thickness of 200 + + + m to 250 m, which is then heated and hot-dipped to a temperature of 2 to 61 mm. It is manufactured through rolling, pickling, cold rolling, and continuous hot-dip plating processes. In this case, since hot rolling is carried out from 200 to 250 mm to a normal thickness of 2 to 6, a powerful rolling mill is required, and its energy consumption is also large. Recently, attempts have been made to make the slab thickness as close as possible to the product thickness as a way to overcome the above-mentioned drawbacks.
具体的な方法として、熱間圧延を行わないで、直接冷延
素材を連続鋳造により製造するものと、熱間圧延工程の
中閾厚みの鋳片を製造し、熱同圧延を簡省略するものが
ある。Specific methods include one in which cold-rolled material is directly produced by continuous casting without hot rolling, and one in which slabs with a medium threshold thickness are produced in the hot rolling process and hot rolling is simplified. There is.
前者の方法は工程を省略する点では優れているが、製造
された鋼板は硬質で加工性が劣り、製品の結晶粒が細か
いにもかかわらず、加工時に肌荒れが発生し、加工用と
しては用いられない。しかも、メッキの密着性が従来工
程で製造されたものより劣るという問題点がある。The former method is superior in that it omits a process, but the manufactured steel sheet is hard and has poor workability, and even though the product has fine grains, the surface becomes rough during processing, making it unsuitable for processing. I can't. Moreover, there is a problem in that the adhesion of the plating is inferior to those manufactured using conventional processes.
（本発明が解決しようとする問題点）
この発明は前述の従来技術における問題点を解決し、深
絞り性が優れ、加工時に肌荒れが発生しない。しかも、
メッキ密着性の優れた溶融メッキ鋼板を熱延工程を省略
した製造方法で提供することを目的としてなされた。(Problems to be Solved by the Present Invention) The present invention solves the problems in the prior art described above, has excellent deep drawability, and does not cause surface roughness during processing. Moreover,
The purpose was to provide a hot-dip plated steel sheet with excellent plating adhesion using a manufacturing method that omitted the hot rolling process.
（問題点を解決するだめの手段）
本発明者等は、鋼成分、鋳片４与、凝固後の熱履歴を検
討した結果、鋼成分を限定し、凝固後の特定の温度範囲
の冷却速度のコントロールにより熱延を完全に省略し、
深絞り性の優れ、しかも加工時に肌荒れが発生しなくメ
ッキ密着性が優れた溶融メッキ鋼板を製造できることを
知見した。(Another means to solve the problem) As a result of studying the steel composition, the amount of slab 4, and the thermal history after solidification, the inventors limited the steel composition and determined the cooling rate within a specific temperature range after solidification. Hot rolling can be completely omitted by controlling
It was discovered that it is possible to produce a hot-dip plated steel sheet that has excellent deep drawability, does not cause surface roughness during processing, and has excellent plating adhesion.
本発明の要旨とするところは、重量％でＣ；０゜ｏｏｓ
ｏｑ６以下、Ｍｎ ； １．０ ％以下、ｓｔ；ｏ、３
％以下、ｐ；ｏ、ｏｓ％以下、Ｓ；０．０２０％以下、
Ａε；０．００５〜０．０７０ チ、 Ｂ；０．０００
２〜０゜００５０チ、Ｔｉ；０．０８０チ以下、Ｎｂ
； ０．０５０チ以下で、しかもＴ１≧３．４２ Ｎ−
）−１，５８−１−４０を含有し、残部が鉄および不可
避的不純物からなる溶鋼を１０論以下の薄鋳帯とし、凝
固後９５０ ’Ｃ〜７５０°Ｃ間をＶ−Ｃ，／ｓ以上で
冷却し、巻き取り後、冷間圧延し鋼板の温度が、再結晶
温度以上、Ａ１点以下で再結晶焼鈍し、引き続いて溶融
メッキすることを特徴とする深絞り性の優れた溶融メッ
キ鋼板の製造法にある。ただしＶＣ’Ｃ／ｅ ）＝５．
０ＸＩＯ−’／（Ｎｂ（％）×Ｂ（％））
まず、本発明の深絞り用溶融メッキ鋼板の成分限定につ
いて述べる。The gist of the present invention is that C; 0゜oos in weight%
oq 6 or less, Mn; 1.0% or less, st; o, 3
% or less, p; o, os% or less, S; 0.020% or less,
Aε; 0.005 to 0.070 Chi, B; 0.000
2~0゜0050 inch, Ti; 0.080 inch or less, Nb
; 0.050 inch or less, and T1≧3.42 N-
)-1,58-1-40, with the remainder consisting of iron and unavoidable impurities, the molten steel is made into a thin cast band of 10 or less, and after solidification, it is heated between 950'C and 750°C by V-C,/s. After cooling and coiling, the cold-rolled steel sheet is recrystallized and annealed at a temperature higher than the recrystallization temperature and lower than the A1 point, followed by hot-dip plating with excellent deep drawability. It is in the manufacturing method of steel plates. However, VC'C/e)=5.
0XIO-'/(Nb (%) x B (%)) First, the component limitations of the hot-dip plated steel sheet for deep drawing of the present invention will be described.
Ｃは、従来から少なければ少ないほど溶融メッキ鋼板の
深絞り性が良好になることが知られている。しかし、そ
の含有量を０．００１０％以下にするには溶製が極めて
困難になる。一方Ｃ量が０．０８０％を越えて、含有さ
せると加工性が劣化し、多くの炭窒化物形成元素を添加
する必要があり、コスト上昇になるばかりでなく再結晶
温度が高くなり、高温焼鈍を必要とする。加えて鋼板の
加工性も劣化することから、Ｃ含有量は０．００１０〜
ｏ、ｏｏｓ％に限定した。好ましい範囲は０．００１０
〜０．００７０チである。It has been conventionally known that the smaller the amount of C, the better the deep drawability of the hot-dip plated steel sheet. However, reducing the content to 0.0010% or less makes melting extremely difficult. On the other hand, if the amount of C exceeds 0.080%, the workability deteriorates and it is necessary to add many carbonitride-forming elements, which not only increases the cost but also increases the recrystallization temperature and increases the temperature. Requires annealing. In addition, since the workability of the steel plate also deteriorates, the C content should be set at 0.0010~
It was limited to o, oos%. The preferred range is 0.0010
~0.0070chi.
Ｓｉ、Ｍｎ、Ｐは鋼板の高強度化に有効な元素である。Si, Mn, and P are elements effective in increasing the strength of steel sheets.
本発明では軟質溶融メッキ鋼板および高強度溶融メッキ
鋼板をも製造目的とするので、Ｓｉ は０．００５〜０
．０７０Ｍｎは０．０５〜１．０％、Ｐは０．００３〜
０．１０％の成分範囲とする。Since the purpose of the present invention is to manufacture soft hot-dip plated steel sheets and high-strength hot-dip plated steel sheets, Si is 0.005 to 0.
．． 070Mn is 0.05~1.0%, P is 0.003~
The component range is 0.10%.
即ち高強度溶融メッキ鋼板を製造する場合は、これ等の
元素はＳｉ；０．３０％、Ｍｎ；１．０％、Ｐ；０．１
０％を上限とする。Ｓｌは多すぎると、メッキ密着性が
劣化し、Ｍｎは多くなると極低Ｃの鋼を溶製するのが困
難になり、Ｐは多すぎると、スポット浴接性が劣化する
と共に、粒界にＰが偏析し、プレス加工時に二次加工性
が劣化する。これ等の理由により、Ｓｉ、Ｍｎ、Ｐの上
限を規定した。That is, when manufacturing high-strength hot-dip plated steel sheets, these elements are Si: 0.30%, Mn: 1.0%, P: 0.1
The upper limit is 0%. Too much Sl will deteriorate plating adhesion, too much Mn will make it difficult to produce steel with extremely low C, and too much P will cause poor spot bath weldability and damage to grain boundaries. P segregates and secondary workability deteriorates during press working. For these reasons, the upper limits of Si, Mn, and P were defined.
なお軟質溶融メッキ鋼板を製造するときは、Ｍｎ；０．
０５〜０．５０係、Ｓｌ；０．００５〜０．０２％。In addition, when manufacturing a soft hot-dip plated steel sheet, Mn; 0.
05-0.50 ratio, Sl; 0.005-0.02%.
Ｐｒｏ、００１〜０．０２０％にすることが好ましい。Pro, preferably 001 to 0.020%.
Ｍｎが０．５０％を越えると硬質になり、延性に富んだ
鋼板を製造できない。同様の理由から、Ｓｌは０゜０５
０チ以下、Ｐは０．０２％以下にすることが好ましい。If Mn exceeds 0.50%, the steel plate becomes hard and cannot produce a highly ductile steel plate. For the same reason, Sl is 0°05
It is preferable that P be 0.02% or less.
Ｓは熱間脆性の原因となる元素であることが良く知られ
ている。しかし、本発明では熱間圧延を行わないので熱
間脆性での問題はないが、鋳片を直接冷延するさいにＳ
ｌが多いと、冷延時に耳割れが発生し易くなり、加えて
鋼板が硬質化するので軟質鋼板を製造する場合は、０．
０２％以下とする必要がある。It is well known that S is an element that causes hot embrittlement. However, since hot rolling is not performed in the present invention, there is no problem with hot brittleness, but when directly cold rolling the slab, S
If there is too much l, edge cracking will easily occur during cold rolling, and in addition, the steel plate will become hard, so when manufacturing a soft steel plate, 0.
It is necessary to keep it below 0.02%.
ＭはＴ１の酸化物による冷延板の表面疵の発生を防止す
ると共に、メッキ密着不良を防止するため、酸可溶Ａｔ
としてｏ、ｏｏｓ％以上とする必要がある。M is acid-soluble At to prevent the occurrence of surface flaws on the cold-rolled sheet due to the oxide of T1 and to prevent poor plating adhesion.
It is necessary to set it to o, oos% or more.
一方、高くなりすぎると、アルミナ系の介在物が増え、
冷延板の表面疵が逆に増加し、メツキネ良が増えるので
、酸可溶Ｍとして０．０７％を上限とする。好ましい範
囲は０．０１５〜０．０５０％である。On the other hand, if the height is too high, alumina-based inclusions will increase,
On the contrary, the surface flaws of the cold-rolled sheet increase and the roughness increases, so the upper limit of acid-soluble M is set at 0.07%. The preferred range is 0.015% to 0.050%.
ＮはＴ１によりＴｉＮとして固定されるが、Ｎが多すぎ
るとＴ１添加量が増加しコスト上昇および加工性が劣化
するので少ないほうが好ましい。したがってＮの上限は
０．ＯＯ’７０％である。下限は特に限定しないが現在
の技術で達成可能な０．００１０チを包含する。N is fixed as TiN by T1, but if there is too much N, the amount of T1 added increases, resulting in an increase in cost and deterioration of workability, so a smaller amount is preferable. Therefore, the upper limit of N is 0. OO' is 70%. The lower limit is not particularly limited, but includes 0.0010 inches, which is achievable with current technology.
Ｔ１は床絞り用溶融メッキ鋼板として必要な深絞り性、
延性、非時効性を確保するため、Ｔ１量１．５８−１−
３．４２Ｎ＋４０を満足する必要がある。一方、Ｔ１量
が多くなるほど加工性が優れるが、ｏ、ｏｅｏ％を越え
るとその効果が飽和し、これ以上の添加はコストの上昇
をまねくので経済的でないと同時に、鋳造性を悪くする
、またＴ１酸化物による表面疵に起因するメツキネ良が
増加する。T1 has the deep drawability required as a hot-dip plated steel sheet for floor drawing.
In order to ensure ductility and non-aging properties, the T1 amount is 1.58-1-
It is necessary to satisfy 3.42N+40. On the other hand, the greater the amount of T1, the better the workability, but if it exceeds o, oeo%, the effect is saturated, and adding more than this will increase the cost, which is not economical, and at the same time will worsen the castability. Scratchiness due to surface flaws caused by T1 oxide increases.
ＢおよびＮｂは鋳片の冷却速度とともに本発明の重要な
構成要件である。この限定理由を知見した実験事実につ
いて述べる。B and Nb are important components of the present invention, along with the cooling rate of the slab. We will discuss the experimental facts that revealed the reason for this limitation.
ｃ；ｏ、ｏｏｌｏ〜０．００７０％、Ｓｉ；０．０１％
。c; o, oolo ~ 0.0070%, Si; 0.01%
.
Ｍｎ ； ０．１〜０．３％、 Ｔｉ ； ０．０４３
〜０．０８０％。Mn: 0.1-0.3%, Ti: 0.043
~0.080%.
Ｐ；０．０１２％、へ１；ｏ、ｏ１ｓ〜０．０５３チ、
Ｎ；０，００２５〜０．００３９チの鋼にＢ；０．００
０１〜Ｑ、００４５％、Ｎｂ；０．００１〜ｏ、ｏ７ｏ
％に変化させた溶鋼を４．０ｆｉの鋳片とし、凝固後た
だちに冷却速度を変え６００℃まで冷却し、６００℃で
一時間保定し徐冷した。この鋳片を０．８Ｍまで冷延し
、連続溶融Ｚｎメッキを行った。溶融Ｚｎメッキの条件
は８２５℃Ｘ ｌ ｍｉｎの再結晶焼鈍を行い、引き続
いてＺｎメッキをおこない、合金化処理を行った。P;0.012%, 1;o, o1s~0.053chi,
N; 0.0025 to 0.0039 steel; B; 0.00
01~Q, 0045%, Nb; 0.001~o, o7o
% of the molten steel was made into a slab of 4.0fi, and immediately after solidification, the cooling rate was changed to cool it to 600°C, and the temperature was maintained at 600°C for 1 hour for slow cooling. This slab was cold rolled to 0.8M and continuously hot-dip Zn plated. The conditions for hot-dip Zn plating were recrystallization annealing at 825°C x l min, followed by Zn plating and alloying treatment.
この鋼板の肌荒れ試験およびメッキ密着性試験を行った
。肌荒れ試験はバルジで一定高さまで張り出し、その時
の肌荒れの程度を３段階で評価した。This steel plate was subjected to a roughening test and a plating adhesion test. In the skin roughness test, the bulge was extended to a certain height, and the degree of skin roughness at that time was evaluated on a three-grade scale.
評点１は肌荒れが皆無、評点２は肌荒れが若干ある、評
点３は肌荒れが発生とした。メッキ密着性はポールイン
パクトテストを行い、さらに変形部の外側にセロテープ
をはり、その後引きはがして、メッキの剥離の程度によ
って決める５段階評価法を用いた。評点ｌはまったく剥
離が無い場合、評点２はごく僅かに剥離があった場合、
評点３は明らかに剥離があった場合、評点４は変形部の
円周方向に全面にわたって剥離が認められる場合、評点
５は変形の少ない箇所からも剥離が認められる場合で評
価した。A rating of 1 means no rough skin, a rating of 2 means some rough skin, and a rating of 3 means rough skin occurs. The adhesion of the plating was determined by a pole impact test, and a 5-grade evaluation method was used in which Sellotape was applied to the outside of the deformed area and then peeled off to determine the degree of peeling of the plating. Rating 1 means that there is no peeling at all, and rating 2 means that there is very little peeling.
A rating of 3 was given when there was obvious peeling, a rating of 4 was given when peeling was observed over the entire circumferential direction of the deformed portion, and a score of 5 was given when peeling was found even from areas with little deformation.
Ｎｂ量とＢ量と冷却速度が５０℃／ｓ以上の鋼板の肌荒
れ評点の関係を第一図に示した。図中の線は数多くテス
トの肌荒れ評点の範囲を示し、図中の数字はその範囲の
肌荒れ評点を示す。第一図かられかるようにＮｂ、Ｂを
複合添加し、Ｂは０，０００３チ以上、Ｎｂは０．００
３％以上添加することにより肌荒れが回避されることが
わみる。一方、上限は第一図から分かる様に一定以上の
添加で効果が飽和することが分かる。そのためＢは０．
００５０％をＮｂは０．０５０１％にそれぞれ上限を特
定した。Figure 1 shows the relationship between the amount of Nb, the amount of B, and the roughness score of a steel plate with a cooling rate of 50° C./s or more. The lines in the figure indicate the range of skin roughness scores of numerous tests, and the numbers in the figure indicate the rough skin scores in that range. As shown in Figure 1, Nb and B are added in combination, B is 0,0003 or more, Nb is 0.00
It can be seen that by adding 3% or more, skin roughness can be avoided. On the other hand, as can be seen from Figure 1, the effect is saturated when the upper limit is added above a certain level. Therefore, B is 0.
The upper limits were specified as 0.0050% and 0.0501% for Nb.
なお第一図の鋼板の結晶粒度は８．０〜９．８の範囲で
めった。次にＮｔ） Ｘ Ｂ と冷却速度と肌荒れ性
の関係を第二図に示した。図中の破線は数多くテストの
肌荒れ評点の範囲を示し、実線はＶＸＢＸＮｂ＝ ５．
ＯＸ １０−’ ＠示し、図中の数字はその範囲の肌荒
れ評点を示す。第二図から明らかなようにＮｂ×Ｂと冷
却速度に肌荒れ注が影響されることがわかる。すなわち
、冷却速度が速い時はＮｂ Ｘ Ｂ量が少なくても肌荒
れが発生しない、一方冷却速度が遅い時はＮｂＸＢ量を
充分に多くすれば肌荒れを防止することが出来る。すな
わち、鋳片の冷却速度；’／（’Ｃ／８）≧５． ｏ
Ｘ Ｉ Ｏ−’／ （Ｎｂ（％）ｘ Ｂ（＠）を満足す
れば肌荒れを防止することができる。The grain size of the steel plate shown in Figure 1 was set within the range of 8.0 to 9.8. Next, Figure 2 shows the relationship between Nt)XB, cooling rate, and skin roughness. The broken lines in the figure indicate the range of skin roughness scores of many tests, and the solid line indicates VXBXNb=5.
OX 10-'@ is shown, and the numbers in the figure show rough skin scores in that range. As is clear from FIG. 2, it can be seen that rough skin is affected by Nb×B and the cooling rate. That is, when the cooling rate is fast, rough skin does not occur even if the amount of NbXB is small, while when the cooling rate is slow, rough skin can be prevented by increasing the amount of NbXB sufficiently. That is, the cooling rate of the slab;'/('C/8)≧5. o
If X I O-'/ (Nb (%) x B (@) is satisfied, rough skin can be prevented.
第三図はＮｂ、Ｂとメッキ密着性の関係を示した。Figure 3 shows the relationship between Nb, B and plating adhesion.
図中の数字はメッキ密着性の評点を示した。第三図から
分かるようにメッキ密着性はＮｂ量が０．００５チ以上
で、Ｂがｏ、ｏｏｏ３％以上でメッキ密着性が優れてい
ることが分る。この事実に基すき肌荒れが生じなくしか
もメッキ密着性が優れる鋼板を得る条件としてＮｂ、Ｂ
量および冷却速度とその関係を規定した。The numbers in the figure indicate the plating adhesion scores. As can be seen from Figure 3, the plating adhesion is excellent when the Nb content is 0.005% or more and the B content is o, ooo 3% or more. Based on this fact, Nb, B, and
The amount and cooling rate and their relationship were defined.
次に鋳片の冷却速度を５０ ”Ｃ／ｓと一定にし冷却の
温度範囲を変えた鋳片を０．８ｍｍまで冷延し、８２５
℃Ｘ １ ｍｉｎの再結晶焼鈍を行い、１．０％のスキ
ンパス後、第一図と同様の肌荒れ試験および材質試験を
おこなった。その結果を第四図に示した。Next, the slab was cooled to a thickness of 0.8 mm by keeping the cooling rate constant at 50"C/s and varying the cooling temperature range.
Recrystallization annealing was performed for 1 min at ℃, and after a 1.0% skin pass, the same rough skin test and material test as in Figure 1 were performed. The results are shown in Figure 4.
他の製造条件のうち鋼成分はＣｏｏ、００３５％。Among other manufacturing conditions, the steel composition is Coo, 0035%.
Ｓｉ ；０．００９％、 Ｍｎ；０．２１％、
Ｐ；０．００９％、ｓ；ｏ、ｏｏａ ％、ｕ ； ｏ
、５１％、 Ｎ ； ０．００２７チ、Ｔｉ；Ｑ、
０５５ チ、 Ｎｂ；ｏ、ｏ ｌ ５チ、Ｂｏｏ
。Si; 0.009%, Mn; 0.21%,
P; 0.009%, s; o, ooa%, u; o
, 51%, N; 0.0027 Chi, Ti; Q,
055 Chi, Nb; o, o l 5 Chi, Boo
.
００７チ、鋳片厚みは４．０咽である。なお、第四図の
○印は冷却開始温度；９５０℃以上で冷却終了温度；７
５０℃以下のものであり、Δ印は冷却開始温度；９５０
℃以下かあるいは冷却終了温度；７５０℃以上のもので
ある。第四図から分かるように肌荒れ性を良好とするた
めには冷却開始温度が９５０°Ｃ以上で冷却終了温度は
７５０℃以下である。一方加工性の点からは冷却終了温
度を６００℃以上にすることが好ましい。この事実に基
すき鋳片の冷却開始温度を９５０℃以上および冷却終了
温度を７５０℃以下と規定した。007 mm, and the slab thickness is 4.0 mm. In addition, the ○ mark in Figure 4 indicates the cooling start temperature; 950°C or higher is the cooling end temperature; 7
The temperature is 50℃ or less, and the Δ mark is the cooling start temperature; 950
℃ or lower, or the cooling end temperature is 750℃ or higher. As can be seen from FIG. 4, in order to improve the skin roughness, the cooling start temperature is 950°C or higher and the cooling end temperature is 750°C or lower. On the other hand, from the viewpoint of workability, it is preferable that the cooling end temperature be 600° C. or higher. Based on this fact, the cooling start temperature of the slab was defined as 950°C or higher and the cooling end temperature as 750°C or lower.
このような成分の鋼を転炉あるいは電気炉で必要に応じ
て真空脱ガス処理により浴製し鋳鋼帯とする。鋳鋼帯の
厚みはｌＯｗ＋以下とすることが好ましい。その理由は
鋳片の冷却速度の確保、製品の板厚から深絞りが良好と
なる冷延率を確保するためである。この鋳鋼帯は９５０
℃〜７５０℃間をｙ ”（：／ｓ以上で冷却し、巻き取
る。なおＶ（’Ｃ／ｓ ） ＝ ５． ＯＸ Ｉ Ｏ−
’／ （Ｎｂ（％）×Ｂ（％））である。ただし、鋳片
の形状矯正のため５０チ以下の圧延をおこなっても本発
明の特徴を損なわない。巻き取り温度は７５０℃以下で
出来る限り高い方が好ましい。Steel having such components is bath-formed into a cast steel strip by vacuum degassing treatment in a converter or electric furnace as required. The thickness of the cast steel strip is preferably lOw+ or less. The reason for this is to ensure the cooling rate of the slab and the cold rolling rate that will allow good deep drawing based on the thickness of the product. This cast steel strip is 950
℃~750℃ at y''(:/s or more, and wind it up. Note that V('C/s) = 5. OX IO-
'/(Nb(%)×B(%)). However, even if the slab is rolled to 50 inches or less to correct its shape, the features of the present invention will not be impaired. The winding temperature is preferably 750° C. or lower and as high as possible.
巻き取られたコイルは冷却後、脱スケールして、冷却圧
延する。冷間圧延する温度は圧延中に回復あるいは再結
晶しなければ何度でもよい。本発明の鋼成分では、圧延
中に回復あるいは再結晶しない温度は６００℃以下であ
る。冷延率は５０〜９５゜チである。この冷延板は連続
式の溶融メッキが施され製品に供される。After the coil is cooled, it is descaled and cold-rolled. The cold rolling temperature may be any number of times as long as there is no recovery or recrystallization during rolling. In the steel composition of the present invention, the temperature at which recovery or recrystallization does not occur during rolling is 600°C or lower. The cold rolling rate is 50 to 95 degrees. This cold-rolled sheet is subjected to continuous hot-dip plating and then used as a product.
（実施例）
第１表に示す成分および製造条件で解融メッキ鋼板を製
造し、その材質特性および鋼板の肌荒れ性、メッキ密着
性を調べた。肌荒れ試験はバルジで一定高さまで張り出
し、その時の肌荒れ程度を３段階で評価した。評点１は
肌荒れが皆無、評点２は肌荒れが若干ある、評点３は肌
荒れが発生とした。二次加工性は絞り比２．０の絞りカ
ップを０℃で押し広げをおこない、縦割れが無いものを
０、縦割れが生じたものを×で表した。メッキ密着性は
ポールインパクトテストを行い、さらに変形部の外側に
セロテープをはり、その後引きはがして、メッキの剥離
の程度によって決める５段階評価法を用いた。評点ｌは
まったく剥離がない場合、評点２はごく僅かに剥離があ
った場合、評点３は明らかに剥離があった場合、評点４
は変形部の円周方向に全面にわたって剥離が認められる
場合、評点５は変形の少ない箇所からも剥離が認められ
る場合で評価した。(Example) Hot-dip plated steel sheets were manufactured using the ingredients and manufacturing conditions shown in Table 1, and the material properties, surface roughness, and plating adhesion of the steel sheets were investigated. In the skin roughness test, the bulge was extended to a certain height, and the degree of skin roughness at that time was evaluated in three stages. A rating of 1 means no rough skin, a rating of 2 means some rough skin, and a rating of 3 means rough skin occurs. For secondary workability, a drawing cup with a drawing ratio of 2.0 was expanded at 0°C, and samples with no vertical cracks were expressed as 0, and samples with longitudinal cracks were expressed as x. The adhesion of the plating was determined by a pole impact test, and a 5-grade evaluation method was used in which Sellotape was applied to the outside of the deformed area and then peeled off to determine the degree of peeling of the plating. Rating 1 is when there is no peeling at all, Rating 2 is when there is very slight peeling, Rating 3 is when there is obvious peeling, and Rating 4 is when there is obvious peeling.
A rating of 5 was given when peeling was observed over the entire circumferential direction of the deformed portion, and a rating of 5 was given when peeling was observed even from areas with little deformation.
第１表の結果から、本発明の方法で製造したものは、深
絞り性と相関あるｒ値が高く、肌荒れ性、メッキ密着性
も優れていることが分かる。また二次加工性も優れてい
ることがわかる。なおコイルＩ＠２は形状矯正のため２
０チの熱延をじた実施例であり、コイルＮ１５，６．７
はノーイテンの実施例でるる。成分的には本発明の範囲
内でも、鋳片の冷却速度が本発明範囲外であるコイルＮ
［Ｌ ８は肌荒れ性が劣るのみならず加工性も悪くなっ
ている。From the results in Table 1, it can be seen that the products produced by the method of the present invention have a high r value, which correlates with deep drawability, and are also excellent in surface roughness resistance and plating adhesion. It can also be seen that the secondary processability is excellent. Coil I@2 is 2 for shape correction.
This is an example of hot rolling of 0 inch, coil N15, 6.7
is an example of Noiten. Even though the composition is within the scope of the present invention, the cooling rate of the slab is outside the scope of the present invention.
[L8 not only has poor surface roughness but also poor workability.
一方製造条件的には本発明の範囲内でも、成分的に本発
明範囲外であるコイルＮ１９，１０は肌荒れ性が劣るの
みならず加工性も悪くなっている。コイルＮＩＬ１１は
成分的にも本発明範囲外で鋳片の冷却速度も本発明範囲
外である、材質特性、肌荒れ性ともに劣ていることがわ
かる。以上の実施例から分かるように鋼成分、鋳片の冷
却速度が密接不可分の関係により深絞り性が優れ、しか
も加工時に肌荒れが発生しなくメッキ密着性が優れた溶
融メッキ鋼板が製造可能であることがわかる。On the other hand, even though the manufacturing conditions are within the scope of the present invention, coils Nos. 19 and 10, which are outside the scope of the present invention in terms of components, not only have poor surface roughness but also have poor workability. It can be seen that the composition of the coil NIL11 is outside the range of the present invention, the cooling rate of the slab is also outside the range of the present invention, and both material properties and surface roughness are inferior. As can be seen from the above examples, the close and inseparable relationship between the steel composition and the cooling rate of the slab makes it possible to produce hot-dip coated steel sheets that have excellent deep drawability, do not cause surface roughness during processing, and have excellent plating adhesion. I understand that.
（発明の効果）
本発明に従えば、上記実施例からも明かなように、限定
成分の鋼を連続鋳造して薄鋳片とし、鋳片の冷却過程の
コントロールにより、従来工程の如く、強大な熱間圧延
機列による熱間圧延を完全に省略しても深絞り性が優れ
、しかも加工時に肌荒れが発生しないメッキ密着性が潰
れた溶融メッキ鋼板が製造可能となる。かくして工程の
省略にともなう、省エネルギー、コストの大幅な低減を
可能とすることから、本発明は産業上著しく有用な発明
である。(Effects of the Invention) According to the present invention, as is clear from the above embodiments, steel with a limited composition is continuously cast into a thin slab, and by controlling the cooling process of the slab, it is possible to achieve strong strength as in the conventional process. Even if hot rolling by a row of hot rolling mills is completely omitted, it is possible to produce a hot-dip plated steel sheet that has excellent deep drawability and has good plating adhesion without causing surface roughness during processing. In this way, the present invention is an industrially extremely useful invention because it enables energy saving and significant cost reduction due to the omission of steps.
第一図はＮｂ、Ｂ量とメッキ板の肌荒れ性の関係を示す
図。第二図はＮｂＸＢ、鋳片の冷却速度とメッキ板の肌
荒れ性の関係を示す図。第三図はＮｂ。
Ｂとメッキ密着性の関係を示す図。第四図は鋳片の冷却
速度； ｖ （’Ｃ／ ｓ ）≧５．ＯＸ Ｉ Ｏ−’
／ （ｎｂ（％）ｘＢ（％））を満足する冷却速度で
の冷却開始および冷却終了温度と冷延・焼鈍後の肌荒れ
性およびｒ値、伸びの関係を示す図。Figure 1 is a diagram showing the relationship between the amounts of Nb and B and the surface roughness of the plated plate. Figure 2 is a diagram showing the relationship between the cooling rate of NbXB slabs and the surface roughness of plated plates. The third figure is Nb. A diagram showing the relationship between B and plating adhesion. Figure 4 shows the cooling rate of the slab; v ('C/s)≧5. OX I O-'
/ (nb (%) x B (%)) A diagram showing the relationship between the cooling start and cooling end temperatures at a cooling rate that satisfies (nb (%) x B (%)), the roughness of the surface after cold rolling and annealing, the r value, and the elongation.
Claims (1)
、Ｓｉ；０．３％以下、Ｐ；０．０８％以下、Ｓ；０．
０２０％以下、Ａｌ；０．００５〜０．０７０％、Ｂ；
０．０００３〜０．００５０％、Ｔｉ；０．０８０％以
下、Ｎｂ；０．０５０％以下で、しかもＴｉ≧３．４２
Ｎ＋１．５Ｓ＋４Ｃを含有し、残部が鉄および不可避的
不純物からなる溶鋼を１０ｍｍ以下の薄鋳帯とし、凝固
後９５０℃〜７５０℃間をＶ℃／ｓ以上で冷却し、巻き
取り後、冷間圧延し、連続メッキラインで鋼板の温度を
再結晶温度以上、Ａ＿３点以下で再結晶焼鈍を行い、引
き続いて連続的に溶融メッキすることを特徴とする深絞
り性の優れた溶融メッキ鋼板の製造法。ただし、Ｖ（℃
／ｓ）＝５．０×１０＾−＾４／｛Ｎｂ（％）×Ｂ（％
）｝In weight%, C: 0.0080% or less, Mn: 1.0% or less, Si: 0.3% or less, P: 0.08% or less, S: 0.
020% or less, Al; 0.005 to 0.070%, B;
0.0003 to 0.0050%, Ti: 0.080% or less, Nb: 0.050% or less, and Ti≧3.42
Molten steel containing N+1.5S+4C, with the balance consisting of iron and unavoidable impurities is made into a thin cast band of 10 mm or less, and after solidification, it is cooled between 950°C and 750°C at V°C/s or more, and after being rolled up, it is cold rolled. Production of a hot-dip plated steel sheet with excellent deep drawability, characterized by rolling, recrystallizing annealing the steel sheet at a temperature above the recrystallization temperature and below the A_3 point on a continuous plating line, and then continuously hot-dip plating. Law. However, V(℃
/s)=5.0×10^-^4/{Nb(%)×B(%
)}
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62122617A JP2525180B2 (en) | 1987-05-21 | 1987-05-21 | Method for producing hot-dip galvanized steel sheet with excellent deep drawability by thin CC |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62122617A JP2525180B2 (en) | 1987-05-21 | 1987-05-21 | Method for producing hot-dip galvanized steel sheet with excellent deep drawability by thin CC |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63290222A true JPS63290222A (en) | 1988-11-28 |
| JP2525180B2 JP2525180B2 (en) | 1996-08-14 |
Family
ID=14840389
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62122617A Expired - Lifetime JP2525180B2 (en) | 1987-05-21 | 1987-05-21 | Method for producing hot-dip galvanized steel sheet with excellent deep drawability by thin CC |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2525180B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02163346A (en) * | 1988-12-15 | 1990-06-22 | Nisshin Steel Co Ltd | Hot dip galvanized cold rolled high-tensile steel sheet excellent in press formability and its production |
| JP2004195522A (en) * | 2002-12-19 | 2004-07-15 | Nippon Steel Corp | Low carbon thin-walled cast steel piece and low carbon steel sheet obtained by twin drum type continuous casting process, and method for manufacturing the same |
| JP2008274338A (en) * | 2007-04-27 | 2008-11-13 | Sumitomo Metal Ind Ltd | Steel sheet superior in surface properties, hot-dip galvanized steel sheet, and method for continuously casting slab for use in manufacturing steel sheet |
-
1987
- 1987-05-21 JP JP62122617A patent/JP2525180B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02163346A (en) * | 1988-12-15 | 1990-06-22 | Nisshin Steel Co Ltd | Hot dip galvanized cold rolled high-tensile steel sheet excellent in press formability and its production |
| JP2004195522A (en) * | 2002-12-19 | 2004-07-15 | Nippon Steel Corp | Low carbon thin-walled cast steel piece and low carbon steel sheet obtained by twin drum type continuous casting process, and method for manufacturing the same |
| JP2008274338A (en) * | 2007-04-27 | 2008-11-13 | Sumitomo Metal Ind Ltd | Steel sheet superior in surface properties, hot-dip galvanized steel sheet, and method for continuously casting slab for use in manufacturing steel sheet |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2525180B2 (en) | 1996-08-14 |
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