JP2546889B2 - Dimension control method of thick steel plate for quenching and tempering - Google Patents
Dimension control method of thick steel plate for quenching and temperingInfo
- Publication number
- JP2546889B2 JP2546889B2 JP1037082A JP3708289A JP2546889B2 JP 2546889 B2 JP2546889 B2 JP 2546889B2 JP 1037082 A JP1037082 A JP 1037082A JP 3708289 A JP3708289 A JP 3708289A JP 2546889 B2 JP2546889 B2 JP 2546889B2
- Authority
- JP
- Japan
- Prior art keywords
- quenching
- tempering
- cutting
- thick steel
- width
- 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.)
- Expired - Lifetime
Links
- 238000010791 quenching Methods 0.000 title claims description 50
- 230000000171 quenching effect Effects 0.000 title claims description 47
- 229910000831 Steel Inorganic materials 0.000 title claims description 27
- 239000010959 steel Substances 0.000 title claims description 27
- 238000005496 tempering Methods 0.000 title claims description 26
- 238000000034 method Methods 0.000 title claims description 20
- 238000005520 cutting process Methods 0.000 claims description 23
- 238000005096 rolling process Methods 0.000 claims description 14
- 238000010438 heat treatment Methods 0.000 claims description 10
- 239000000126 substance Substances 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 6
- 229910000975 Carbon steel Inorganic materials 0.000 claims description 4
- 239000010962 carbon steel Substances 0.000 claims description 4
- 229910000851 Alloy steel Inorganic materials 0.000 claims description 3
- 239000000463 material Substances 0.000 description 10
- 238000012733 comparative method Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 238000005422 blasting Methods 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
- B21B1/38—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling sheets of limited length, e.g. folded sheets, superimposed sheets, pack rolling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B3/00—Rolling materials of special alloys so far as the composition of the alloy requires or permits special rolling methods or sequences ; Rolling of aluminium, copper, zinc or other non-ferrous metals
- B21B3/02—Rolling special iron alloys, e.g. stainless steel
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Control Of Metal Rolling (AREA)
- Metal Rolling (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、焼入焼戻を実施する厚鋼板の製造に係り、
更に詳しくは、焼入焼戻を実施する厚鋼板を圧延及び焼
入前切断で寸法制御して、寸法精度及び歩留・切断作業
性を改善する寸法制御法に関するものである。DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to the manufacture of a thick steel plate for quenching and tempering,
More specifically, the present invention relates to a dimensional control method for improving the dimensional accuracy and the yield / cutting workability by controlling the dimensions of a thick steel plate to be quenched and tempered by rolling and cutting before quenching.
（従来の技術及び解決しようとする課題） 従来より、焼入焼戻を実施する厚鋼板は、焼入焼戻に
より板厚が減少し、幅・長さが増加することが知られて
いた。すなわち、板厚が減少する原因は焼入前のショッ
トブラストと焼入・焼戻の２回加熱によるものとされ、
一方、幅・長さが増加する原因はマルテンサイト変態膨
張によるものとされていた。(Prior Art and Problems to Be Solved) It has been conventionally known that a thick steel plate subjected to quenching and tempering has a reduced thickness and an increased width / length due to quenching and tempering. That is, the cause of the decrease in sheet thickness is considered to be shot blasting before quenching and two heatings of quenching and tempering,
On the other hand, the cause of the increase in width and length was considered to be due to martensitic transformation expansion.
このため、製品の寸法に関するバラツキが大きく、ま
た、これをカバーするために非熱処理材に比べて大きい
素材を必要とし、歩留（製品重量／素材重量）を低下さ
せていた。For this reason, there are large variations in product dimensions, and a material larger than the non-heat-treated material is required to cover this, resulting in a reduction in yield (product weight / material weight).
したがって、従来の上記焼入焼戻材の寸法制御に関し
ては、前述の如く非焼入焼戻材に比べて寸法に関する品
質や歩留が悪い上、幅・長さのバラツキが大きいことか
ら、焼入前に炉内ローラの保護のための圧延クロップ切
断（仮切断）を経て、焼入焼戻後に製品切断されてお
り、このため、切断作業性も阻害させていた。Therefore, regarding the dimensional control of the above-mentioned quenched and tempered material, as described above, since the quality and yield related to the dimension are worse than the non-quenched and tempered material, and the variation in width and length is large, Rolling crop cutting (temporary cutting) for protection of the in-furnace roller was performed before the product was put in, and the product was cut after quenching and tempering. Therefore, cutting workability was also hindered.
一方、厚板分野では、計算重量で取引されているこ
と、需要家より構造物にした時の重量精度向上や切断作
業の合理化のための厳格寸法の要求が増加していること
から、増々寸法精度の向上が必要となってきている。On the other hand, in the field of thick plates, the size is increasing more and more due to the fact that it is traded with calculated weight and the demand for strict dimensions from the customer to improve the weight accuracy when making a structure and to rationalize the cutting work. It is necessary to improve accuracy.
本発明は、かゝる要請に応えるべくなされたものであ
って、焼入焼戻を実施する厚鋼板を製造するに際し、寸
法精度及び歩留、切断作業性を向上し得る寸法制御方法
を提供することを目的とするものである。The present invention has been made in response to such a request, and provides a dimensional control method capable of improving dimensional accuracy, yield, and cutting workability when manufacturing a thick steel plate for quenching and tempering. The purpose is to do.
（課題を解決するための手段） 前記目的を達成するため、本発明者は、焼入焼戻を実
施する厚鋼板を製造する場合に非焼入焼戻材に比べて寸
法に係る品質及び歩留、切断作業性が劣る原因を究明す
るとと共に、その対策について鋭意研究と検討を重ね
た。(Means for Solving the Problem) In order to achieve the above-mentioned object, the present inventor, when manufacturing a thick steel sheet for carrying out quenching and tempering, has the quality and the step related to the dimension as compared with the non-quenching and tempering material. In addition to investigating the cause of the poor retention and cutting workability, we also conducted extensive research and studies on countermeasures.
その結果、焼入焼戻による寸法変化の原因が従来の認
識とは異なることを究明した。また、従来は、焼入焼戻
による寸法変化を正確に推定し、それを的確に圧延・切
断作業へ反映させる方法が採用されていないため、非焼
入焼戻材に比べて寸法に係る品質及び歩留、切断作業性
が劣っていたためであることも判明した。As a result, it was clarified that the cause of the dimensional change due to quenching and tempering is different from the conventional recognition. In addition, conventionally, the method of accurately estimating the dimensional change due to quenching and tempering and accurately reflecting it in the rolling and cutting work has not been adopted. It was also found that this was due to poor yield and cutting workability.
そこで、その対策について更に鋭意研究を重ねたとこ
ろ、焼入焼戻による寸法変化に及ぼす因子の影響を定量
化し、正確にこの変化量を把握すると共に、圧延及び焼
入前切断作業に反映させる寸法制御方法を開発するに至
ったものである。Therefore, after further intensive research on its countermeasures, the influence of factors on the dimensional change due to quenching and tempering was quantified, and the amount of this change was accurately grasped and the dimensions to be reflected in the cutting work before rolling and quenching. This led to the development of a control method.
すなわち、本発明に係る焼入焼戻を実施する厚鋼板の
寸法制御法は、炭素鋼及び合金鋼の厚鋼板を圧延し、切
断した後、Ac3以上に加熱してローラクエンチタイプの
装置で焼入し、次いでAc1以下で焼戻する方法におい
て、前記圧延及び切断に際し、化学成分による関数から
なる次式、 幅・長さ変化率ε＝α（1.0C＋0.0215Ni）（％） （但し、α：定数） に基づいて寸法変化を予測しつつ実施することを特徴と
するものである。That is, the dimension control method of the thick steel plate for carrying out quenching and tempering according to the present invention is a method of rolling a thick steel plate of carbon steel and alloy steel, cutting, and heating to Ac 3 or more in a roller quench type device. In the method of quenching and then tempering at Ac 1 or less, the following equation, which is a function of chemical components, is used for rolling and cutting, and the rate of change in width and length ε = α (1.0C + 0.0215Ni) (%) (however, , Α: constant) It is characterized in that it is carried out while predicting the dimensional change based on.
以下に本発明を更に詳細に説明する。 The present invention will be described in more detail below.
（作用） まず、焼入焼戻にする寸法変化の原因と影響因子の調
査結果について述べる。(Function) First, the cause of the dimensional change in quenching and tempering and the investigation result of the influencing factors will be described.
第１表は調査に供した厚鋼板の板厚と化学成分を示し
たものであり、板厚９〜90mm、Ｃ量0.04〜0.30％の炭素
鋼及び合金鋼（９％Ni鋼を含む）である。第１図は、こ
れらの厚鋼板を第１表に示す温度で焼入し、その前後の
幅・長さを測定し、化学成分fc（＝1.0C＋0.0215Ni）
（％）と幅・長さ増加率の関係を整理したものである。
なお、一部のものは２回焼入や焼入時の加熱温度を変化
させた。Table 1 shows the plate thickness and chemical composition of the thick steel plates used in the investigation. It is a carbon steel and alloy steel (including 9% Ni steel) with a plate thickness of 9 to 90 mm and a C content of 0.04 to 0.30%. is there. Fig. 1 shows that these thick steel plates were quenched at the temperatures shown in Table 1, the width and length before and after that were measured, and the chemical composition fc (= 1.0C + 0.0215Ni)
The relationship between (%) and the rate of increase in width and length is summarized.
It should be noted that some of the materials were quenched twice or the heating temperature during quenching was changed.
第１図から明らかなように、幅・長さは化学成分によ
って極めて大きな変化量を示し、化学成分fcと幅・長さ
増加率（変化率）には正比例の関係が成り立っている。
この関係は、幅・長さ変化率をεとすると、次式 ε＝α（1.0C＋0.0125Ni）（％） ……（１） （α：定数） にて表わすことができる。また一般の焼入温度による焼
入の場合には精度の良い相関を呈している。また、２回
焼入（１回焼入後と２回焼入後の寸法変化）の場合でも
ほぼ同様の幅・長さ増加が認められる。一方、焼入時の
加熱温度を低くしたものはこの増加量が小さくなり、ほ
ぼ焼入の加熱時の膨張量と一致する。 As is clear from FIG. 1, the width / length shows an extremely large amount of change depending on the chemical component, and the chemical component fc and the width / length increase rate (change rate) have a direct proportional relationship.
This relationship can be expressed by the following equation ε = α (1.0C + 0.0125Ni) (%) (1) (α: constant), where ε is the rate of change in width and length. Further, in the case of quenching at a general quenching temperature, a highly accurate correlation is exhibited. Also, in the case of two-time quenching (change in dimensions after one-time quenching and after two-time quenching), almost the same increase in width and length is observed. On the other hand, in the case where the heating temperature at the time of quenching is lowered, this increase amount becomes small, which is almost the same as the expansion amount at the time of heating during quenching.
したがって、焼入焼戻による寸法変化の原因は、従来
から認識されていたようなショットブラストや２回加熱
による板厚減少、マルテンサイト変態膨張による幅・長
さ増加に起因するのではなく、焼入前に膨張した鋼板
が、焼入初期において、そのままの幅・長さで表層部が
急冷されて剛性の強いものとなり、焼入末期において内
部が冷却しながら板厚方向に縮むためであることが判明
した。また、この変化量は、焼入の加熱において、膨張
率がα（フェライト）＜γ（オーステナイト）であるこ
とから、Ac変態点を低くするＣやNiを多量に含有するも
のの方が大きく、並びに加熱温度が高いほど大きくなる
ことも判明した。Therefore, the cause of the dimensional change due to quenching and tempering is not due to the conventionally recognized shot blasting, reduction in sheet thickness due to double heating, and increase in width and length due to martensite transformation expansion, but rather quenching. This is because the steel sheet that has expanded before quenching has its surface layer portion rapidly cooled with the same width and length at the beginning of quenching and becomes strong in rigidity, and at the end of quenching the interior shrinks in the sheet thickness direction while cooling. There was found. In addition, since the expansion coefficient α (ferrite) <γ (austenite) during heating during quenching, the amount of this change is larger for those containing a large amount of C or Ni that lowers the Ac transformation point, and It was also found that the higher the heating temperature, the higher the temperature.
一方、板厚変化率Δｔは、上記方法で得られた幅・長
さ変化率εから次式により単純計算にて求められる。On the other hand, the plate thickness change rate Δt can be obtained by a simple calculation by the following equation from the width / length change rate ε obtained by the above method.
以上の結果から、焼入焼戻に係る寸法変化は上記の如
く化学成分による関数にて予測可能である。したがっ
て、本発明は、これらの変化率を用いて圧延時の寸法補
正を実施すると共に、焼入前に、この幅・長さ変化を補
正して一挙に製品切断するものである。 From the above results, the dimensional change associated with quenching and tempering can be predicted by the function of the chemical composition as described above. Therefore, according to the present invention, the dimensional correction at the time of rolling is carried out by using these change rates, and the change in width and length is corrected before quenching, and the product is cut at once.
なお、本発明において、焼入焼戻を実施する対象鋼種
並びに焼入焼戻条件を規定したのは、焼入焼戻を実施す
る厚鋼板として利用され得る炭素鋼及び合金鋼の鋼種全
般を対象とするためであり、またその焼入焼戻条件もそ
れらに適用される条件とする必要があるためである。In the present invention, the target steel types for quenching and tempering and the quenching and tempering conditions are defined for all types of carbon steel and alloy steels that can be used as thick steel plates for quenching and tempering. This is because the quenching and tempering conditions must be the conditions applied to them.
次に本発明の実施例を示す。 Next, examples of the present invention will be described.
（実施例） 第１表に示す化学成分を有する供試鋼について、圧延
後、切断し、焼入焼戻を施して、板厚６〜50mm、幅1000
〜4200mm、長さ6096〜18500mmの焼入焼戻厚板鋼板を製
造した。(Example) With respect to the sample steel having the chemical composition shown in Table 1, after rolling, cutting, quenching and tempering were performed to obtain a plate thickness of 6 to 50 mm and a width of 1000.
Hardened and tempered thick steel plates with a length of ~ 4200 mm and a length of 6096-18500 mm were manufactured.
なお、焼入は、HT50〜80鋼及び耐摩耗鋼については93
0℃に、3.5％Ni鋼については850℃に、また９％Ni鋼に
ついては800℃にそれぞれ加熱後、ローラクエンチ装置
で水冷した。焼戻は、HT50〜80鋼及び3.5％Ni鋼につい
ては620〜670℃に、耐摩耗鋼については300〜550℃に、
９％Ni鋼については580℃にそれぞれ加熱後、空冷し
た。Note that quenching is 93 for HT50-80 steel and wear-resistant steel.
After heating to 0 ° C., 3.5% Ni steel to 850 ° C., and 9% Ni steel to 800 ° C., they were water-cooled by a roller quench apparatus. Tempering is 620-670 ℃ for HT50-80 steel and 3.5% Ni steel, 300-550 ℃ for wear resistant steel,
The 9% Ni steel was heated to 580 ° C and air-cooled.
また、圧延及び切断に際しては、本発明法の場合に
は、前記式（１）及び（２）に基づいて圧延仕上り寸
法、切断寸法を補正して実施した。比較法の場合にはか
ゝる補正を実施しなかった。Further, in the rolling and cutting, in the case of the method of the present invention, the rolling finish dimension and the cutting dimension were corrected based on the formulas (1) and (2). No such correction was made for the comparative method.
得られた厚板鋼板の板厚精度について、比較法による
結果（ｎ＝87）を第２図に、本発明法による結果（ｎ＝
84）を第３図にそれぞれ示し、また鋼板の幅精度につい
て、比較法による結果（ｎ＝87）を第４図に、本発明法
による結果（ｎ＝84）を第５図にそれぞれ示す。Regarding the plate thickness accuracy of the obtained thick steel plate, the result by the comparison method (n = 87) is shown in FIG. 2, and the result by the method of the present invention (n = 87)
84) is shown in FIG. 3, the result of the comparative method (n = 87) is shown in FIG. 4, and the result of the method of the present invention (n = 84) is shown in FIG.
第２図〜第３図から明らかなように、本発明法による
板厚精度は、比較法に比べ、（実厚−目標下限厚）のバ
ラツキσが0.24mmから0.18mmに改善されている。また、
第４図〜第５図から明らかなように、本発明法によれば
幅マージンのバラツキσが4.5mmから2.5mmに改善されて
いる。As is clear from FIGS. 2 to 3, in the plate thickness accuracy according to the method of the present invention, the variation σ of (actual thickness-target lower limit thickness) is improved from 0.24 mm to 0.18 mm as compared with the comparative method. Also,
As is clear from FIGS. 4 to 5, according to the method of the present invention, the variation σ of the width margin is improved from 4.5 mm to 2.5 mm.
（発明の効果） 以上詳述したように、本発明によれば、焼入焼戻によ
る寸法変化を圧延及び焼入前切断の寸法に反映させ、し
かもその場合に化学成分による特定の関数に基づいて寸
法制御するので、非焼入焼戻材の寸法精度に近いものに
改善され、構造物の重量精度に対する需要化の厳格板厚
仕様を容易に満足させると共に計算重量の精度を高める
ことができる。(Effects of the Invention) As described in detail above, according to the present invention, the dimensional changes due to quenching and tempering are reflected in the dimensions of rolling and cutting before quenching, and in that case, based on a specific function depending on the chemical composition. Since the dimensional control is performed by the dimensional control, the dimensional accuracy can be improved to be close to that of the non-quenched and tempered material, and it is possible to easily satisfy the strict plate thickness specification of the demand for the weight accuracy of the structure and increase the accuracy of the calculated weight. .
また、従来法の焼入前仮切断、焼入後最終切断に対し
て、焼入前の切断のみでASTMA6のガス切材の幅公差値
（板厚≦50.8mmの場合のマージン:0〜12.7mm）をも満足
するものが得られるようになり、切断作業性を改善する
ことができる。In addition, in contrast to the conventional method of temporary cutting before quenching and final cutting after quenching, the width tolerance value of the gas cutting material of ASTM A6 (margin in the case of plate thickness ≤ 50.8 mm: 0 to 12.7 mm) can be obtained and the cutting workability can be improved.
また、板厚・幅・長さの精度の向上により、これを圧
延寸法に反映することにより、従来よりも素材を小さく
して歩留を1.0〜1.5％向上させることができる。Further, by improving the accuracy of the plate thickness / width / length and reflecting this in the rolling dimension, the material can be made smaller and the yield can be improved by 1.0 to 1.5% as compared with the conventional one.
【図面の簡単な説明】 第１図は化学成分fcと焼入による幅・長さ増加率εの相
関を示す図であり、第２図は比較法で得られた板厚のヒ
ストグラムであり、第３図は本発明法で得られた板厚の
ヒストグラムであり、第４図は比較法で得られた幅マー
ジンのヒストグラムであり、第５図は本発明法で得られ
た幅マージンのヒストグラムである。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a correlation between a chemical component fc and a width / length increase rate ε due to quenching, and FIG. 2 is a sheet thickness histogram obtained by a comparative method. FIG. 3 is a histogram of the plate thickness obtained by the method of the present invention, FIG. 4 is a histogram of the width margin obtained by the comparison method, and FIG. 5 is a histogram of the width margin obtained by the method of the present invention. Is.
Claims (1)
した後、Ac3以上に加熱してローラクエンチタイプの装
置で焼入し、次いでAc1以下で焼戻する方法において、
前記圧延及び切断に際し、化学成分による関数からなる
次式、 幅・長さ変化率ε＝α（1.0C＋0.0215Ni）（％） （但し、α：定数） に基づいて寸法変化を予測しつつ実施することを特徴と
する焼入焼戻を実施する厚鋼板の寸法制御法。1. A method of rolling a thick steel plate of carbon steel and alloy steel, cutting it, heating it to Ac 3 or more, quenching it with a roller quench type device, and then tempering it with Ac 1 or less,
When rolling and cutting, the following equation consisting of a function depending on the chemical composition, width / length change rate ε = α (1.0C + 0.0215Ni) (%) (where α: constant) A method for controlling the dimension of a thick steel plate for performing quenching and tempering, which is performed while predicting a dimensional change based on the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1037082A JP2546889B2 (en) | 1989-02-16 | 1989-02-16 | Dimension control method of thick steel plate for quenching and tempering |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1037082A JP2546889B2 (en) | 1989-02-16 | 1989-02-16 | Dimension control method of thick steel plate for quenching and tempering |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02217103A JPH02217103A (en) | 1990-08-29 |
| JP2546889B2 true JP2546889B2 (en) | 1996-10-23 |
Family
ID=12487629
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1037082A Expired - Lifetime JP2546889B2 (en) | 1989-02-16 | 1989-02-16 | Dimension control method of thick steel plate for quenching and tempering |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2546889B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6819469B2 (en) * | 2017-06-06 | 2021-01-27 | 日本製鉄株式会社 | Manufacturing method of heat-treated steel sheet |
-
1989
- 1989-02-16 JP JP1037082A patent/JP2546889B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02217103A (en) | 1990-08-29 |
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