JPH02141534A - Production of cold rolled steel sheet having delayed aging property - Google Patents
Production of cold rolled steel sheet having delayed aging propertyInfo
- Publication number
- JPH02141534A JPH02141534A JP29236188A JP29236188A JPH02141534A JP H02141534 A JPH02141534 A JP H02141534A JP 29236188 A JP29236188 A JP 29236188A JP 29236188 A JP29236188 A JP 29236188A JP H02141534 A JPH02141534 A JP H02141534A
- Authority
- JP
- Japan
- Prior art keywords
- steel sheet
- temperature
- seconds
- rolled
- steel
- 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
- 239000010960 cold rolled steel Substances 0.000 title claims abstract description 22
- 238000004519 manufacturing process Methods 0.000 title claims description 16
- 230000003679 aging effect Effects 0.000 title abstract description 5
- 230000003111 delayed effect Effects 0.000 title abstract 3
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 44
- 238000000137 annealing Methods 0.000 claims abstract description 44
- 239000010959 steel Substances 0.000 claims abstract description 44
- 238000000034 method Methods 0.000 claims abstract description 35
- 238000001816 cooling Methods 0.000 claims abstract description 31
- 238000005096 rolling process Methods 0.000 claims abstract description 30
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 19
- 238000005098 hot rolling Methods 0.000 claims abstract description 12
- 238000001953 recrystallisation Methods 0.000 claims abstract description 12
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 11
- 230000009466 transformation Effects 0.000 claims abstract description 9
- 239000012535 impurity Substances 0.000 claims abstract description 7
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 6
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 4
- 238000010438 heat treatment Methods 0.000 claims description 25
- 238000005097 cold rolling Methods 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 230000032683 aging Effects 0.000 abstract description 31
- 229910000655 Killed steel Inorganic materials 0.000 abstract description 8
- RQMIWLMVTCKXAQ-UHFFFAOYSA-N [AlH3].[C] Chemical compound [AlH3].[C] RQMIWLMVTCKXAQ-UHFFFAOYSA-N 0.000 abstract 1
- 238000002425 crystallisation Methods 0.000 abstract 1
- 230000008025 crystallization Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 27
- 239000006104 solid solution Substances 0.000 description 15
- 238000002474 experimental method Methods 0.000 description 11
- 238000001556 precipitation Methods 0.000 description 11
- 238000002791 soaking Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 7
- 238000005554 pickling Methods 0.000 description 7
- 239000007787 solid Substances 0.000 description 7
- 239000002244 precipitate Substances 0.000 description 6
- 238000004804 winding Methods 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 239000013078 crystal Substances 0.000 description 5
- 230000035882 stress Effects 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 229910052698 phosphorus Inorganic materials 0.000 description 4
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 3
- 238000005238 degreasing Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000007779 soft material Substances 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000001376 precipitating effect Effects 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 229910052720 vanadium 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、低炭素／Ｖキルド銅を素材とし、短時間過時
効処理を伴う連続焼鈍法で時効劣化の小さい冷延鋼板を
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 is a method for producing cold-rolled steel sheets with low aging deterioration using low carbon/V-killed copper as a material and using a continuous annealing method with short-time overaging treatment. It is related to.
〈従来の技術〉
従来、冷延鋼板の製造における焼鈍工程は、箱焼鈍法に
よって行われていた。この箱焼鈍法は、冷延綱帯をコイ
ル状態のまま、数日間かけて再結晶焼鈍を行い、焼鈍過
程において材質を劣化させる鋼中の固溶Ｃ，Ｎを析出さ
せ、材質を軟質化させる方法であるが、昇温・冷却に数
日乃至数週間かかるばかりでなく、コイル内・外径の温
度が不均一であり、コイル内の材質がかなり不均一であ
った。<Prior Art> Conventionally, the annealing process in the production of cold-rolled steel sheets has been performed by a box annealing method. In this box annealing method, the cold-rolled steel strip is recrystallized in a coiled state for several days, and solid solution C and N in the steel, which deteriorate the material, are precipitated during the annealing process, softening the material. However, not only did it take several days to several weeks to raise and cool the temperature, but the temperature inside and outside the coil was uneven, and the material inside the coil was quite uneven.
近年、この箱焼鈍法に対してラインスピードが１００〜
４００ｍｐｍで通板され、ｌコイルを焼鈍するに要する
時間が数分〜数十分間で完了する連続焼鈍法が広く適用
されてきており、連続焼鈍法は箱焼鈍法にとってかわり
つつある。In recent years, line speeds have increased from 100 to 100 for this box annealing method.
The continuous annealing method, in which the sheet is threaded at 400 mpm and the time required to annealing one coil is completed in several minutes to several tens of minutes, has been widely applied, and the continuous annealing method is replacing the box annealing method.
しかし、連続焼鈍法は加熱・冷却速度が速く鋼中の固溶
Ｃ，Ｈの析出が起こりにくく、そのため焼鈍後、数日以
上経過すると時効劣化が起こり鋼板の降伏点が上昇する
とともに降伏伸びが発生しやすくなり材質が硬質化する
他、加工した際にストレッチャー・ストレインといった
表面欠陥が発生してしまう等の問題があった。However, the continuous annealing method has a fast heating and cooling rate, making it difficult for solid solution C and H to precipitate in the steel. Therefore, after several days have passed after annealing, aging deterioration occurs, the yield point of the steel sheet increases, and the yield elongation decreases. In addition to making the material harder and more likely to occur, there were other problems such as surface defects such as stretcher strain occurring during processing.
この連続焼鈍法のかかえる問題を解決するために、次の
ような方法がとられている。In order to solve the problems of this continuous annealing method, the following methods have been adopted.
しかしながら、これら（１）〜（３）の方法も完全では
ない。たとえば、（１）のように熱延巻取温度を高温と
した場合、コイル内・外径方向１幅方向に冷却むらを生
じて同一コイル内での材質の均一性が悪くなる他、酸化
膜が厚くなり、酸洗工程での脱スケールが悪くなって完
全に脱スケールを行うためには酸洗ラインのラインスピ
ードを低下させなければならなくなり、生産性を著しく
損なってしまう。また酸洗液の取替頻度が多くなりコス
トアップを招（等の問題があった。However, these methods (1) to (3) are also not perfect. For example, if the hot rolling winding temperature is set to a high temperature as in (1), uneven cooling will occur in one width direction in the inner and outer diameter direction of the coil, resulting in poor material uniformity within the same coil, as well as an oxide film. becomes thicker, descaling in the pickling process becomes worse, and in order to completely descale, it is necessary to reduce the line speed of the pickling line, which significantly impairs productivity. In addition, the pickling solution had to be replaced more frequently, leading to increased costs.
（２）の手段のように焼鈍中に急冷・過時効処理を行っ
て固溶Ｃ量の低減を行うには、前述のようにラインスピ
ードが１００〜４００ｍｐｍで通板されている鋼板に３
分間以上の過時効処理を行うとなると、必然的に長大な
過時効帯を有する連続焼鈍設備が必要となり、設備的な
限界及び制限が生じてくる。In order to reduce the amount of solid solute C by performing rapid cooling and overaging treatment during annealing as in the method (2), it is necessary to
If over-aging treatment is to be carried out for more than 1 minute, continuous annealing equipment having a long over-aging zone is inevitably required, resulting in equipment limitations and restrictions.
しかし短時間の過時効処理では遅時効性の冷延鋼板とす
るに十分な鋼中の固溶Ｃ量まで低減することは不可能で
あり、軟質材を得ることは困難であった。However, by short-time overaging treatment, it is impossible to reduce the amount of solid solute C in the steel to a level sufficient to produce a slow-aging cold-rolled steel sheet, and it has been difficult to obtain a soft material.
（１） 熱延後の巻取を６５０℃以」二の高温巻取と
し、熱延鋼帯の時点で、Ｆｅ５Ｃ＋ ＡＺＮ等の析出物
を析出させておいて軟質材を得る手段。(1) A method of obtaining a soft material by performing high-temperature winding at 650° C. or higher after hot rolling, and precipitating precipitates such as Fe5C+AZN at the time of hot-rolled steel strip.
（２）連続焼鈍中の加熱・均熱後の冷却過程で急冷・過
時効処理を施し、鋼中のカーバイトを析出させる手段。(2) A means of precipitating carbide in the steel by performing rapid cooling and overaging treatment in the cooling process after heating and soaking during continuous annealing.
すなわち、加熱・均熱後に５０〜１００℃／秒の冷却速
度で急速冷却し、結晶粒内の固溶Ｃの過飽和度を高めて
、３００〜５００℃の温度域に３分間以上の保持を行い
、固溶Ｃの析出サイトである結晶粒内のカーバイト及び
結晶粒界に固溶Ｃを拡散させ、Ｐｅ３Ｃの析出を促進さ
せて軟質材を得る手段。That is, after heating and soaking, it is rapidly cooled at a cooling rate of 50 to 100 °C/second to increase the degree of supersaturation of solid solution C in the crystal grains, and held in a temperature range of 300 to 500 °C for 3 minutes or more. , a means for obtaining a soft material by diffusing solid solution C into the carbide and grain boundaries within crystal grains, which are the precipitation sites of solid solution C, and promoting precipitation of Pe3C.
（３）さらに深絞り用冷延鋼板の製造に至っては、製鋼
段階であらかじめＣを５０Ｍ以下まで低減させた極低炭
素鋼を素材とし、さらにＴｉ、 Ｎｂ等の炭窒化物形成
元素を添加し、鋼中の固溶Ｃ，Ｎを完全に固定して、完
全非時効性の鋼板とし、さらに延性、絞り性に有効な結
晶粒の成長及び集合組織の形成等を促進するために高温
加熱を行う方法等が用いられていた。(3) Furthermore, when it comes to manufacturing cold-rolled steel sheets for deep drawing, we use ultra-low carbon steel whose C content has been reduced to 50M or less during the steelmaking stage, and further add carbonitride-forming elements such as Ti and Nb. In order to completely fix the solid solution C and N in the steel, making the steel sheet completely non-aging, and further promoting the growth of grains and the formation of texture, which are effective for ductility and drawability, high-temperature heating is applied. The method of doing so was used.
また、（３）の手段のように極低炭素鋼を素材とした鋼
板は、溶鋼コストが高いため高付加価値の鋼板に使用さ
れなければ商業的なメリットはでない。Further, steel plates made of ultra-low carbon steel as in the method (3) have a high cost of molten steel, so they have no commercial advantage unless they are used as high value-added steel plates.
そのため極低炭素鋼を素材とした鋼板をありとあらゆる
種類の冷延鋼板、とくに軽加工用途である低価格の冷延
鋼板に適用することはコスト的に問題があり実用的では
なかった。Therefore, it has been impractical to apply steel sheets made from ultra-low carbon steel to all types of cold-rolled steel sheets, especially low-priced cold-rolled steel sheets for light processing applications, due to cost issues.
以上のようなことから通常の低炭素Ａｌキルド鋼素材・
連続焼鈍法を用いて軟質な冷延鋼板を製造するのは大変
能しいものであった。しかしながら以下に示すような、
低炭素Ａｌキルド鋼素材・連続焼鈍法を用いて軟質な冷
延鋼板を製造する方法が提案されている。すなわち、鋼
中にＢを添加した低炭素Ａ！キルド鋼を用い、連続焼鈍
法で軟質冷延鋼板を製造する方法であるが特開昭５５−
７７９１０号公報、特開昭５６−１３６９５６号公報、
特開昭５６−１４（ｉ８２５号公報、特開昭５６−１５
６７２０号公報、特開昭５６１６６３３０号公報に開示
されているように、熱延巻取温度を６００℃以上の高温
巻取りとし、Ｃ，ＮをＢの析出物として固定し、かつ連
続焼鈍時に２〜３分板上の過時効処理を施すことを特徴
とするものである。From the above, ordinary low carbon Al-killed steel materials
It has been very effective to produce soft cold-rolled steel sheets using the continuous annealing method. However, as shown below,
A method of manufacturing a soft cold-rolled steel sheet using a low-carbon Al-killed steel material and a continuous annealing method has been proposed. In other words, low carbon A with B added to steel! This method uses killed steel to produce soft cold-rolled steel sheets using a continuous annealing method.
Publication No. 77910, Japanese Patent Application Publication No. 136956/1983,
JP-A-56-14 (Publication i825, JP-A-56-15)
As disclosed in Japanese Patent Publication No. 6720 and Japanese Patent Application Laid-open No. 56166330, the hot-rolling temperature is set to 600°C or higher, C and N are fixed as precipitates of B, and 2 It is characterized by performing an over-aging treatment on a plate for ~3 minutes.
しかし、これらは、高温巻取りを要することから前述の
如く脱スケール性に問題が生じるばかりでなく、連続焼
鈍工程においても２分以上の長時間過時効処理時間を行
っていることから、依然として前述の（１）〜（２）の
製造技術の域を脱しておらず製造コストの上昇、操業上
の規制を招いてしまう等の欠点を有している。However, these require high-temperature winding, which not only causes problems in descaling properties as mentioned above, but also requires a long overaging treatment time of 2 minutes or more in the continuous annealing process, so they still remain as described above. However, this technology does not go beyond the manufacturing techniques described in (1) and (2) above, and has drawbacks such as increased manufacturing costs and operational restrictions.
〈発明が解決しようとする課題〉
本発明の目的は、溶鋼コストが比較的低塵な低炭素Ａｌ
キルド鋼を用いて高温巻取を行わず、なおかつ連続焼鈍
中で短時間の過時効処理を施しても耐時効性の良好な冷
延鋼板を製造する方法を提案するものである。<Problems to be Solved by the Invention> The purpose of the present invention is to produce a low-carbon aluminum alloy with relatively low molten steel cost.
The present invention proposes a method for producing cold-rolled steel sheets using killed steel that has good aging resistance even when subjected to short-time overaging treatment during continuous annealing without high-temperature coiling.
く課題を解決するだめの手段〉
本発明は、重量％で、Ｃ＋ ０．０２〜０．０８％、Ｍ
ｎ：０．５％以下、 Ｓ ： ０．００５〜０．０５％
、Ａｌ：ｏ、ｏｔ〜０．２０％、 Ｎ ： ０．００１
０〜０．００５０％、必要に応じてＢ：０．０００１〜
０．００３０％を含有し、残部Ｆｅ及び不可避的ること
を知見したのである。Means for Solving the Problem> The present invention provides C+ 0.02 to 0.08%, M
n: 0.5% or less, S: 0.005-0.05%
, Al: o, ot~0.20%, N: 0.001
0~0.0050%, B: 0.0001~ as necessary
They found that the content was 0.0030%, and the balance was unavoidable.
以下に本発明のちととなった実験及びその結果について
説明をする。The experiments that led to the present invention and their results will be explained below.
〔実験１〕
重量％で、Ｃ： ０．０４２％、 Ｓｉ ： ０．０
１１％、Ｍｎ：０．２７％、 Ｐ ： ０．０１３％、
Ｓ ： ０．０２１％、 ７Ｖ：０９０７８％、 Ｎ
： ０．００３２％を含み、残部Ｆｅ及び不可避的不
純物から成る鋼を実験室で出鋼し、板厚：３０陶のシー
トバーに分塊圧延した後、スラブ加熱温度（ＳＲＴ）に
模して１２５０℃，１０５０’Ｃで１時間加熱し、板厚
： ３．５ｍｍ、仕上温度：８５０℃になるように熱延
した。引き続き、コイル巻取温度（ＣＴ）に模してシー
トバー加熱温度が１０５０℃のものには５５０℃１及び
シートバー加熱温度が１２５０℃のものには５５０℃，
６４０℃の保熱炉に２時間挿入し、その後空冷（冷却速
度：約３℃／分）で室温まで冷却した。[Experiment 1] In weight%, C: 0.042%, Si: 0.0
11%, Mn: 0.27%, P: 0.013%,
S: 0.021%, 7V: 09078%, N
: Steel containing 0.0032% and the balance consisting of Fe and unavoidable impurities was tapped in a laboratory, bloomed into a sheet bar with a thickness of 30 porcelain, and then heated to simulate the slab heating temperature (SRT). It was heated at 1250°C and 1050'C for 1 hour and hot-rolled to a plate thickness of 3.5 mm and a finishing temperature of 850°C. Subsequently, simulating the coil winding temperature (CT), 550°C1 for sheet bar heating temperature of 1050°C, 550°C for sheet bar heating temperature of 1250°C,
It was placed in a heat retention furnace at 640°C for 2 hours, and then cooled to room temperature by air cooling (cooling rate: about 3°C/min).
た。Ta.
酸洗後、圧下率ニア７％の冷間圧延を施し、板厚：０．
８胴の冷延板とした。脱脂後、加熱速度：１５”ｃ／秒
で７５０℃に加熱し、４〜３６秒均熱後、冷却不純物か
らなるスラブを１２００℃以下で加熱し熱間圧延を施し
た後、６００℃以下で巻取り、次いで冷間圧延を施した
後、連続焼鈍法により再結晶温度以上へｃ３変態点以下
の温度域に加熱し１０秒以下の均熱を行った後、２０〜
１００℃／秒の冷却速度で３５０〜５００℃の温度域ま
で冷却し、その温度域に２０〜１２０秒間保持した後、
圧下率１．５〜５．０％の調質圧延を施すことを特徴と
する遅時効性冷延鋼板の製造方法である。After pickling, cold rolling was performed at a rolling reduction of near 7%, and the plate thickness was 0.
It was made into an 8-shell cold-rolled plate. After degreasing, heat to 750°C at a heating rate of 15”c/sec, soak for 4 to 36 seconds, heat the slab consisting of cooled impurities at 1200°C or less, hot roll it, and then heat it at 600°C or less. After winding and then cold rolling, the continuous annealing method was used to heat the recrystallization temperature or higher to the C3 transformation point or lower, and after soaking for 10 seconds or less,
After cooling to a temperature range of 350 to 500 °C at a cooling rate of 100 °C / sec and holding in that temperature range for 20 to 120 seconds,
This is a method for producing a slow-aging cold-rolled steel sheet, which is characterized by performing temper rolling at a rolling reduction of 1.5 to 5.0%.
く作 用〉
本発明者らは、／Ｖ、 Ｎをやや高めにした低炭素Ａｌ
キルド鋼、あるいはそれにＢを添加した鋼板に、スラブ
加熱温度を含む適切な熱延条件を付与することで鋼中の
固溶Ｎを完全にＡＺＮ、あるいはＯＮとして固定し、か
つ連続焼鈍の加熱均熱時間を短くしてカーバイトの再溶
解をできるだけ抑制しておき、さらに過時効処理により
Ａ７Ｎ、 ＢＨの析出物を析出核にして固溶Ｃを析出さ
せ、さらに高圧下率の調質圧延を施して高密度の転位を
付与することで耐時効性の良好な遅時効性冷延鋼板が製
造でき速度ｊ７０℃／秒で４００℃まで急速冷却した後
、４５秒保持し、その後、冷却速度：１０℃／秒で室温
まで冷却するヒートサイクルで再結晶焼鈍を行った。Effect> The present inventors developed a low carbon Al with slightly higher /V and N.
By applying appropriate hot rolling conditions, including slab heating temperature, to killed steel or a steel sheet to which B is added, solid solution N in the steel can be completely fixed as AZN or ON, and heating uniformity during continuous annealing can be achieved. The heating time is shortened to suppress the re-dissolution of carbide as much as possible, and the over-aging treatment is performed to precipitate solid solution C using the precipitates of A7N and BH as precipitation nuclei, followed by temper rolling at a high reduction rate. A slow-aging cold rolled steel sheet with good aging resistance can be produced by imparting high-density dislocations. After rapidly cooling to 400°C at a rate of 70°C/sec, holding for 45 seconds, then cooling rate: Recrystallization annealing was performed by a heat cycle of cooling to room temperature at 10° C./sec.
次いで、圧下率；１．８％の画質圧延を施した後、材料
試験を行い機械的特性、とくに降伏点伸び（Ｙｌｌ）、
時効指数（＾ｇｉｎｇ Ｉｎｄｅｘ ： （１００℃×
３０分時効処理後の降伏点応力） −（７，５％予歪み
時の応力）の絶対値）を調査した。その結果を第１図に
示す。Next, after performing image quality rolling at a reduction rate of 1.8%, material tests were conducted to evaluate mechanical properties, especially elongation at yield (Yll),
Aging Index: (100℃×
The absolute value of (yield point stress after 30 minutes aging treatment) - (stress at 7.5% pre-strain) was investigated. The results are shown in FIG.
その結果、スラブ加熱温度・巻取温度の低い鋼は均熱時
間が１０秒以下の所で急激に降伏点伸びが小さくなり時
効指数は低下した。それに対してスラブ加熱温度・巻取
温度の高い鋼板は硬化し、降伏点伸び１時効指数は大き
くなり材質は劣化した。As a result, for steels with low slab heating and coiling temperatures, the yield point elongation suddenly decreased and the aging index decreased when the soaking time was 10 seconds or less. On the other hand, the steel plate with high slab heating temperature and high coiling temperature became hardened, the yield point elongation 1 aging index increased, and the material quality deteriorated.
また、スラブ加熱温度が高く、巻取温度が低い鋼板は降
伏点伸び１時効指数は共に大きく耐時効性は良くなかっ
た。In addition, steel sheets with a high slab heating temperature and a low coiling temperature had a large yield point elongation 1 aging index and poor aging resistance.
次に降伏点伸び１時効指数におよぼす過時効処理時間の
影響について調査した実験及びその結果について説明す
る。Next, an experiment to investigate the effect of overaging treatment time on the yield point elongation 1 aging index and its results will be explained.
〔実験２〕
重量％で、Ｃ： ０．０４０％、 Ｓｉ ： ０．
００８％、Ｍｎ：０．２３％、 Ｐ ： ０．００
６％、 Ｓ ： ０．０１５％、 ＡＺ ： ０．０
７４％、 Ｎ ： ０．００３６％を含め、残部ｒｅ及
び不可避的不純物から成る鋼を実験室で出鋼し、板厚：
３０鴫のシートバーに分塊圧延した後、１０５０℃で１
時間加熱し、板］！ｉＥ： ３．５ｍｍ、仕上温度：
８５０℃になるように熱延した。引き続き、５５０℃の
保熱炉に２時間挿入し、その後空冷（冷却速度：約３℃
／分）で室温まで冷却した。[Experiment 2] In weight %, C: 0.040%, Si: 0.
008%, Mn: 0.23%, P: 0.00
6%, S: 0.015%, AZ: 0.0
Steel consisting of 74%, N: 0.0036%, the balance re and unavoidable impurities was tapped in a laboratory, and the plate thickness:
After blooming into a 30mm sheet bar, it was rolled at 1050℃.
Heat for an hour and board]! iE: 3.5mm, finishing temperature:
It was hot rolled to 850°C. Subsequently, it was placed in a heat retention furnace at 550°C for 2 hours, and then air cooled (cooling rate: approximately 3°C).
/min) to room temperature.
酸洗後、圧下率ニア７％の冷間圧延を施し、板厚：
０．８ｍｍの冷延板とした。脱脂後、加熱速度：１５”
Ｃ／秒で７２０℃に加熱し、２秒間又は３０秒間均熱し
、冷却速度−６０℃／秒で４２０℃まで栄、速冷却した
後、４〜１６０秒保持し、その後、冷却速度：８℃／秒
で室温まで冷却するヒートサイクルで再結晶焼鈍を行っ
た。次いで、圧下率：２．５％の調質圧延を施した後、
材料試験を行い、降伏点伸び（Ｙ ＩＥ ｆ ） 、時
効指数（ＡｇｉｎｇＩｎｄｅｘ ： （１００℃×３０
分時効処理後の降伏点応力） −（７，５％予歪み冷却
した後、４０秒保持して、その後冷却速度：８”Ｃ／秒
で室温まで冷却するヒートサイクルで再結晶焼鈍を行っ
た。After pickling, cold rolling was performed at a rolling reduction of near 7%, and the plate thickness:
It was made into a cold-rolled plate of 0.8 mm. After degreasing, heating rate: 15”
Heated to 720°C at a rate of C/sec, soaked for 2 seconds or 30 seconds, cooled quickly to 420°C at a cooling rate of -60°C/sec, held for 4-160 seconds, then cooled at a rate of 8°C. Recrystallization annealing was performed using a heat cycle in which the sample was cooled to room temperature at a rate of 1/2 seconds. Next, after skin pass rolling with a rolling reduction ratio of 2.5%,
Material tests were conducted to determine yield point elongation (Y IE f ) and aging index (AgingIndex: (100°C x 30°C).
(yield point stress after aging treatment) - (7.5% prestrain After cooling, holding for 40 seconds, then recrystallization annealing was performed by a heat cycle of cooling to room temperature at a cooling rate of 8"C/sec. .
次いで、圧下率：２．０％の調質圧延を施した後、これ
らの鋼板の降伏点伸び、降伏点について調査し、その結
果を第３図に示した。これによればＢ量が増大するにし
たがい降伏点が低下し、降伏点伸びが小さくなる傾向に
ある。しかし３０騨超になると降伏点が高くなる傾向に
ある。従って最適Ｂ量は０．０００１〜０．００３０％
で、これらの範囲で耐時効性は良好であることが判明し
た。Next, after skin pass rolling at a rolling reduction of 2.0%, the yield point elongation and yield point of these steel plates were investigated, and the results are shown in FIG. According to this, as the amount of B increases, the yield point decreases and the yield point elongation tends to decrease. However, when the value exceeds 30, the yield point tends to increase. Therefore, the optimal amount of B is 0.0001 to 0.0030%
It was found that the aging resistance was good within these ranges.
本実験において、Ｂを添加し、短時間の過時効処理を行
った鋼板の降伏点伸びが小さく、時効指数が顕著に低く
なった理由としては、Ｂが添加されることにより結晶粒
径が微細化され固溶Ｃが結晶粒界へ析出しやすくなった
こと、及びＩＩＮが析出していることで鋼中の固ｔｆｕ
Ｊが固定されていること、ならびにＢＮとＦｅＢ （Ｃ
，Ｂ）と考えられる析出物が固溶Ｃの析出ザイトとなり
カーバイトの析出（固溶Ｃが減少）を促進し耐時効性が
改善され時の応力）の絶対値）を調査した。その結果を
第２図に示す。In this experiment, the yield point elongation of the steel sheet that was subjected to short-time overaging treatment with the addition of B was small, and the aging index was noticeably low. The solid solution C becomes more likely to precipitate to the grain boundaries, and the precipitation of IIN reduces the solid TFU in the steel.
J is fixed, and BN and FeB (C
, B) The precipitates that are considered to be precipitated zite of solid solute C promote the precipitation of carbide (reduction of solid solute C), and the aging resistance is improved. The results are shown in FIG.
その結果、均熱時間が２秒の鋼は過時効時間が２０秒以
上であれば短時間の過時効処理でも降伏点伸びが小さく
、八戸は低めであった。しかし均熱時間が３０秒の鋼は
これに対して過時効時間が１２０秒以上にならない限り
降伏点伸びは大きく、＾、■。As a result, steel with a soaking time of 2 seconds had a small yield point elongation even after a short overaging treatment if the overaging time was 20 seconds or more, and Hachinohe had a lower elongation. However, steel with a soaking time of 30 seconds has a large yield point elongation unless the overaging time is 120 seconds or more.
は高めであった。was high.
次に、＋Ａ質におよぼすＢ添加量の調査を行った実験及
びその結果について説明する。Next, an experiment conducted to investigate the amount of B added to +A quality and its results will be explained.
〔実験３〕
重量％で、Ｃ： ０．０４３％、 Ｓｉ ： ０．
０１０％、Ｍｎ：０．３１％、 Ｐ ： ０．００
６％、 Ｓ ：０．０２３％、 ／Ｖ ： ０．０６
９％、 Ｎ ： ０．００４１％を基本成分とし、Ｂを
ｏ、ｏｏｏ６゜０．００１５．０．００２５．０．００
４０％添加した鋼を実験室で出鋼し、〔実験２〕と同じ
工程条件で板厚：３．５ｍｍの熱延板とした。酸洗後、
圧下率ニア７％の冷間圧延を施し、板厚： ０．８ｍ
ｍの冷延板とした。脱脂後、加熱速度：１５℃／秒で７
２０℃に加熱し、１秒間均熱し、冷却速度：５０′Ｃ／
秒で３８０℃まで急速ＩまＩま
たためと考えられる。またさらに、調質圧延圧下率を２
．０％と通常に比べてやや高めの圧下率としたため転位
密度が高くなり、固溶元素がトラップされ時効性がさら
に改善されたためと考えられる。[Experiment 3] In weight %, C: 0.043%, Si: 0.
010%, Mn: 0.31%, P: 0.00
6%, S: 0.023%, /V: 0.06
9%, N: 0.0041% as the basic component, B as o, ooo6゜0.0015.0.0025.0.00
Steel with 40% addition was tapped in a laboratory and made into a hot rolled sheet with a thickness of 3.5 mm under the same process conditions as [Experiment 2]. After pickling,
Cold rolled with a rolling reduction of near 7%, plate thickness: 0.8m
It was made into a cold-rolled sheet of m. After degreasing, heating rate: 7 at 15°C/sec
Heat to 20℃, soak for 1 second, cooling rate: 50'C/
It is thought that this is because the temperature rises rapidly to 380°C in seconds. Furthermore, the temper rolling reduction rate is set to 2.
．． It is thought that this is because the rolling reduction rate was set at 0%, which was a little higher than usual, so the dislocation density became high, solid solution elements were trapped, and the aging property was further improved.
次に、材質と４に耐時効性に及ぼす調質圧延の圧下率の
影響について調査した実験及びその結果について説明す
る。Next, an experiment conducted to investigate the influence of the rolling reduction of skin pass rolling on material quality and aging resistance (4) and its results will be explained.
〔実験４〕
重量％で、Ｃ： ０．０３４％、 Ｓｉ ： ０．
０１１％、Ｍｎ：０．２０％、 Ｐ ： ０．００
７％、 Ｓ ： ０．００６％、 Ａｌ ： ０．０
８３％、 Ｎ ： ０．００３４％、 Ｂ ： ０．０
０１３％を基本組成とした鋼を実験室で出鋼し、〔実験
３〕と同じ工程条件で冷延焼鈍板とした。圧下率：ｏ、
４＋ ０．８．１．５゜３．０．５．０．７．０％の調
質圧延を施した後、これらの鋼板の降伏点、降伏点伸び
、全伸び（Ｅ７）、時効指数について調査し、その結果
を第４図に示した。この結果によればＢを添加した鋼で
も圧下率：１．５％未満では時効性の改善効果がなかっ
た。[Experiment 4] In weight %, C: 0.034%, Si: 0.
011%, Mn: 0.20%, P: 0.00
7%, S: 0.006%, Al: 0.0
83%, N: 0.0034%, B: 0.0
Steel having a basic composition of 0.013% was tapped in the laboratory and made into cold rolled annealed sheets under the same process conditions as [Experiment 3]. Rolling reduction rate: o,
4+ About the yield point, yield point elongation, total elongation (E7), and aging index of these steel plates after temper rolling of 0.8.1.5°3.0.5.0.7.0% The results are shown in Figure 4. According to the results, even steel to which B was added had no effect of improving aging properties when the rolling reduction was less than 1.5%.
また圧下率＝５．０％超では降伏点が上昇し材質（Ｕ）
は硬化してしまった。In addition, when the rolling reduction rate exceeds 5.0%, the yield point increases and the material (U)
has hardened.
以上の実験結果から本発明は構成されたものであり、必
要に応してａｍのＢを添加した鋼を用い、熱延条件、連
続焼鈍条件、調質圧延条件を規制することで本発明のよ
うな耐時効性の良好な冷延鋼板が製造することができる
。The present invention has been constructed based on the above experimental results, and by using steel to which am B is added as necessary and regulating hot rolling conditions, continuous annealing conditions, and skin pass rolling conditions, the present invention can be achieved. A cold-rolled steel sheet with good aging resistance can be produced.
次に、本発明における成分及び製造条件を限定した理由
について以下に説明する。Next, the reasons for limiting the components and manufacturing conditions in the present invention will be explained below.
ＣＴＣは、侵入型固溶元素であり、０．０８％超の含有
は結晶粒を微細化し、材質を硬化させてしまうので上限
を０．０８％とした。しかし、０．０２％未満の含有量
の場合、結晶粒が比較的大きくなり、連続焼鈍の急冷・
過時効処理で固溶Ｃの析出が起こりにくくなるため下限
を０．０２％とした。CTC is an interstitial solid solution element, and its content exceeding 0.08% will make the crystal grains finer and harden the material, so the upper limit was set at 0.08%. However, if the content is less than 0.02%, the crystal grains become relatively large, resulting in rapid cooling during continuous annealing.
The lower limit was set at 0.02% because precipitation of solid solution C becomes less likely to occur during overaging treatment.
Ｍｎ ： Ｍｎは、赤熱脆性の原因となるＳをＭｎＳと
して固定するのに必要な元素であるが、０．５％超の含
有は、材質を硬化させ、延性を低下させ′ζしまうこと
から、本発明の上限を０．５％とした。Mn: Mn is an element necessary to fix S, which causes red-hot brittleness, as MnS, but if it is contained in an amount exceeding 0.5%, it will harden the material and reduce its ductility. The upper limit of the present invention is set to 0.5%.
ＳＯ３は、通常材質を劣化させることから少ないほうが
好ましいが、本発明では連続焼鈍中のカーバイトの析出
を促進さ一辻るサイトを形成するたでき、ＯＮとしてＮ
を固定する他にカーバイトの析出サイトを形成すること
から有効な元素である。Normally, SO3 deteriorates the material, so it is preferable to reduce the amount of SO3, but in the present invention, it can promote the precipitation of carbide during continuous annealing and form a continuous site.
In addition to fixing carbide, it is an effective element because it forms carbide precipitation sites.
その効果を引き出すには、少なくとも０．０００１％の
含有が好ましい。しかしながら、多量の含有とくに０．
００３０％超の含有は材質を劣化させてしまうことがら
Ｂの含有量を０．０００１〜０．００３０％とした。In order to bring out the effect, the content is preferably at least 0.0001%. However, it contains a large amount, especially 0.
Since the content of B exceeding 0.030% deteriorates the material, the content of B was set to 0.0001 to 0.0030%.
その他、不可避的不純物として含有される元素について
は、とくに規定はしないが、その含有は極力低く抑える
のが好ましい。Other elements contained as unavoidable impurities are not particularly specified, but it is preferable to keep their content as low as possible.
スラブ加熱温度ニスラブ加熱温度を１２００’ｃ以下と
した理由は、スラブ鋳込み後の冷却過程で粗大に析出し
たＭｎＳ、 ＢＨ，ＡｆＮ等の析出物を再溶解させない
ようにするためである。これらの粗大な析出物は冷延・
連続焼鈍時の過時効処理でカーバイトの析出を促進し材
質を軟質化することができるからである。Slab Heating Temperature The reason why the slab heating temperature is set to 1200'C or less is to prevent precipitates such as MnS, BH, AfN, etc., which have coarsely precipitated during the cooling process after slab casting, from being redissolved. These coarse precipitates are removed by cold rolling.
This is because the overaging treatment during continuous annealing can promote the precipitation of carbide and soften the material.
熱延仕上温度：通常、プレス成形性の良好な冷延鋼板を
製造する場合には、＾ｒ３変態点以上とする必要がある
が、単に軽加工用の軟質な冷延鋼板を製造する目的であ
れば＾ｒ、変態点以下の温度でめ、積極的にＭｎＳを析
出させることから、少なくても０．００５％は必要であ
る。しかし、０．０５％超の含有は、必然的にＭｎ量を
増大させてしまい、コストの上昇、材質の劣化を招いて
しまう。よって本発明では０．００５〜０．０５０％に
限定した。Hot-rolling finishing temperature: Normally, when producing cold-rolled steel sheets with good press formability, it is necessary to set the temperature to ^r3 transformation point or higher, but for the purpose of simply producing soft cold-rolled steel sheets for light processing. If present, at least 0.005% is necessary since MnS is actively precipitated at a temperature below the transformation point. However, a content of more than 0.05% inevitably increases the amount of Mn, leading to an increase in cost and deterioration of material quality. Therefore, in the present invention, the content is limited to 0.005 to 0.050%.
Ａｌ：Ａ１は、製鋼段階で脱酸剤として使用される他、
鋼中のＮをＡＺＮとして固定する元素であることから、
少なくても０．０１％の含有は必要である。Al: A1 is used as a deoxidizing agent in the steel manufacturing stage, and
Since it is an element that fixes N in steel as AZN,
It is necessary to contain at least 0.01%.
しかしながら、ＡＩは高価な元素であり、０．２０％超
の含有はコスト高となることから本発明では０．０１〜
０．２０％に限定した。However, AI is an expensive element, and if the content exceeds 0.20%, the cost will be high.
It was limited to 0.20%.
ＮＵＮは、Ｃと同様に侵入型固溶元素であり材質を劣化
させるので、通常は極力少ない方が好ましい。本発明で
は、Ａｌを添加して熱延条件を制御することでＡＩＭを
析出させ、これをカーバイトの析出サイトとすることか
ら、少なくとも０．００１０％の含有は必要である。し
かし、０．００５０％超の含有は材質を著しく劣化させ
てしまうことから本発明ではＮの含有量を０．００１０
〜０．００５０％に限定した。Like C, NUN is an interstitial solid solution element and degrades the material, so it is usually preferable to have as little amount as possible. In the present invention, AIM is precipitated by adding Al and controlling the hot rolling conditions, and this is used as a carbide precipitation site, so it is necessary to contain at least 0.0010%. However, if the N content exceeds 0.0050%, the material deteriorates significantly, so in the present invention, the N content is reduced to 0.0010%.
It was limited to ~0.0050%.
ＢＩＢは、本発明にとっては必要に応じて添加熱延を終
了してもなんら問題はない。よって本発明においてはと
くに熱延仕上温度に関して規制はしない。For the present invention, there is no problem in BIB even if addition hot rolling is terminated as necessary. Therefore, in the present invention, there is no particular restriction regarding the hot rolling finishing temperature.
巻取温度：本発明では高温にするほど材質が良好となる
が、６００℃超にした場合、材質の良好な鋼板を製造す
るには有利であるが酸化膜が厚くなり、脱スケール性が
悪くなる他、熱延コイルの幅方向・内径方向での均熱む
らが生じ、コイル内での材質の均質性が悪くなる等の問
題がある。よって本発明での上限を６００℃とした。Coiling temperature: In the present invention, the higher the temperature, the better the quality of the material, but if the temperature is higher than 600°C, it is advantageous for producing a steel plate with good quality, but the oxide film becomes thicker and the descaling performance is poor. In addition, there are other problems such as uneven heating in the width direction and inner diameter direction of the hot rolled coil, resulting in poor material homogeneity within the coil. Therefore, the upper limit in the present invention is set to 600°C.
連続焼鈍法：本発明で再結晶焼鈍に連続焼鈍法を適用し
た理由は、従来の箱焼鈍法では製造日数が非常にかかる
上、なおかつコイル内の材質が均質なものを製造するの
が困難である。しかしながら連続焼鈍を適用することで
これらの問題を解決することが可能であるからである。Continuous annealing method: The reason why the continuous annealing method is applied to recrystallization annealing in the present invention is that the conventional box annealing method takes a very long manufacturing time and is difficult to manufacture a coil with a homogeneous material. be. However, these problems can be solved by applying continuous annealing.
また加熱温度を再結晶温度以上、Ａｃ３変態点以下の温
度域にした理由は、再結晶温度未満の温度では加工性が
著しく劣り加工が困難であるからであり、また胱。Further, the reason why the heating temperature is set to a temperature range above the recrystallization temperature and below the Ac3 transformation point is that at a temperature below the recrystallization temperature, workability is extremely poor and processing is difficult.
変態点超の高温に加熱した場合、ＡＩＮが分解し固溶Ｎ
Ｉが増大し材質が劣化するからである。また、均熱時間
が１０秒以下の場合は冷延前に析出したカーバイトの再
固溶が抑制され、固Ｉｃ量をできるだけ減少させておく
ことが可能である。そのため均熱時間は１０秒以内とす
る必要がある。もちろん０秒でもよい。その後の冷却速
度を２０−１００℃／秒とした理由は、２０℃／秒未満
の冷却速度では結晶粒内に固１ｃを過飽和にすることが
できないためであり、また１００℃／秒超の冷却速度に
するには設備的に回能であるからである。さらに、３５
０〜５００℃の温度域まで冷却し２０〜１２０秒保持す
るのは、この温度域で最もＣが析出サイトである結晶粒
界まで拡散しやすいことからである。また、それに要す
る時間は最低限２０秒必要である。しかし、１２０秒超
０保持はラインスピードを規制し、生産性を低下させる
か、もしくは長大な過時効処理設備を必要とすることか
らこの温度域での滞留時間を２０〜１２０秒とした。When heated to a high temperature exceeding the transformation point, AIN decomposes and forms solid solution N.
This is because I increases and the material quality deteriorates. Further, when the soaking time is 10 seconds or less, re-solid solution of carbide precipitated before cold rolling is suppressed, and it is possible to reduce the amount of solid Ic as much as possible. Therefore, the soaking time must be within 10 seconds. Of course, it may be 0 seconds. The reason why the subsequent cooling rate was set to 20-100℃/sec is that it is not possible to supersaturate solid 1c in the crystal grains with a cooling rate of less than 20℃/sec. This is because it takes a lot of equipment to increase speed. Furthermore, 35
The reason why it is cooled to a temperature range of 0 to 500°C and held for 20 to 120 seconds is because in this temperature range C is most likely to diffuse to the grain boundaries, which are precipitation sites. Further, the time required for this is at least 20 seconds. However, holding the temperature at zero for more than 120 seconds restricts the line speed, reduces productivity, or requires extensive overaging treatment equipment, so the residence time in this temperature range was set to 20 to 120 seconds.
調質圧延圧下率：圧下率を１．５〜５．０％とした理由
は、鋼中の固１ｃ、Ｎを固定するに必要な転験を行い機
械的特性１時効指数〔八ｇｉｎｇ Ｉｎｄｅｘ ：（１
００℃×３０分時効処理後の降伏点応力） −（７，５
％予歪み時の応力）の絶対値〕を調査した。その結果を
第３表に示した。Temper rolling reduction ratio: The reason why the reduction ratio was set to 1.5 to 5.0% is that the necessary rolling tests were carried out to fix the hardness and N in the steel, and the mechanical properties were determined by aging index. (1
Yield point stress after aging treatment at 00°C for 30 minutes) −(7,5
% stress at prestrain)] was investigated. The results are shown in Table 3.
その結果、本発明の化学組成、製造方法で製造された鋼
板は低炭素Ａ！キルド鋼で過時効処理時間が短くても十
分に降伏伸びが小さく、耐時効性は良好であった。それ
に対して本発明外の比較鋼は、時効性が悪かった。As a result, the steel sheet manufactured using the chemical composition and manufacturing method of the present invention has a low carbon A! Even with a short overaging treatment time for killed steel, the yield elongation was sufficiently small and the aging resistance was good. In contrast, comparative steels other than those of the present invention had poor aging properties.
位を導入し、降伏伸びを抑制するには最低限１．５％の
圧下率の調質圧延を施す必要があり、これ以下の圧下率
での転位の導入では時効じやすくなってしまうからであ
る。しかし、５．０％超の圧下率では、材質が硬化し過
ぎ、とくに降伏点が高く、全伸びが低下してしまうから
である。In order to introduce dislocations and suppress yield elongation, it is necessary to perform skin pass rolling with a reduction ratio of at least 1.5%, as introducing dislocations at a reduction ratio lower than this will cause aging. be. However, if the rolling reduction exceeds 5.0%, the material will harden too much, resulting in a particularly high yield point and a decrease in total elongation.
次に実施例について説明をする。Next, an example will be explained.
〈実施例〉
第１表に示したような化学組成の連続鋳造スラブを１０
００〜１２７０℃で１時間加熱し、熱間圧延で板厚：
３．５ｍｍ、仕上げ温度ニア４０〜８７０′ｃニなるよ
うに圧延した。引き続き、５２０〜６３０℃の巻取温度
で巻取り熱延コイルとした。<Example> 10 continuous cast slabs with the chemical composition shown in Table 1 were
Heating at 00-1270℃ for 1 hour and hot rolling the plate thickness:
It was rolled to a thickness of 3.5 mm and a finishing temperature of 40 to 870'C. Subsequently, the coil was wound into a hot-rolled coil at a winding temperature of 520 to 630°C.
酸洗後、冷間圧延で板厚： ０．８ｍｍの冷延板とした
。その後、加熱速度：１０℃／秒で第２表に示したよう
に再結晶温度以上胱、変態点以下の焼鈍温度×時間、冷
却速度、過時効温度Ｘ時間を行った後、冷却速度：８℃
／秒で室温まで冷却するヒートサイクルで再結晶焼鈍を
行った。次いで、圧下率：１．５〜４．０％の調質圧延
を施した後、材料状ｅ囮
亦暉。After pickling, the sample was cold rolled into a cold rolled plate having a thickness of 0.8 mm. Thereafter, as shown in Table 2 at a heating rate of 10°C/sec, the temperature is higher than the recrystallization temperature, the annealing temperature is lower than the transformation point x time, the cooling rate is over-aging temperature x hours, and the cooling rate is 8 ℃
Recrystallization annealing was performed using a heat cycle in which the sample was cooled to room temperature at a rate of 1/2 seconds. Then, after being subjected to temper rolling at a rolling reduction ratio of 1.5 to 4.0%, the material state is e-decoy.
○
○
○
ｆｌｉ！倒
倚禦
ド
〜
〜
〜
〜
１“
口
安
巴
慧
＝
宍
皮
安
ば
＝
〈発明の効果〉
本発明により、低炭素Ａｌキルド鋼に短時間過時効処理
の連続焼鈍を施すことにより、遅時効性の冷延鋼板を製
造することができるようになった。○ ○ ○ fli! 1" Tomoe Kuchiyasu = Yasuba Shishipi = <Effects of the Invention> According to the present invention, low-carbon Al-killed steel is subjected to continuous annealing with short-time overaging treatment, thereby achieving slow aging. It is now possible to produce cold-rolled steel sheets of high quality.
またこの技術を適用すれば連続焼鈍のラインスピードを
高速とすることが可能であり、生産性を一層向上させる
ことができる。Moreover, if this technology is applied, it is possible to increase the line speed of continuous annealing, and productivity can be further improved.
第１図は、降伏点伸び（ＹＥＩ！、）、時効指数（Ａ、
１． ： Ａｇｉｎｇ Ｉｎｄｅｘ）に及ぼずスラブ
加熱温度。
巻取温度、均熱時間の影響を示す図、第２図は、降伏点
伸び（ＹＥ／り、時効指数（＾、１、： 八ｇｉｎｇＩ
ｎｄｅχ）に及ぼす均熱時間、過時効時間の影響を示す
図、第３図は、降伏点伸び（ＹＥｌ）、Ｉｌｌ伏点（Ｙ
Ｐ）に及ばずＢ量の影響を示す図、第４図は、降伏点（
ＹＰ）、降伏点伸び（ＹＥｆｆｉ）、全伸び（ＥＩ！、
）、時効指数（＾、１． ： Ａｇｉｎｇ Ｉｎｄｅｘ
）に及ぼす調質圧延圧下率の影響を示す図である。
特許出願人 川崎製鉄株式会社
第２
第
図Figure 1 shows yield point elongation (YEI!), aging index (A,
1. : Slab heating temperature that does not reach Aging Index). Figure 2 shows the effects of coiling temperature and soaking time.
Figure 3 shows the effects of soaking time and overaging time on yield point elongation (YEl) and Ill yield point (Y
Figure 4 shows the influence of B amount on yield point (P).
YP), elongation at yield point (YEffi), total elongation (EI!,
), Aging Index (^, 1.: Aging Index
) is a diagram showing the influence of temper rolling reduction rate on Patent applicant: Kawasaki Steel Corporation Figure 2
Claims (1)
５％以下、５：０．００５〜０．０５％、Ａｌ：０．０
１〜０．２０％、Ｎ：０．００１０〜０．００５０％を
含有し、残部Ｆｅ及び不可避的不純物からなるスラブを
１２００℃以下で加熱し熱間圧延を施した後、６００℃
以下で巻取り、次いで冷間圧延を施した後、連続焼鈍法
により再結晶温度以上Ａｃ＿３変態点以下の温度域に加
熱し１０秒以下の均熱を行った後、２０〜１００℃／秒
の冷却速度で３５０〜５００℃の温度域まで冷却し、そ
の温度域に２０〜１２０秒間保持した後、圧下率１．５
〜５．０％の調質圧延を施すことを特徴とする遅時効性
冷延鋼板の製造方法。 ２、重量％で、Ｃ：０．０２〜０．０８％、Ｍｎ：０．
５％以下、Ｓ：０．００５〜０．０５％、Ａｌ：０．０
１〜０．２０％、Ｎ：０．００１０〜０．００５０％、
Ｂ：０．０００１〜０．００３０％を含有し、残部Ｆｅ
及び不可避的不純物からなるスラブを１２００℃以下で
加熱し熱間圧延を施した後、６００℃以下で巻取り、次
いで冷間圧延を施した後、連続焼鈍法により再結晶温度
以上Ａｃ＿３変態点以下の温度域に加熱し１０秒以下の
均熱を行った後、２０〜１００℃／秒の冷却速度で３５
０〜５００℃の温度域まで冷却し、その温度域に２０〜
１２０秒間保持した後、圧下率１．５〜５．０％の調質
圧延を施すことを特徴とする遅時効性冷延鋼板の製造方
法。[Claims] 1. In weight%, C: 0.02 to 0.08%, Mn: 0.
5% or less, 5:0.005-0.05%, Al:0.0
A slab containing 1 to 0.20% of N, 0.0010 to 0.0050% of N, and the balance consisting of Fe and unavoidable impurities was heated at 1200°C or lower and hot rolled, and then heated to 600°C.
After being coiled and then cold rolled, heated to a temperature range from recrystallization temperature to Ac_3 transformation point by continuous annealing method, soaked for 10 seconds or less, and then heated at 20 to 100℃/second. After cooling to a temperature range of 350 to 500°C at a cooling rate and holding in that temperature range for 20 to 120 seconds, the reduction rate is 1.5.
A method for producing a slow-aging cold-rolled steel sheet, characterized by subjecting it to temper rolling of ~5.0%. 2. In weight%, C: 0.02-0.08%, Mn: 0.
5% or less, S: 0.005-0.05%, Al: 0.0
1 to 0.20%, N: 0.0010 to 0.0050%,
B: Contains 0.0001 to 0.0030%, balance Fe
After heating and hot rolling a slab consisting of unavoidable impurities at a temperature below 1200°C, coiling it at a temperature below 600°C, and then cold rolling, a continuous annealing method is used to reduce the temperature to a temperature above the recrystallization temperature and below the Ac_3 transformation point. After heating to a temperature range of 10 seconds or less, cooling at a cooling rate of 20 to 100 degrees Celsius/second
Cool to a temperature range of 0 to 500℃, and cool to a temperature range of 20 to 500℃.
A method for producing a slow-aging cold-rolled steel sheet, which comprises holding the steel sheet for 120 seconds and then subjecting it to temper rolling at a reduction rate of 1.5 to 5.0%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63292361A JPH07100817B2 (en) | 1988-11-21 | 1988-11-21 | Method for manufacturing slow-aging cold-rolled steel sheet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63292361A JPH07100817B2 (en) | 1988-11-21 | 1988-11-21 | Method for manufacturing slow-aging cold-rolled steel sheet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02141534A true JPH02141534A (en) | 1990-05-30 |
| JPH07100817B2 JPH07100817B2 (en) | 1995-11-01 |
Family
ID=17780809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63292361A Expired - Fee Related JPH07100817B2 (en) | 1988-11-21 | 1988-11-21 | Method for manufacturing slow-aging cold-rolled steel sheet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07100817B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008063619A (en) * | 2006-09-07 | 2008-03-21 | Nippon Steel Corp | Steel sheet for side seamless can, and its production method |
| CN114107623A (en) * | 2021-12-01 | 2022-03-01 | 安徽工业大学 | Heat treatment method for reducing aging property of SPHC hot rolled plate coil through online isothermal de-aging annealing |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS48100314A (en) * | 1972-04-03 | 1973-12-18 | ||
| JPS6389625A (en) * | 1986-10-01 | 1988-04-20 | Kawasaki Steel Corp | Production of extremely thin steel sheet having good flange workability |
-
1988
- 1988-11-21 JP JP63292361A patent/JPH07100817B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS48100314A (en) * | 1972-04-03 | 1973-12-18 | ||
| JPS6389625A (en) * | 1986-10-01 | 1988-04-20 | Kawasaki Steel Corp | Production of extremely thin steel sheet having good flange workability |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008063619A (en) * | 2006-09-07 | 2008-03-21 | Nippon Steel Corp | Steel sheet for side seamless can, and its production method |
| CN114107623A (en) * | 2021-12-01 | 2022-03-01 | 安徽工业大学 | Heat treatment method for reducing aging property of SPHC hot rolled plate coil through online isothermal de-aging annealing |
| CN114107623B (en) * | 2021-12-01 | 2023-09-15 | 安徽工业大学 | Heat treatment method for reducing timeliness of SPHC hot rolled plate coil by online isothermal aging removal annealing |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07100817B2 (en) | 1995-11-01 |
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