JPH0673493A - Cold rolled steel sheet excellent in workability, baking hardenability and aging property and its production - Google Patents
Cold rolled steel sheet excellent in workability, baking hardenability and aging property and its productionInfo
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- JPH0673493A JPH0673493A JP22898192A JP22898192A JPH0673493A JP H0673493 A JPH0673493 A JP H0673493A JP 22898192 A JP22898192 A JP 22898192A JP 22898192 A JP22898192 A JP 22898192A JP H0673493 A JPH0673493 A JP H0673493A
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、加工性および焼付硬化
性、時効性に優れた冷延鋼板およびその製造方法に関す
るものである。ここで言う冷延鋼板は、いわゆる冷延鋼
板、および溶融めっき、電気めっきを施した鋼板のこと
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolled steel sheet excellent in workability, bake hardenability and aging property, and a method for producing the same. The cold-rolled steel sheet referred to here is a so-called cold-rolled steel sheet, and a steel sheet that has been subjected to hot dipping and electroplating.
【０００２】[0002]
【従来の技術】冷延鋼板の加工性および焼付硬化性を向
上させる方法としては、例えば特開昭５５−１４１５２
６号公報、特開昭５５−１４１５５５号公報に示される
如く、Ｎｂ添加鋼において、鋼中のＣ、Ｎ、Ａｌ含有量
に応じてＮｂを添加して、ａｔ．％でＮｂ／（固溶Ｃ＋
固溶Ｎ）をある範囲内に制限することにより、鋼板中の
固溶Ｃ、固溶Ｎを調整し、さらに、焼鈍後の冷却速度を
制御する方法が開示されている。2. Description of the Related Art As a method for improving the workability and bake hardenability of a cold rolled steel sheet, for example, JP-A-55-14152.
No. 6, JP-A-55-141555, in Nb-added steel, Nb is added according to the C, N, and Al contents in the steel, and at. % In Nb / (solid solution C +
A method is disclosed in which the solute N) is controlled within a certain range to adjust the solute C and the solute N in the steel sheet and further to control the cooling rate after annealing.
【０００３】また、特公昭６１−４５６８９号公報に
は、ＴｉとＮｂの複合添加によって焼付硬化性に優れた
冷延鋼板とすることが開示され、特公昭５５−２４６２
号公報、特公昭５５−１２１６７号公報には、Ｍｏ、Ｃ
ｒの添加による降伏強度が低く、引張強度が高く、歪時
効処理による回復が著しい低降伏比高張力鋼板およびそ
の製造方法が開示されている。Further, Japanese Patent Publication No. 61-45689 discloses that a cold rolled steel sheet having an excellent bake hardenability is obtained by adding Ti and Nb in combination.
Japanese Patent Publication No. 55-12167, Mo, C
A low-yield-ratio high-strength steel sheet having a low yield strength by addition of r, a high tensile strength, and a remarkable recovery by strain aging treatment, and a method for producing the same are disclosed.
【０００４】さらに、焼付硬化性を有しない超深絞り用
鋼板の製造方法に関するものとしては、Ｔｉキルド鋼板
（特公昭６１−４５６８９号公報）およびＮｂキルド鋼
板（特公昭５４−１２４５号公報）の２つの系列のもの
が開示されている。しかしながら、これらの鋼板は鋼板
中のＣ、Ｎを完全にＴｉあるいはＮｂ等の析出物として
固定しているために、加工性には優れているものの、プ
レス後の塗装焼付時に歪時効現象が起こらず、従って焼
付硬化性を有しないものとなっている。Further, as a method for producing a steel plate for ultra-deep drawing having no bake hardenability, a Ti killed steel plate (Japanese Patent Publication No. 61-45689) and an Nb killed steel plate (Japanese Patent Publication No. 54-1245) are available. Two series are disclosed. However, these steel sheets have excellent workability because C and N in the steel sheet are completely fixed as precipitates such as Ti or Nb, but strain aging phenomenon occurs during coating baking after pressing. Therefore, it has no bake hardenability.
【０００５】このように、冷延鋼板における加工性およ
び焼付硬化性の両方の特性の向上が強く要求されてい
る。As described above, there is a strong demand for improvement in both workability and bake hardenability of cold rolled steel sheets.
【０００６】[0006]
【発明が解決しようとする課題】本発明はこのような要
求を有利に満足する加工性および焼付硬化性、時効性に
優れた冷延鋼板およびその製造方法を提供することを目
的とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a cold rolled steel sheet which is excellent in workability, bake hardenability and aging, and a method for producing the same, which satisfies these requirements.
【０００７】[0007]
【課題を解決するための手段】本発明の要旨とするとこ
ろは下記のとおりである。 （１） 重量％にて、Ｃ：０．００１０％以上０．０１
％以下、Ｓｉ：０．００５％以上０．８％以下、Ｍｎ：
０．０５％以上３％以下、Ｐ：０．００１％以上０．１
５％以下、Ｓ：０．０２０％以下、Ａｌ：０．０１％以
上０．１％以下、Ｎ：０．０１％以下に加えて、Ｍｏ：
０．００１％以上３．０％以下を含み、残部Ｆｅおよび
不可避的不純物からなる加工性および焼付硬化性、時効
性に優れた冷延鋼板。The subject matter of the present invention is as follows. (1) C: 0.0010% or more by weight% 0.01
% Or less, Si: 0.005% or more and 0.8% or less, Mn:
0.05% to 3%, P: 0.001% to 0.1
5% or less, S: 0.020% or less, Al: 0.01% or more and 0.1% or less, N: 0.01% or less, and Mo:
A cold-rolled steel sheet containing 0.001% or more and 3.0% or less and having the balance Fe and unavoidable impurities and being excellent in workability, bake hardenability, and aging.
【０００８】（２） 重量％にて、Ｃ：０．００１０％
以上０．０１％以下、Ｓｉ：０．００５％以上０．８％
以下、Ｍｎ：０．０５％以上３％以下、Ｐ：０．００１
％以上０．１５％以下、Ｓ：０．０２０％以下、Ａｌ：
０．０１％以上０．１％以下、Ｎ：０．０１％以下に加
えて、Ｍｏを０．００１％以上３．０％以下を含み、残
部Ｆｅおよび不可避的不純物からなる鋼を７００℃以上
で熱延した後、５００℃以上の温度で巻取り、しかる後
５０％以上９０％以下の圧下率で冷間圧延後、再結晶温
度以上Ａ3 変態点以下の温度で連続焼鈍を行うことを特
徴とする加工性および焼付硬化性、時効性に優れた冷延
鋼板の製造方法。(2) C: 0.0010% by weight
Or more and 0.01% or less, Si: 0.005% or more and 0.8%
Below, Mn: 0.05% to 3%, P: 0.001
% Or more and 0.15% or less, S: 0.020% or less, Al:
Steel containing 0.01% or more and 0.1% or less, N: 0.01% or less, 0.001% or more and 3.0% or less of Mo, and balance Fe and unavoidable impurities is 700 ° C or more. After hot-rolling at 50 ° C., it is wound at a temperature of 500 ° C. or higher, then cold-rolled at a rolling reduction of 50% to 90%, and then continuously annealed at a temperature of recrystallization temperature or higher and A 3 transformation point or lower. A method for producing a cold rolled steel sheet having excellent workability, bake hardenability and aging characteristics.
【０００９】本発明の対象とする冷延鋼板は、めっき等
を施さない、いわゆる、冷延鋼板、亜鉛等をめっきした
めっき鋼板等で、鋼の溶製方法としては、転炉、電気
炉、平炉等によるいずれの方法でもよく、鋳型による鋼
塊鋳造後分塊圧延したスラブ、連続鋳造によるスラブ等
を出発材として用い得るが、その製造方法は問わない。
本発明者らは、冷延鋼板の加工性および焼付硬化性、時
効性を向上させるために、種々の研究を重ねた結果、重
量％にて、Ｃ：０．００１０％以上０．０１％以下、Ｓ
ｉ：０．００５％以上０．８％以下、Ｍｎ：０．０５％
以上３％以下、Ｐ：０．００１％以上０．１５％以下、
Ｓ：０．０２０％以下、Ａｌ：０．０１％以上０．１％
以下、Ｎ：０．０１％以下に加えて、さらに、Ｍｏを
０．００１％以上３．０％以下を含み、残部Ｆｅおよび
不可避的不純物からなる鋼を７００℃以上で熱延した
後、５００℃以上の温度で巻取り、しかる後５０％以上
９０％以下の圧下率で冷間圧延後、再結晶温度以上Ａ3
変態点以下の温度で連続焼鈍を行うことによって、加工
性、時効性に優れており、しかも焼付硬化性が大幅に改
善された冷延鋼板が得られることを見出した。The cold-rolled steel sheet to which the present invention is applied is a so-called cold-rolled steel sheet which is not plated or the like, a plated steel sheet which is plated with zinc or the like. Any method using a flat furnace or the like may be used, and a slab obtained by slab rolling after casting a steel ingot by a mold, a slab obtained by continuous casting, or the like can be used as a starting material, but the manufacturing method is not limited.
The present inventors have conducted various studies in order to improve workability, bake hardenability, and aging of cold rolled steel sheets, and as a result, in% by weight, C: 0.0010% or more and 0.01% or less. , S
i: 0.005% or more and 0.8% or less, Mn: 0.05%
Or more and 3% or less, P: 0.001% or more and 0.15% or less,
S: 0.020% or less, Al: 0.01% or more and 0.1%
Hereinafter, in addition to N: 0.01% or less, a steel containing 0.001% or more and 3.0% or less of Mo and the balance Fe and unavoidable impurities is hot-rolled at 700 ° C. or more, and then 500 Winding at a temperature of ℃ or more, then cold rolling at a reduction rate of 50% or more and 90% or less, then recrystallization temperature or more A 3
It has been found that by performing continuous annealing at a temperature below the transformation point, a cold-rolled steel sheet having excellent workability and aging property and having significantly improved bake hardenability can be obtained.
【００１０】従来の上記冷延鋼板においては、加工性は
優れていても焼付硬化性を有しないものとなったり、焼
付硬化性を有してもその量が少なく、しかも時効性を損
なうもので両立せず、不安定であり、加工性が劣るもの
であった。本発明の鋼の成分を限定した理由は以下のと
おりである。まず、Ｃ：Ｃは０．００１０％以上０．０
１％以下とする。下限を０．００１０％としたのは、Ｃ
量が低いほど加工性は良いが、これ未満であると固溶Ｃ
の量が十分でなく、焼付硬化性を高めるのに必要な量で
ないためである。また、上限を０．０１％としたのは、
これを超えるとＣは鋼の強化元素であるから、強度が高
くなりすぎ、加工性を損なうためである。In the above-mentioned conventional cold-rolled steel sheet, it has a good workability but does not have bake hardenability, or has a bake hardenability, but its amount is small and the aging property is impaired. They were incompatible, unstable, and poor in workability. The reasons for limiting the components of the steel of the present invention are as follows. First, C: C is 0.0010% or more and 0.0
1% or less. The lower limit of 0.0010% is C
The lower the amount, the better the workability, but if it is less than this, solid solution C
This is because the amount is not sufficient and it is not an amount necessary to enhance the bake hardenability. The upper limit of 0.01% is
This is because if it exceeds this, C is a strengthening element of steel, so that the strength becomes too high and the workability is impaired.
【００１１】Ｓｉ：Ｓｉは０．００５％以上０．８％以
下とする。Ｓｉは鋼の強化元素であり、必要とする強度
に応じて添加し、その下限を０．００５％とする。上限
を０．８％としたのは、それを超えると強度が高くなり
すぎ、加工性を損なうためであり、また亜鉛めっき等を
行うときには亜鉛が付着しにくく、密着性を損なうため
である。Si: Si is set to 0.005% or more and 0.8% or less. Si is a strengthening element of steel, and is added according to the required strength, and the lower limit is made 0.005%. The upper limit is set to 0.8% because if it exceeds the upper limit, the strength becomes too high and the workability is impaired, and when galvanizing or the like, zinc is hard to adhere and the adhesion is impaired.
【００１２】Ｍｎ：Ｍｎは０．０５％以上３％以下とす
る。Ｍｎは鋼の強化元素であり、必要とする強度に応じ
て添加し、その下限を０．０５％とする。上限を３％と
したのは、３％を超えると強度が高くなりすぎて加工性
を損なうためである。 Ｐ：Ｐは０．００１％以上０．１５％以下とする。Ｐは
少量でも鋼の強化元素であり、必要とする強度に応じて
添加し、その下限を０．００１％とする。上限を０．１
５％としたのは、それを超えると強度が高くなりすぎて
加工性を損なうためであり、しかもＰは結晶粒界に濃化
して、粒界脆化を起こしやすい元素であり、０．１５％
を超えて添加すると加工性を損なうためである。Mn: Mn is set to 0.05% or more and 3% or less. Mn is a strengthening element for steel, and is added according to the required strength, and the lower limit is 0.05%. The upper limit is set to 3% because if it exceeds 3%, the strength becomes too high and the workability is impaired. P: P is 0.001% or more and 0.15% or less. P is a strengthening element of steel even in a small amount, and is added according to the required strength, and the lower limit is made 0.001%. The upper limit is 0.1
The reason why 5% is set is that if it exceeds 5%, the strength becomes too high and the workability is impaired, and moreover, P is an element which tends to concentrate in the crystal grain boundaries and cause grain boundary embrittlement. %
This is because if it is added over the range, the workability is impaired.
【００１３】Ｓ：Ｓを０．０２０％以下としたのは、本
来鋼中に存在することが無意味な元素であり、０．０２
０％を超えて添加すると、Ｍｎ等の硫化物生成元素が少
ないと熱間圧延時に赤熱脆性を起こし、表面が割れる、
いわゆる熱間脆性を起こすことがあるためである。 Ａｌ：Ａｌは０．０１以上０．１％以下とする。下限を
０．０１％としたのは、これ未満ではＮをＡｌＮとして
析出させ、Ｎによる時効性を改善することが困難になる
ためである。また、その上限を０．１％としたのは、こ
れを超えて添加しても、時効性の向上は飽和し、しかも
強度が高くなりすぎて加工性を損なうためである。S: S is set to 0.020% or less because it is a meaningless element originally present in steel.
If added in excess of 0%, if the amount of sulfide-forming elements such as Mn is small, red hot embrittlement will occur during hot rolling, and the surface will crack.
This is because so-called hot brittleness may occur. Al: Al is 0.01% or more and 0.1% or less. The lower limit is set to 0.01% because if it is less than this, it becomes difficult to precipitate N as AlN and improve the aging property by N. Further, the upper limit is set to 0.1% because if it is added over this amount, the improvement in aging is saturated and the strength becomes too high and the workability is impaired.
【００１４】Ｎ：Ｎを０．０１％以下としたのは、これ
を超えて添加する場合は、Ａｌの添加量を多くしないと
時効性を確保できず、しかも強度が高くなりすぎて加工
性を損なうためである。 Ｍｏ：Ｍｏは０．００１％以上３．０％以下とする。下
限を０．００１％としたのは、これ未満では焼付硬化性
を高くする効果がないためである。また、上限を３．０
％としたのは、これを超えるとＭｏが鋼の強化元素であ
り、強度が高くなりすぎて加工性を損なうためであり、
焼付硬化性も飽和してしまうために、高価で経済的にな
りたたなくなるためである。ＭｏはＦｅ3 Ｃの核生成を
抑制し、パーライト変態を抑制する元素であることが知
られているが、焼付硬化性を高くする理由は明らかでは
ないが、低炭素鋼のために、添加したＭｏが固溶して多
くの歪場を作るために、加工歪の少ない部位での塗装焼
付時の１７０℃程度の低温でも、容易に残存している固
溶炭素、固溶窒素との析出物を生成するか、クラスター
状となり、可動転位を固着して硬化すると考えられる。
反対に、ＭｏとＣの析出物やクラスターを生成するので
はなく、Ｍｏの周囲にＣが集まったコンプレッションを
作り、常温ではＣの移動を抑制して、塗料の焼付温度の
１７０〜２００℃でＭｏ−Ｃが離れて、Ｃは転位を固着
して硬化するとも考えられる。いずれにしても、Ｍｏを
添加した効果が焼付硬化性の向上として表れると考えら
れる。N: N is set to 0.01% or less because if it is added in excess of this, the aging cannot be secured unless the amount of Al added is increased, and the strength becomes too high and the workability is increased. This is because it impairs Mo: Mo is 0.001% or more and 3.0% or less. The lower limit is set to 0.001% because if it is less than this, there is no effect of increasing the bake hardenability. Also, the upper limit is 3.0
%, Since Mo is a strengthening element of steel and the strength becomes too high and the workability is impaired if it exceeds this range.
This is because the bake hardenability is saturated and it becomes expensive and economical. Mo is known to be an element that suppresses the nucleation of Fe 3 C and suppresses the pearlite transformation, but the reason for increasing the bake hardenability is not clear, but it was added because of the low carbon steel. Precipitates with solute carbon and solute nitrogen that easily remain even at a low temperature of about 170 ° C. during baking of a coating in a region where processing strain is small, since Mo forms a large amount of strain field as a solid solution. It is considered that the solid dislocations are formed or clustered and mobile dislocations are fixed and hardened.
On the other hand, rather than forming precipitates and clusters of Mo and C, it creates a compression of C around Mo and suppresses the migration of C at room temperature, so that at a baking temperature of 170 to 200 ° C. of the paint. It is also considered that Mo-C separates and C fixes dislocations and hardens. In any case, it is considered that the effect of adding Mo appears as an improvement in bake hardenability.
【００１５】その他、含有する元素として、Ｂについて
は添加することを限定するものではないが、焼入性を向
上させ、強度を高めるためと二次加工性を向上させるた
めに０．００１０％程度添加してもよい。次に、熱延条
件として仕上圧延終了温度を７００℃以上としたのは、
それ未満では圧延組織が残存し、冷延圧下時その圧下量
が大きくなり、不利となるためである。また、加工性を
向上させるには、熱延終了時の結晶粒はランダムなほど
よいとされており、圧延組織が残存することは結晶の集
合組織の面からも加工性に悪影響を及ぼすからである。
また、上限については、限定するものではないが９６０
℃未満が適当である。In addition, although addition of B as an element to be contained is not limited, about 0.0010% is added to improve hardenability, strength and secondary workability. You may add. Next, as the hot rolling condition, the finish rolling end temperature is set to 700 ° C. or higher,
This is because if it is less than that, the rolling structure remains and the amount of reduction becomes large during cold rolling reduction, which is disadvantageous. Further, in order to improve the workability, it is said that it is better that the crystal grains at the end of hot rolling are random, and that the remaining rolling structure adversely affects the workability in terms of the texture of the crystal. is there.
The upper limit is not limited to 960.
A temperature of less than 0 ° C is suitable.
【００１６】巻取温度を５００℃以上としたのは、鋼板
の加工性を向上させるために結晶粒を大きくすることが
必要であり、高温からの冷却過程での結晶粒の成長が見
込まれるためである。また、冷間圧延の圧下率は５０％
以上９０％以下として、下限を５０％としたのは再結晶
温度以上Ａ3 変態点以下の温度で連続焼鈍を行うことを
条件として、冷間圧延率は加工性を良くする最適点があ
り、冷間圧延前に歪が蓄えられていたとしても、５０％
未満では冷延集合組織を調整し、焼鈍集合組織を最適に
して絞り加工性を向上させることができないためであ
る。冷延圧下率の上限を９０％としたのはそれを超えて
歪を加えると冷延集合組織の（１００）面が多くなり、
焼鈍後の集合組織にも絞り加工性に悪い（１００）面が
残り、絞り加工性を損なうためであり、冷間圧延前の歪
と合わせると冷間圧延での歪は少なくてよいためであ
る。つまり、冷延圧下率は冷延鋼板の最終板厚に合わせ
ることだけでなく、集合組織をよくするために最適点が
あり、工業的にもその意義は大きい。The reason why the coiling temperature is set to 500 ° C. or higher is that it is necessary to make the crystal grains large in order to improve the workability of the steel sheet, and the crystal grains are expected to grow in the cooling process from a high temperature. Is. The cold rolling reduction rate is 50%.
The lower limit is set to 90% or less, and the lower limit is set to 50% on condition that continuous annealing is performed at a temperature not lower than the recrystallization temperature and not higher than the A 3 transformation point, and the cold rolling ratio has an optimum point for improving workability. 50% even if strain is accumulated before cold rolling
If it is less than the above range, the cold rolling texture cannot be adjusted and the annealing texture cannot be optimized to improve the drawability. The upper limit of the cold rolling reduction ratio is 90%. When strain is applied beyond that, the (100) plane of the cold rolling texture increases,
This is because the (100) plane having poor drawability remains in the texture after annealing and impairs drawability, and when combined with the strain before cold rolling, the strain in cold rolling may be small. . That is, the cold rolling reduction has an optimum point not only for adjusting to the final thickness of the cold rolled steel sheet but also for improving the texture, which is industrially significant.
【００１７】さらに、連続焼鈍の温度条件を再結晶温度
以上Ａ3 変態点以下として、その下限を再結晶温度とし
たのは、それ未満では冷間圧延によって生成した歪が除
去されず、しかも再結晶しないために加工性の優れた結
晶とならず、加工性が劣るためである。また、その上限
をＡ3 変態点としたのは、それを超えて焼鈍すると再結
晶粒が粗大化して加工後の鋼板表面が肌荒れを呈し、外
観上の問題を生じるためである。なお、焼鈍時の加熱速
度は高速なほど加工生を良くする（１１１）面の発達が
促進されるといわれているが、特に規定するものではな
い。Further, the temperature condition of the continuous annealing is set to the recrystallization temperature or more and the A 3 transformation point or less and the lower limit is set to the recrystallization temperature. Below that, the strain generated by cold rolling is not removed, This is because, since it does not crystallize, it does not become a crystal with excellent workability and the workability is poor. The upper limit is set to the A 3 transformation point because if it is annealed beyond that, the recrystallized grains become coarse, and the surface of the steel sheet after processing becomes rough, causing a problem in appearance. It is said that the higher the heating rate during annealing, the faster the development of the (111) plane that improves the workability, but this is not particularly specified.
【００１８】焼鈍時間は、特に規定するものではない
が、温度との関係で温度が高いと時間が短く、低いと長
くなる再結晶完了時間以上とすればよい。焼鈍後の冷却
速度は規定するものではないが、焼付硬化性を高くする
点から急速冷却することが望ましい。その後の、調質圧
延は形状調整のために実施してもよいが、そのまま調質
圧延をしないで製品としてもよい。調質圧延をしなくて
も降伏点伸びがなく、加工性がよいのは前述のとおり可
動転位を多く残存させて製造できる方法であるからであ
り、調質圧延を行わないことにより、降伏点が低く加工
が容易になる点でも有利である。Although the annealing time is not particularly specified, it may be set to a recrystallization completion time longer than the recrystallization completion time when the temperature is high or long when the temperature is low. The cooling rate after annealing is not specified, but rapid cooling is desirable from the viewpoint of enhancing the bake hardenability. Subsequent temper rolling may be carried out to adjust the shape, but it may be a product without temper rolling as it is. The yield point does not extend even without temper rolling, and the workability is good because it is a method that can be produced by leaving a large number of mobile dislocations as described above. It is also advantageous in that the workability is low and processing is easy.
【００１９】このようにして成分を調整し、製造した冷
延鋼板は図１に示すとおり、熱延仕上温度が７００℃以
上、Ａ3 変態点未満でｒ値が高く、加工性の良い冷延鋼
板となっている。また、図２に示すとおり、Ｍｏの添加
によって焼付硬化性に優れた鋼板とすることができる。
Ｍｏの添加量が０．００１％以上３．０％以下の領域で
焼付硬化量は高くなり、しかも、降伏点伸びのない、加
工性の良い焼付硬化性に優れた冷延鋼板とすることがで
きる。As shown in FIG. 1, the cold-rolled steel sheet produced by adjusting the components in this way has a hot rolling finish temperature of 700 ° C. or higher and a low r value at a temperature lower than the A 3 transformation point, and has good workability. It is a steel plate. Further, as shown in FIG. 2, by adding Mo, it is possible to obtain a steel sheet having excellent bake hardenability.
It is possible to obtain a cold-rolled steel sheet which has a high bake hardening amount in the region where the amount of addition of Mo is 0.001% or more and 3.0% or less, and has no yield point elongation and is excellent in workability and excellent in bake hardenability. it can.
【００２０】かくして、鋼の成分を調整し、熱延条件、
冷延条件、焼鈍条件を調整することで、加工性および焼
付硬化性、時効性に優れた冷延鋼板とすることができ
る。しかして、前記の如き加工性および焼付硬化性、時
効性に優れた冷延鋼板とする成分、および製造する方法
としては、鋳型による鋳造または連続鋳造等で、重量％
にて、Ｃ：０．００１０％以上０．０１％以下、Ｓｉ：
０．００５％以上０．８％以下、Ｍｎ：０．０５％以上
３％以下、Ｐ：０．００１％以上０．１５％以下、Ｓ：
０．０２０％以下、Ａｌ：０．０１％以上０．１％以
下、Ｎ：０．０１％以下に加えて、さらに、Ｍｏ：０．
００１％以上３．０％以下を含み、残部Ｆｅおよび不可
避的不純物からなる鋼とすること、およびこのような化
学成分組成とした鋼を７００℃以上で熱延した後、５０
０℃以上の温度で巻取り、しかる後５０％以上９０％以
下の圧下率で冷間圧延後、再結晶温度以上Ａ3 変態点以
下の温度で連続焼鈍を行うことによって、加工性に優
れ、ストレッチャーストレインの生成しない、時効性に
優れ、しかも焼付硬化性を大幅に改善した冷延鋼板を製
造することができる。Thus, the composition of the steel is adjusted, the hot rolling conditions,
By adjusting the cold rolling conditions and the annealing conditions, a cold rolled steel sheet having excellent workability, bake hardenability, and aging can be obtained. Thus, the workability and bake hardenability as described above, the components to be a cold-rolled steel sheet excellent in aging property, and the manufacturing method include casting by a mold or continuous casting, and the weight%
At C: 0.0010% or more and 0.01% or less, Si:
0.005% to 0.8%, Mn: 0.05% to 3%, P: 0.001% to 0.15%, S:
In addition to 0.020% or less, Al: 0.01% or more and 0.1% or less, N: 0.01% or less, Mo: 0.
A steel containing 001% or more and 3.0% or less and the balance Fe and unavoidable impurities is used, and steel having such a chemical composition is hot-rolled at 700 ° C. or more and then 50
By winding at a temperature of 0 ° C. or higher, then cold rolling at a reduction ratio of 50% to 90%, and then performing continuous annealing at a temperature of recrystallization temperature or higher and A 3 transformation point or lower, excellent workability is achieved. It is possible to produce a cold-rolled steel sheet that does not generate stretcher strain, has excellent aging properties, and has greatly improved bake hardenability.
【００２１】なお、かくして製造した鋼板に例えばＺｎ
を電気めっきして、防錆鋼板とすることができ、焼付硬
化性に優れた防錆鋼板とすることができ、またかかる成
分の鋼を熱延、冷間圧延後、再結晶温度以上Ａ3 変態点
以下の温度で連続焼鈍を行った後、直ちに溶融亜鉛めっ
きを施し、加えて合金化処理を行うことによって、高強
度化、高防錆化にも寄与できる合金化溶融亜鉛めっき鋼
板とすることが可能である。In addition, the steel sheet thus manufactured may be made of, for example, Zn.
Can be electroplated to form a rust-preventing steel plate, which can be a rust-preventing steel plate excellent in bake hardenability. Further, steel of such a component is hot-rolled, cold-rolled, and then recrystallized at a temperature of A 3 or more. After continuous annealing at a temperature below the transformation point, hot dip galvanizing is performed immediately, and alloying treatment is performed in addition to the alloyed hot dip galvanized steel sheet that can contribute to high strength and high rust prevention. It is possible.
【００２２】[0022]
【実施例】次に本発明の実施例を比較例とともに表１〜
３に挙げる。表１に鋼の成分、表２および表３（表２の
つづき）に鋼の製造条件と特性値を示す。EXAMPLES Next, examples of the present invention along with comparative examples are shown in Tables 1 to 1.
Listed in 3. Table 1 shows the components of the steel, and Tables 2 and 3 (continued from Table 2) show the steel production conditions and characteristic values.
【００２３】[0023]
【表１】 [Table 1]
【００２４】[0024]
【表２】 [Table 2]
【００２５】[0025]
【表３】 [Table 3]
【００２６】[0026]
【発明の効果】本発明によれば、加工性および焼付硬化
性、時効性に優れた冷延鋼板、例えば自動車用の外板に
使用され得る、耐デント性に優れ、加工時に軟質で、使
用時に硬質になる特性を具備する冷延鋼板を提供するこ
とができる。INDUSTRIAL APPLICABILITY According to the present invention, cold-rolled steel sheets having excellent workability, bake hardenability, and aging, which can be used as outer panels for automobiles, have excellent dent resistance, are soft during processing, and can be used. It is possible to provide a cold-rolled steel sheet having the property of becoming hard at times.
【図１】冷延鋼板の熱延仕上温度とｒ値の関係を示す図
である。 （図１の冷延鋼板の組成、製造条件） Ｃ：０．００３０％ Ｓｉ：０．０１３％ Ｍｎ：０．１４０％ Ｐ：０．０１０％ Ｓ：０．００４％ Ａｌ：０．０４０％ Ｎ：０．００２５％ Ｍｏ、Ｗ、Ｃｒの合計量：０．１３％ 熱延仕上温度：６５０〜９３０℃ 熱延巻取温度：６００℃ 冷間圧延率：８０％ 冷延最終板厚：０．８ｍｍ 焼鈍温度：８００℃×４０ｓｅｃ 冷却速度：１００℃／ｓｅｃ 調質圧延率：０．８％FIG. 1 is a diagram showing a relationship between a hot rolling finish temperature of a cold rolled steel sheet and an r value. (Composition and manufacturing conditions of the cold-rolled steel sheet of FIG. 1) C: 0.0030% Si: 0.013% Mn: 0.140% P: 0.010% S: 0.004% Al: 0.040% N : 0.0025% Total amount of Mo, W, Cr: 0.13% Hot rolling finishing temperature: 650 to 930 ° C Hot rolling coiling temperature: 600 ° C Cold rolling rate: 80% Cold rolling final sheet thickness: 0. 8 mm Annealing temperature: 800 ° C. × 40 sec Cooling rate: 100 ° C./sec Temper rolling ratio: 0.8%
【図２】冷延鋼板のＭｏの添加量と焼付硬化性の関係を
示す図である。 （図２の冷延鋼板の組成、製造条件） Ｃ：０．００３０％ Ｓｉ：０．０１３％ Ｍｎ：０．１４０％ Ｐ：０．０１０％ Ｓ：０．００４％ Ａｌ：０．０４０％ Ｎ：０．００２５％ Ｍｏ：０．１３％ 熱延仕上温度：６５０〜９３０℃ 熱延巻取温度：６００℃ 冷間圧延率：８０％ 冷延最終板厚：０．８ｍｍ 焼鈍温度：８００℃×４０ｓｅｃ 冷却速度：１００℃／ｓｅｃ 調質圧延率：０．８％FIG. 2 is a diagram showing the relationship between the amount of Mo added to a cold rolled steel sheet and bake hardenability. (Composition and manufacturing conditions of the cold-rolled steel sheet in FIG. 2) C: 0.0030% Si: 0.013% Mn: 0.140% P: 0.010% S: 0.004% Al: 0.040% N : 0.0025% Mo: 0.13% Hot rolling finishing temperature: 650 to 930 ° C Hot rolling coiling temperature: 600 ° C Cold rolling ratio: 80% Cold rolling final sheet thickness: 0.8mm Annealing temperature: 800 ° C 40 sec Cooling rate: 100 ° C./sec Temper rolling ratio: 0.8%
Claims (2)
０．０１％以下、Ｓｉ：０．００５％以上０．８％以
下、Ｍｎ：０．０５％以上３％以下、Ｐ：０．００１％
以上０．１５％以下、Ｓ：０．０２０％以下、Ａｌ：
０．０１％以上０．１％以下、Ｎ：０．０１％以下に加
えて、Ｍｏ：０．００１％以上３．０％以下を含み、残
部Ｆｅおよび不可避的不純物からなる加工性および焼付
硬化性、時効性に優れた冷延鋼板。1. In% by weight, C: 0.0010% or more and 0.01% or less, Si: 0.005% or more and 0.8% or less, Mn: 0.05% or more and 3% or less, P: 0. .001%
0.15% or less, S: 0.020% or less, Al:
In addition to 0.01% or more and 0.1% or less, N: 0.01% or less, Mo: 0.001% or more and 3.0% or less, and the balance Fe and unavoidable impurities for workability and bake hardening. Cold rolled steel sheet with excellent heat resistance and aging properties.
０．０１％以下、Ｓｉ：０．００５％以上０．８％以
下、Ｍｎ：０．０５％以上３％以下、Ｐ：０．００１％
以上０．１５％以下、Ｓ：０．０２０％以下、Ａｌ：
０．０１％以上０．１％以下、Ｎ：０．０１％以下に加
えて、Ｍｏを０．００１％以上３．０％以下を含み、残
部Ｆｅおよび不可避的不純物からなる鋼を７００℃以上
で熱延した後、５００℃以上の温度で巻取り、しかる後
５０％以上９０％以下の圧下率で冷間圧延後、再結晶温
度以上Ａ3 変態点以下の温度で連続焼鈍を行うことを特
徴とする加工性および焼付硬化性、時効性に優れた冷延
鋼板の製造方法。2. In% by weight, C: 0.0010% or more and 0.01% or less, Si: 0.005% or more and 0.8% or less, Mn: 0.05% or more and 3% or less, P: 0. .001%
0.15% or less, S: 0.020% or less, Al:
Steel containing 0.01% or more and 0.1% or less, N: 0.01% or less, 0.001% or more and 3.0% or less of Mo, and balance Fe and unavoidable impurities is 700 ° C or more. After hot-rolling at 50 ° C., it is wound at a temperature of 500 ° C. or higher, then cold-rolled at a rolling reduction of 50% to 90%, and then continuously annealed at a temperature of recrystallization temperature or higher and A 3 transformation point or lower. A method for producing a cold rolled steel sheet having excellent workability, bake hardenability and aging characteristics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22898192A JP2631437B2 (en) | 1992-08-27 | 1992-08-27 | Cold rolled steel sheet excellent in workability, bake hardenability and aging, and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22898192A JP2631437B2 (en) | 1992-08-27 | 1992-08-27 | Cold rolled steel sheet excellent in workability, bake hardenability and aging, and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0673493A true JPH0673493A (en) | 1994-03-15 |
| JP2631437B2 JP2631437B2 (en) | 1997-07-16 |
Family
ID=16884902
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22898192A Expired - Lifetime JP2631437B2 (en) | 1992-08-27 | 1992-08-27 | Cold rolled steel sheet excellent in workability, bake hardenability and aging, and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2631437B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020046708A (en) * | 2000-12-15 | 2002-06-21 | 이구택 | method of manufacturing cold rolled steel sheets with excellent anti-aging properties for automotive structural parts |
| JP2013164115A (en) * | 2012-02-10 | 2013-08-22 | Tokkyokiki Corp | Damping device of vibration isolation mount |
-
1992
- 1992-08-27 JP JP22898192A patent/JP2631437B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020046708A (en) * | 2000-12-15 | 2002-06-21 | 이구택 | method of manufacturing cold rolled steel sheets with excellent anti-aging properties for automotive structural parts |
| JP2013164115A (en) * | 2012-02-10 | 2013-08-22 | Tokkyokiki Corp | Damping device of vibration isolation mount |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2631437B2 (en) | 1997-07-16 |
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