JP3234642B2 - High tensile cold rolled steel sheet for deep drawing and method for producing the same - Google Patents
High tensile cold rolled steel sheet for deep drawing and method for producing the sameInfo
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- JP3234642B2 JP3234642B2 JP21148392A JP21148392A JP3234642B2 JP 3234642 B2 JP3234642 B2 JP 3234642B2 JP 21148392 A JP21148392 A JP 21148392A JP 21148392 A JP21148392 A JP 21148392A JP 3234642 B2 JP3234642 B2 JP 3234642B2
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Description
【０００１】[0001]
【産業上の利用分野】この発明は、高強度で、プレス成
形性に優れる深絞り加工用高張力冷延鋼板とその製造方
法を提案するものである。この発明にかかる冷延鋼板
は、適宜表面処理やプレス加工をしたのち、例えば自動
車や家電製品などに使用され、場合によってはスポット
溶接して用いられるものであり、特にそれらに要求され
る成形性と強度を同時に付与することができるため、鋼
板の薄肉化、ひいては軽量化が達成できるものであっ
て、具体的には経済性に優れた引張強さが38kgf/mm2 以
上で、ランクフォード値すなわち平均ｒ値が1.8 以上の
冷延鋼板が求められている。BACKGROUND OF THE INVENTION The present invention proposes a high-strength cold-rolled steel sheet for deep drawing having high strength and excellent press formability, and a method for producing the same. The cold-rolled steel sheet according to the present invention is used, for example, for automobiles and home electric appliances after being subjected to surface treatment and press working as appropriate, and is sometimes used by spot welding in some cases. And strength at the same time, it is possible to achieve a reduction in the thickness of the steel sheet and, consequently, a reduction in weight.Specifically, an economical tensile strength of 38 kgf / mm 2 or more, and a Rankford value That is, a cold rolled steel sheet having an average r value of 1.8 or more is required.
【０００２】[0002]
【従来の技術】従来より、製鋼段階で十分に脱炭処理を
施して極低炭素とし、さらに鋼中の固溶Ｃや固溶ＮをTi
などを含有させてこれらの炭窒化物として析出させＣや
Ｎを固定した鋼をベースとして、これにSi、Mn及びＰな
どを固溶させ、強度を高めた高張力冷延鋼板については
多くの提案がなされている。2. Description of the Related Art Conventionally, decarburization has been sufficiently performed at the steel making stage to obtain extremely low carbon, and solid solution C and solid solution N in steel have been reduced to Ti.
High tensile strength cold-rolled steel sheets with increased strength based on steel containing C and N fixed by precipitating them as carbonitrides and containing Si, Mn and P in solid solution A proposal has been made.
【０００３】例えば、特開昭63−190141号公報の成形性
の良好な高張力冷延鋼板とその製法においては、上記極
低炭素Ti添加鋼に多量のMn及びＰを添加した冷延鋼板が
開示されている。この場合においては、適量のMn及びＰ
を添加することにより、焼鈍後少量の固溶Ｃが残存し、
これがｒ値を著しく向上させ、しかも、粒界に存在する
固溶Ｃのため二次加工脆性が効果的に防止されるとし、
さらに粒界強化のため必要に応じてＢを添加してもよい
としている。しかしながら、Siを無添加としてＰを添加
した場合スポット溶接性が劣化するという問題がある。[0003] For example, in Japanese Patent Application Laid-Open No. 63-190141, a high-tensile cold-rolled steel sheet having good formability and a method for producing the same include a cold-rolled steel sheet obtained by adding a large amount of Mn and P to the ultra-low carbon Ti-added steel. It has been disclosed. In this case, appropriate amounts of Mn and P
, A small amount of solute C remains after annealing,
This remarkably improves the r value, and furthermore, the secondary solution embrittlement is effectively prevented due to the solid solution C existing at the grain boundary,
Further, B may be added as necessary for strengthening the grain boundaries. However, when P is added without adding Si, there is a problem that spot weldability deteriorates.
【０００４】このほかにも、上記極低炭素鋼に、Si、Mn
及びＰの固溶強化成分を複合添加した冷延鋼板について
いくつかの開示がなされている。しかしながら、これら
のSi、Mn及びＰの添加は単に固溶強化のためであり、個
々の成分の平均ｒ値への影響は明らかにされているもの
の、高い深絞り性を有するこれら固溶成分間の複合添加
のバランスについては未だ解明されていないのが現状で
ある。[0004] In addition, Si, Mn,
And cold-rolled steel sheets to which a solid solution strengthening component of P is added in combination. However, the addition of Si, Mn, and P is merely for solid solution strengthening, and although the influence on the average r value of each component has been clarified, the addition between these solid solution components having high deep drawability has been described. At present, it is not clear yet the balance of the compound addition of the above.
【０００５】[0005]
【発明が解決しようとする課題】この発明は、固溶Ｃ及
び固溶Ｎを固定するためのTi添加に加えて固溶Ｃのより
確実な固定を行うためNbを添加し、さらに二次加工脆性
の抑制のためにＢを添加した、極低炭素Ti、Nb、Ｂ複合
添加鋼をベースにし、これをSiを含む低コストの合金添
加で、しかも通常の連続焼鈍で目標とする引張強さ38kg
f/mm2 以上、平均ｒ値1.8 以上の耐二次加工脆性に優れ
る高張力冷延鋼板とその製造方法を提案することを目的
とする。SUMMARY OF THE INVENTION The present invention is based on the object of the present invention, in addition to the addition of Ti for fixing solid solution C and solid solution N, in addition to the addition of Nb for more securely fixing solid solution C, Based on ultra-low carbon Ti, Nb, and B composite added steel with B added to suppress brittleness, this is the target tensile strength with the addition of a low-cost alloy containing Si and ordinary continuous annealing. 38 kg
It is an object of the present invention to propose a high-tensile cold-rolled steel sheet having f / mm 2 or more and an average r value of 1.8 or more and having excellent secondary work brittleness resistance, and a method for producing the same.
【０００６】[0006]
【課題を解決するための手段】発明者らは、かかる目的
達成のため、上記の極低炭素Ti、Nb、Ｂ複合添加鋼に注
目し、鋭意研究を進めてきた。その結果、極低炭素Ti、
Nb、Ｂ複合添加鋼において、Si及びＰの添加量にたいし
て、Mnの添加量を適当なバランスに保たせることによ
り、Nb添加によるより確実な固溶Ｃの固定化とあいまっ
て高い平均ｒ値が得られることを新たに知見した。Means for Solving the Problems In order to achieve the above object, the present inventors have focused on the ultra-low carbon Ti, Nb, and B-added steels and have been diligently conducting research. As a result, extremely low carbon Ti,
In the Nb and B composite-added steel, by maintaining the addition amount of Mn with respect to the addition amount of Si and P, a high average r value is obtained in combination with the more reliable fixation of solid solution C by the addition of Nb. It was newly found that it could be obtained.
【０００７】これは、Mn添加による熱延母板の細粒化に
起因していて、このため焼鈍後の平均ｒ値の向上に有効
な（１１１）集合組織が発達するためである。一般に固
溶強化成分を単独に添加した場合、Ｐ及びSiについては
平均ｒ値への影響は少なく、むしろ平均ｒ値を上昇させ
る成分であるのに対して、Mnは平均ｒ値を大きく劣化さ
せることが知られている。しかしながら、複合添加した
場合には、Si及びＰのみでは、変態点が急激に上昇して
しまい、圧延条件及び焼鈍条件を規制する必要があっ
た。このため、変態点を下げる成分の添加が必要となっ
てきた。この変態点温度を下げる成分としては、Mn、N
i、Cu及びCrなどが挙げられるが、低コストでしかも有
効に変態点温度を低下させるためには、Mnの添加が有効
となる。しかしMnの添加量が多すぎると、低温変態相が
あらわれ熱延板を高強度にするとともに、焼鈍材の深絞
り性を大きく劣化させる。[0007] This is due to the refinement of the grain size of the hot-rolled base plate by the addition of Mn, and therefore the (111) texture effective for improving the average r value after annealing develops. In general, when a solid solution strengthening component is added alone, P and Si have little effect on the average r value, but rather increase the average r value, whereas Mn greatly deteriorates the average r value. It is known. However, when a composite is added, the transformation point rises rapidly only with Si and P, and it is necessary to regulate the rolling conditions and the annealing conditions. For this reason, it has become necessary to add a component that lowers the transformation point. Components that lower the transformation point temperature include Mn and N
Although i, Cu and Cr can be mentioned, addition of Mn is effective for lowering the transformation point temperature effectively at low cost. However, if the added amount of Mn is too large, a low-temperature transformation phase appears to make the hot-rolled sheet high in strength and greatly deteriorates the deep drawability of the annealed material.
【０００８】したがって、この発明は、Si及びＰの添加
量に応じた量のMnを添加することにより、熱延板を焼入
れ組織とすることなくフェライト組織とし、しかも、適
度なSi、Mn及びＰのバランスを保たせることによりフェ
ライト粒径を微細にし、Nb添加によるより確実な固溶Ｃ
の固定とあいまって高い平均ｒ値が得られるようにした
ものである。Therefore, the present invention provides a ferritic structure without adding a quenched structure to a hot-rolled sheet by adding Mn in an amount corresponding to the added amounts of Si and P, and furthermore, a moderate amount of Si, Mn and P Ferrite grain size by keeping the balance of C, more reliable solid solution C by Nb addition
Is fixed so that a high average r value can be obtained.
【０００９】すなわち、この発明の要旨は、 Ｃ：0.001 wt％以上、0.005 wt％以下、 Si：0.2 wt％以上、1.0 wt％以下、 Mn：0.5 wt％以上、2.0 wt％以下、 Ti：0.01wt％以上、0.2 wt％以下、 Nb：0.001 wt％以上、0.02wt％以下、 Ｂ：0.0002wt％以上、0.005 wt％以下、 Ｐ：0.05wt％以上、0.15wt％以下、 Ｓ：0.02wt％以下、 sol Al：0.1 wt％以下及び Ｎ：0.005 wt％以下 を含んで、上記Si、Mn及びＰの含有量が、That is, the gist of the present invention is as follows: C: 0.001 wt% or more, 0.005 wt% or less, Si: 0.2 wt% or more, 1.0 wt% or less, Mn: 0.5 wt% or more, 2.0 wt% or less, Ti: 0.01 wt% or more, 0.2 wt% or less, Nb: 0.001 wt% or more, 0.02 wt% or less, B: 0.0002 wt% or more, 0.005 wt% or less, P: 0.05 wt% or more, 0.15 wt% or less, S: 0.02 wt% Hereinafter, the content of Si, Mn, and P including sol Al: 0.1 wt% or less and N: 0.005 wt% or less,
【数３】 0.2 ≦（Si（wt％）＋Ｐ（wt％））／Mn（wt％）≦1.0 の関係を満たし、残部は鉄及び不可避的不純物の組成か
らなることを特徴とする深絞り加工用高張力冷延鋼板で
あり、Deep drawing characterized by satisfying the following relationship: 0.2 ≦ (Si (wt%) + P (wt%)) / Mn (wt%) ≦ 1.0, with the balance being composed of iron and unavoidable impurities. High-strength cold-rolled steel sheet for
【００１０】上記成分組成になる鋼スラブを素材とし
て、Ar3 点（℃）以上、Ar3 点（℃）＋100 ℃以下の圧
延仕上げ温度範囲で熱間圧延を終了し、650 ℃以下の温
度で巻取ったのち、冷間圧延を行い、その後750 ℃以上
の温度で連続焼鈍を施すことを特徴とする深絞り加工用
高張力冷延鋼板の製造方法である。Using a steel slab having the above-mentioned composition as a raw material, hot rolling is completed at a rolling finish temperature range of not less than Ar 3 points (° C.) and not more than Ar 3 points (° C.) + 100 ° C., and the temperature is not more than 650 ° C. This is a method for producing a high-tensile cold-rolled steel sheet for deep drawing, which comprises performing cold rolling after winding, followed by continuous annealing at a temperature of 750 ° C. or more.
【００１１】[0011]
【作用】この発明における鋼の化学成分組成の限定理由
について述べる。 Ｃ：0.001 〜0.005 wt％ Ｃは、再結晶時に固溶Ｃが多量に残存した場合、平均ｒ
値を大きく劣化させる。また、固溶Ｃを固定させるTi、
NbもＣ含有量に応じて添加する必要があるためＣ含有量
はできるだけ低い方がよく、許容できる上限を0.005 wt
％とする。一方その下限は低いほどよいが、現在の製鋼
技術から0.001 wt％を下限とする。The reasons for limiting the chemical composition of steel in the present invention will be described. C: 0.001 to 0.005 wt% C is an average of r when a large amount of solid solution C remains during recrystallization.
Significantly degrade the value. Also, Ti for fixing solid solution C,
Since Nb also needs to be added according to the C content, the C content is preferably as low as possible, and the allowable upper limit is 0.005 wt.
%. On the other hand, the lower limit is better as low as possible, but the lower limit is 0.001 wt% based on current steelmaking technology.
【００１２】Si：0.2 〜1.0 wt％ Siは、固溶強化能が大きく、平均ｒ値を劣化させないた
め固溶強化成分として最適でありスポット溶接性の劣化
を抑制する。その効果の発現には最低でも0.2wt％を含
有させる必要がある。しかしながら、含有量が1.0 wt％
を超えると表面処理性が悪くなる。したがってその含有
量は、0.2 wt％以上、1.0 wt％以下とする。Si: 0.2 to 1.0 wt% Si has a large solid solution strengthening ability and does not deteriorate the average r value, so it is optimal as a solid solution strengthening component and suppresses deterioration of spot weldability. It is necessary to contain at least 0.2% by weight to achieve the effect. However, the content is 1.0 wt%
If it exceeds 300, the surface treatment properties will deteriorate. Therefore, the content is set to 0.2 wt% or more and 1.0 wt% or less.
【００１３】Mn：0.5 〜2.0 wt％ Mnは、この発明において重要な成分である。MnはSiやＰ
とは異なり、変態点を下げる成分であるためこれを有効
に活用することにより、熱延板の粒径を極めて細かくす
ることができる。この熱延板の細粒化は、結晶粒界から
（１１１）集合組織が発達するため、平均ｒ値の向上に
非常に有効である。その効果は含有量が0.5 wt％以上で
得られる。一方Mn自体は平均ｒ値を劣化させる成分であ
るため、多量に含有させることは有害であり、その含有
量が2.0 wt％超えでは低温変態相が現れやすくなってフ
ェライト組織でなくなり、平均ｒ値を大きく劣化させ
る。したがってその含有量は、0.5 wt％以上、2.0 wt％
以下とする。Mn: 0.5 to 2.0 wt% Mn is an important component in the present invention. Mn is Si or P
Unlike this, since it is a component that lowers the transformation point, by effectively utilizing it, the particle size of the hot-rolled sheet can be made extremely fine. This grain refinement of the hot-rolled sheet is very effective in improving the average r value because the (111) texture develops from the crystal grain boundaries. The effect is obtained when the content is 0.5 wt% or more. On the other hand, since Mn itself is a component that deteriorates the average r value, it is harmful to include it in a large amount, and if the content exceeds 2.0 wt%, a low-temperature transformation phase is likely to appear and the ferrite structure is lost. Greatly deteriorates. Therefore, its content is 0.5 wt% or more, 2.0 wt%
The following is assumed.
【００１４】また、上記Siと下記するＰの含有量とMn含
有量とのバランスを、Further, the balance between the content of Si and the content of P described below and the content of Mn is determined as follows.
【数４】 0.2 ≦（Si（wt％）＋Ｐ（wt％））／Mn（wt％）≦１ とすることにより、上記のMnの有効性を発揮することが
できる。これはSiとＰの含有量の和のMn含有量に対する
比が0.2 より小さくなると平均ｒ値が劣化し、反対に1.
0 より多くなると変態点温度が高くなり、熱延板の細粒
化が望めなくなるためである。## EQU4 ## By setting 0.2 ≦ (Si (wt%) + P (wt%)) / Mn (wt%) ≦ 1, the effectiveness of Mn described above can be exhibited. This is because when the ratio of the sum of the Si and P contents to the Mn content is smaller than 0.2, the average r value deteriorates, and conversely 1.
If it exceeds 0, the transformation point temperature becomes high, and it becomes impossible to reduce the grain size of the hot-rolled sheet.
【００１５】Ti：0.01〜0.2 wt％ Tiは、固溶Ｃ、Ｓ及びＮをTiC 、TiS 及びTiN として固
定するために含有させる。その効果は含有量が0.01wt％
未満では十分でなく、0.2 wt％を超えると燐化物が発生
し、伸び及び平均ｒ値を劣化させる。したがってその含
有量は0.01wt％以上、0.2 wt％以下とする。Ti: 0.01-0.2 wt% Ti is contained for fixing solid solution C, S and N as TiC, TiS and TiN. The effect is that the content is 0.01wt%
If the amount is less than 0.2 wt%, phosphide is generated, and the elongation and the average r value are deteriorated. Therefore, its content should be 0.01 wt% or more and 0.2 wt% or less.
【００１６】Nb：0.001 〜0.02wt％ Nbは、Tiと同様にNbC とて固溶Ｃを固定する有効な成分
である。Tiのみでも固溶Ｃの固定はできるが、Nbを複合
添加することにより、より確実にＣを固定することがで
き平均ｒ値を向上させる。その効果は含有量が0.001 wt
％未満では十分でなく、0.02wt％を超えて含有させると
オーステナイト未再結晶状態で熱間圧延することになっ
て、焼鈍材の成形性に悪影響をおよぼす。したがってそ
の含有量は0.001 wt％以上、0.02wt％以下とする。Nb: 0.001 to 0.02 wt% Nb is an effective component for fixing solid solution C as NbC in the same manner as Ti. Although solid solution C can be fixed with Ti alone, C can be fixed more reliably by adding Nb in combination, and the average r value can be improved. The effect is 0.001 wt
% Is not sufficient. If the content exceeds 0.02 wt%, hot rolling is performed in an austenite unrecrystallized state, which adversely affects the formability of the annealed material. Therefore, its content is made 0.001 wt% or more and 0.02 wt% or less.
【００１７】Ｂ：0.0002〜0.005 wt％ Ｂは、二次加工脆性を抑制するために含有させる。とく
にTi、Nbを添加した極低炭素鋼板に固溶強化成分を含有
させると、耐二次加工脆性が悪化するためＢを含有させ
ることを必須とする。その効果は含有量が0.0002wt％以
上で発現するが、0.005 wt％を超えて過剰に含有させる
と、オーステナイトの再結晶を遅らせ熱間圧延時の負荷
が大きくなり、しかも、焼鈍材の材質を劣化させる。し
たがってその含有量は、0.0002wt％以上、0.005 wt％以
下とする。B: 0.0002 to 0.005 wt% B is contained to suppress the brittleness in secondary processing. In particular, when a solid solution strengthening component is added to an ultra-low carbon steel sheet to which Ti and Nb are added, secondary work embrittlement resistance is deteriorated, so that it is essential to add B. The effect is manifested when the content is 0.0002 wt% or more. However, if the content exceeds 0.005 wt%, the recrystallization of austenite is delayed and the load at the time of hot rolling is increased. Deteriorate. Therefore, its content should be 0.0002 wt% or more and 0.005 wt% or less.
【００１８】Ｐ：0.05〜0.15wt％ Ｐは、固溶強化成分として重要な成分であり、その固溶
強化能はSi及びMnにくらべて高く、平均ｒ値を向上させ
る成分でもある。その効果を得るためには0.05wt％以上
含有させる必要があるが、0.15wt％を超えて含有させる
と、粒界に偏析して粒界を脆化させ、さらに凝固時に中
心偏析の原因になる。したがってその含有量は0.05wt％
以上、0.15wt％以下とする。P: 0.05 to 0.15 wt% P is an important component as a solid solution strengthening component, and its solid solution strengthening ability is higher than Si and Mn, and is also a component for improving the average r value. In order to obtain the effect, it is necessary to contain 0.05% by weight or more. However, if it exceeds 0.15% by weight, segregation at the grain boundary causes the grain boundary to become brittle, and further causes central segregation at the time of solidification. . Therefore its content is 0.05wt%
At least 0.15 wt%.
【００１９】Ｓ：0.02wt％以下 Ｓは、平均ｒ値には影響を及ぼさないが、その含有量が
多くなるとMnS などの硫化物が増加し、伸びフランジ性
に代表される局部延性を低下させる原因となるため、そ
の含有量の上限を0.02wt％とする。S: not more than 0.02 wt% S does not affect the average r value, but when its content increases, sulfides such as MnS increase, and the local ductility represented by stretch flangeability decreases. Therefore, the upper limit of the content is set to 0.02 wt%.
【００２０】sol Al：0.1 wt％以下 Alは、脱酸に必要な成分であるが、sol Al含有量が0.1
wt％を超えると脱酸効果が飽和するだけでなく介在物が
増加し、成形性に悪影響をおよぼす。したがってその含
有量は0.1 wt％以下とする。Sol Al: 0.1 wt% or less Al is a component necessary for deoxidation.
If the content exceeds wt%, not only the deoxidizing effect is saturated, but also the number of inclusions increases, which adversely affects the moldability. Therefore, its content should be 0.1 wt% or less.
【００２１】Ｎ：0.005 wt％以下 Ｎは、不可避的に鋼中に混入する不純物成分であるが、
Ti添加によりTiN として固定し成形性を向上させる。し
かしながら、多量のTiN が形成されると加工性の劣化を
まねく。このため許容できる含有量の上限を0.005 wt％
とする。N: 0.005 wt% or less N is an impurity component inevitably mixed into steel.
By adding Ti, it is fixed as TiN to improve formability. However, when a large amount of TiN is formed, workability is deteriorated. Therefore, the upper limit of the allowable content is 0.005 wt%
And
【００２２】次に製造条件について述べる。製鋼、鋳造
条件は常法にしたがって行うことでよい。Next, the manufacturing conditions will be described. Steelmaking and casting conditions may be performed according to a conventional method.
【００２３】 熱間圧延仕上げ温度：Ar3 点〜Ar3 点＋100 ℃ 熱間圧延仕上げ温度は、Ar3 変態点に応じて変化させる
必要がある。Ar3 変態点未満では、二相域圧延となり、
焼鈍材の平均ｒ値に悪影響をおよぼす集合組織が発達し
てしまい好ましくない。一方、Ar3 変態点に対し相対的
に高い温度、すなわち100 ℃を超えて高くなると、熱延
板の粒径が粗くなって、焼鈍時に深絞り性に有効な集合
組織の発達が不十分となるために不適である。したがっ
て熱間圧延仕上げ温度はAr3 点（℃）からAr3 点（℃）
＋100 ℃までとする。Hot rolling finishing temperature: Ar 3 point to Ar 3 point + 100 ° C. The hot rolling finishing temperature needs to be changed according to the Ar 3 transformation point. Below the Ar 3 transformation point, it becomes two-phase zone rolling,
A texture that adversely affects the average r value of the annealed material develops, which is not preferable. On the other hand, when the temperature is relatively high relative to the Ar 3 transformation point, that is, higher than 100 ° C., the grain size of the hot-rolled sheet becomes coarse, and the development of a texture effective for deep drawing during annealing is insufficient. Unsuitable to become. Thus the hot rolling finishing temperature is Ar 3 point (℃) from Ar 3 point (℃)
Up to + 100 ° C.
【００２４】巻取り温度：650 ℃以下 巻取り温度の限定は、この発明のようにTi及びＰが複合
添加されている場合、650 ℃を超えると平均ｒ値が大き
く劣化することを見出したことによるものである。これ
は650 ℃超えの巻取り温度ではTi及びFeの燐化物が熱延
板に多量に析出し、詳細は不明であるが、これが焼鈍材
の平均ｒ値に悪影響をおよぼすためと推測される。した
がって巻取り温度は650 ℃以下とする。Winding temperature: 650 ° C. or less It has been found that the limitation of the winding temperature is that when Ti and P are added in a complex manner as in the present invention, the average r value is greatly deteriorated when the temperature exceeds 650 ° C. It is due to. The reason for this is that at a winding temperature exceeding 650 ° C., a large amount of phosphide of Ti and Fe precipitates on the hot-rolled sheet and details thereof are unknown, but it is presumed that this adversely affects the average r value of the annealed material. Therefore, the winding temperature should be 650 ° C or less.
【００２５】冷間圧延は常法にしたがって行えばよく、
その圧下率も通常常識の範囲でよい。焼鈍は、連続焼鈍
が望ましい。その場合の焼鈍温度は再結晶が完了するよ
うに750 ℃以上とし、その上限はAc1 点温度（℃）＋50
℃とすることが好ましい。The cold rolling may be performed according to a conventional method.
The rolling reduction may be in the range of common sense. Annealing is preferably continuous annealing. In this case, the annealing temperature is set to 750 ° C. or higher so that recrystallization is completed, and the upper limit is Ac 1 point temperature (° C.) + 50.
It is preferably set to ° C.
【００２６】[0026]
【実施例】表１に示す化学成分組成に調製した鋼スラブ
を素材として、これらを熱間圧延してコイルに巻取り、
酸洗後、80％の圧下率で冷間圧延を行って板厚 0.8mmと
し、40秒間のアランダムバス処理による焼鈍を施して得
られた鋼板について引張特性を調査した。EXAMPLES Steel slabs having the chemical composition shown in Table 1 were used as raw materials, and these were hot-rolled and wound into coils.
After pickling, cold rolling was performed at a rolling reduction of 80% to a sheet thickness of 0.8 mm, and the tensile properties of the steel sheets obtained by performing annealing by an alundum bath treatment for 40 seconds were investigated.
【００２７】[0027]
【表１】 [Table 1]
【００２８】それらの熱間圧延仕上げ温度、巻取り温
度、焼鈍温度及び引張特性の調査結果を表２にまとめて
示す。The results of the examination of the hot rolling finish temperature, winding temperature, annealing temperature and tensile properties are shown in Table 2.
【００２９】[0029]
【表２】 [Table 2]
【００３０】ここに、引張特性はJIS ５号試験片を用い
て行い、平均ｒ値は、15％の引張予ひずみを与えたのち
３点法にて測定し、Ｌ方向（圧延方向）、Ｄ方向（圧延
方向に対し45°方向）及びＣ方向（圧延方向に対し90°
方向) の平均値としてHere, the tensile properties were measured using a JIS No. 5 test piece, and the average r value was measured by a three-point method after a tensile prestrain of 15% was applied. Direction (45 ° to rolling direction) and C direction (90 ° to rolling direction)
Direction)
【数５】平均ｒ値＝（ｒL ＋２ｒD ＋ｒC ) ／４ から求めた。## EQU5 ## The average r value was determined from: (r L + 2r D + r C ) / 4.
【００３１】表２から明らかなように、この発明の適合
例は引張強さが40kgf/mm2 以上で良好な平均ｒ値を示し
ているが、さらに表２の平均ｒ値を（Si（wt％）＋Ｐ
（wt％）／Mn（wt％）のパラメータでまとめると図１の
ようになり、Si、Ｐ及びMnの含有量の関係を、As is apparent from Table 2, the conforming example of the present invention shows a good average r value when the tensile strength is 40 kgf / mm 2 or more. %) + P
(Wt%) / Mn (wt%) are summarized in Fig. 1. The relationship between the contents of Si, P and Mn is
【数６】 0.2 ≦（Si（wt％）＋Ｐ（wt％））／Mn（wt％）≦1.0 とすることにより高い平均ｒ値が得られることがわか
る。It can be seen that a high average r value can be obtained by setting 0.2 ≦ (Si (wt%) + P (wt%)) / Mn (wt%) ≦ 1.0.
【００３２】また、表２から鋼No１及び２について、平
均ｒ値におよぼす巻取り温度の影響をグラフにして示す
と図２のようになり、巻取り温度が高くなり700 ℃にな
るとすでに平均ｒ値は劣化している。FIG. 2 is a graph showing the effect of the winding temperature on the average r value for steel Nos. 1 and 2, as shown in FIG. 2. When the winding temperature is increased to 700 ° C., the average r value is increased. The value has deteriorated.
【００３３】[0033]
【発明の効果】この発明は、極低炭素Ti、Nb、Ｂ複合添
加鋼をベースとして、Si、Mn及びＰの含有量の関係を特
定して含有させることにより、低コストの合金添加で、
しかも通常の連続焼鈍で、耐二次加工脆性に優れる深絞
り加工用高張力冷延鋼板を得るもので、この発明による
鋼板は、経済性にも優れていることから、自動車用、家
電製品用などに用いて有利である。The present invention is based on ultra-low carbon Ti, Nb, and B-added steel, and specifies and contains the relationship between the contents of Si, Mn, and P.
In addition, the steel sheet according to the present invention is used for automobiles and home electric appliances, because it is intended to obtain a high-strength cold-rolled steel sheet for deep drawing with excellent secondary work brittleness resistance by ordinary continuous annealing. It is advantageous to use it for example.
【図１】平均ｒ値を（Si＋Ｐ）／Mnのパラメータでまと
めたグラフである。FIG. 1 is a graph summarizing the average r value with a parameter of (Si + P) / Mn.
【図２】平均ｒ値におよぼす巻取り温度の影響を示すグ
ラフである。FIG. 2 is a graph showing the influence of the winding temperature on the average r value.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 加藤 俊之 千葉県千葉市中央区川崎町１番地 川崎 製鉄株式会社 技術研究本部内 (72)発明者 高崎 順介 千葉県千葉市中央区川崎町１番地 川崎 製鉄株式会社 千葉製鉄所内 (56)参考文献 特開 平３−294463（ＪＰ，Ａ) 特開 平１−205035（ＪＰ，Ａ) 特開 平３−257124（ＪＰ，Ａ) 特開 平１−188630（ＪＰ，Ａ) 特開 平２−163318（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C22C 38/00 - 38/60 C21D 9/46 - 9/48 C21D 8/00 - 8/10 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Toshiyuki Kato 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Engineering Co., Ltd. (56) References JP-A-3-294463 (JP, A) JP-A-1-205035 (JP, A) JP-A-3-257124 (JP, A) JP-A-1-188630 (JP, A) JP-A-2-163318 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) C22C 38/00-38/60 C21D 9/46-9/48 C21D 8 / 00-8/10
Claims (2)
らなることを特徴とする深絞り加工用高張力冷延鋼板。C: 0.001 wt% or more, 0.005 wt% or less, Si: 0.2 wt% or more, 1.0 wt% or less, Mn: 0.5 wt% or more, 2.0 wt% or less, Ti: 0.01 wt% or more, 0.2 wt% %, Nb: 0.001 wt% or more, 0.02 wt% or less, B: 0.0002 wt% or more, 0.005 wt% or less, P: 0.05 wt% or more, 0.15 wt% or less, S: 0.02 wt% or less, sol Al: 0.1 wt% or less and N: 0.005 wt% or less, the content of the Si, Mn and P is as follows: 0.2 ≦ (Si (wt%) + P (wt%)) / Mn (wt%) ≦ 1.0: A high-strength cold-rolled steel sheet for deep drawing, characterized by satisfying the relationship of 1.0 and the balance being composed of iron and unavoidable impurities.
らなる鋼スラブを素材として、Ar3 点（℃）以上、Ar3
点（℃）＋100 ℃以下の圧延仕上げ温度範囲で熱間圧延
を終了し、650 ℃以下の温度で巻取ったのち、冷間圧延
を行い、その後750 ℃以上の温度で連続焼鈍を施すこと
を特徴とする深絞り加工用高張力冷延鋼板の製造方法。2. C: 0.001 wt% or more, 0.005 wt% or less, Si: 0.2 wt% or more, 1.0 wt% or less, Mn: 0.5 wt% or more, 2.0 wt% or less, Ti: 0.01 wt% or more, 0.2 wt% %, Nb: 0.001 wt% or more, 0.02 wt% or less, B: 0.0002 wt% or more, 0.005 wt% or less, P: 0.05 wt% or more, 0.15 wt% or less, S: 0.02 wt% or less, sol Al: 0.1 wt% or less and N: 0.005 wt% or less, the content of the above Si, Mn and P is as follows: 0.2 ≦ (Si (wt%) + P (wt%)) / Mn (wt%) ≦ satisfy the 1.0 relationship, the balance as material a steel slab having a composition of iron and inevitable impurities, Ar 3 point (℃) above, Ar 3
Finish hot rolling at a rolling finish temperature range of point (° C) + 100 ° C or less, wind up at a temperature of 650 ° C or less, perform cold rolling, and then perform continuous annealing at a temperature of 750 ° C or more. Characteristic method for producing high-strength cold-rolled steel sheets for deep drawing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21148392A JP3234642B2 (en) | 1992-08-07 | 1992-08-07 | High tensile cold rolled steel sheet for deep drawing and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21148392A JP3234642B2 (en) | 1992-08-07 | 1992-08-07 | High tensile cold rolled steel sheet for deep drawing and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0657372A JPH0657372A (en) | 1994-03-01 |
| JP3234642B2 true JP3234642B2 (en) | 2001-12-04 |
Family
ID=16606706
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21148392A Expired - Fee Related JP3234642B2 (en) | 1992-08-07 | 1992-08-07 | High tensile cold rolled steel sheet for deep drawing and method for producing the same |
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| Country | Link |
|---|---|
| JP (1) | JP3234642B2 (en) |
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| JP6354299B2 (en) * | 2014-05-01 | 2018-07-11 | 新日鐵住金株式会社 | 440 MPa class high strength alloyed hot dip galvanized steel sheet excellent in secondary work brittleness resistance and method for producing the same |
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1992
- 1992-08-07 JP JP21148392A patent/JP3234642B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0657372A (en) | 1994-03-01 |
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