JPH0432514A - Production of soft wire rod free from surface abnormal phase in as-rolled state - Google Patents
Production of soft wire rod free from surface abnormal phase in as-rolled stateInfo
- Publication number
- JPH0432514A JPH0432514A JP14029090A JP14029090A JPH0432514A JP H0432514 A JPH0432514 A JP H0432514A JP 14029090 A JP14029090 A JP 14029090A JP 14029090 A JP14029090 A JP 14029090A JP H0432514 A JPH0432514 A JP H0432514A
- Authority
- JP
- Japan
- Prior art keywords
- rolling
- wire rod
- less
- steel
- rolled
- 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
- 230000002159 abnormal effect Effects 0.000 title claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- 238000005096 rolling process Methods 0.000 claims abstract description 58
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 29
- 239000010959 steel Substances 0.000 claims abstract description 29
- 238000001816 cooling Methods 0.000 claims abstract description 22
- 238000010438 heat treatment Methods 0.000 claims abstract description 9
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 4
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 4
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 3
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 3
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 3
- 239000000463 material Substances 0.000 claims description 23
- 238000005098 hot rolling Methods 0.000 claims description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 239000012535 impurity Substances 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 238000005482 strain hardening Methods 0.000 abstract description 5
- 239000000203 mixture Substances 0.000 abstract description 4
- 238000010273 cold forging Methods 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 abstract 2
- 229910052799 carbon Inorganic materials 0.000 abstract 1
- 229910052804 chromium Inorganic materials 0.000 abstract 1
- 238000003754 machining Methods 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 21
- 238000000034 method Methods 0.000 description 20
- 238000000137 annealing Methods 0.000 description 13
- 229910001566 austenite Inorganic materials 0.000 description 12
- 239000012467 final product Substances 0.000 description 8
- 238000001953 recrystallisation Methods 0.000 description 8
- 229920006395 saturated elastomer Polymers 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 238000004804 winding Methods 0.000 description 6
- 229910001563 bainite Inorganic materials 0.000 description 5
- 230000006866 deterioration Effects 0.000 description 4
- 229910001562 pearlite Inorganic materials 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 238000010583 slow cooling Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 229910000734 martensite Inorganic materials 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 239000002344 surface layer Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229920000742 Cotton Polymers 0.000 description 1
- 229910003294 NiMo Inorganic materials 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 238000009749 continuous casting Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005242 forging Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
［ａ業上の利用分野］
本発明は圧延ままで表面異常相のない軟質線材の製造方
法にかかわり、さらに詳しくは、自動車用部品、建設機
械用部品等の製造に際して、圧延ままで表面異常相かな
く且つ軟化焼鈍を省略して引き抜ぎ、切削、論量鍛造等
の冷間加工を容易に行うことができる軟質線材の製造方
ン去に関するもので・ある。[Detailed Description of the Invention] [Field of Application in Industry A] The present invention relates to a method for manufacturing a soft wire rod as rolled and free of surface abnormal phases, and more specifically, for manufacturing automobile parts, construction machinery parts, etc. This invention relates to a method for producing a soft wire rod that does not have any surface abnormalities as rolled and can be easily subjected to cold working such as drawing, cutting, and stoichiometric forging by omitting softening annealing.
［従来の技術］
従来、自動車用部品、建設機械用部品等は、引き抜き、
切削、冷間鍛造等の冷間加工の前に冷間加工性の向上を
目的として、軟化焼鈍が行われている。これらの焼鈍は
通常数時間を要し、焼鈍処理のコストは近年のエネルギ
高騰とともにこれらの機械部品の製造コストのなかで大
きなウェイトを占めようになってきている。[Conventional technology] Conventionally, parts for automobiles, parts for construction machinery, etc. were extracted,
Before cold working such as cutting and cold forging, softening annealing is performed for the purpose of improving cold workability. These annealing processes usually take several hours, and the cost of the annealing process has come to account for a large portion of the manufacturing cost of these mechanical parts as energy prices have skyrocketed in recent years.
このために、さらにまた生産性の向上の観点から冷間加
工の荊の軟化焼鈍省略の指向は強い。For this reason, and from the viewpoint of improving productivity, there is a strong tendency to omit the softening annealing of cold working.
これに対して、特公昭５９−３１５７３号公報には、熱
間圧延後７００〜８５０℃まで急冷、その後７００〜７
７５℃まて保持もしくは５℃／秒以下て冷却、その後６
００〜６７５℃を０．０２５〜０．２５℃／秒て冷却す
る熱間圧延線材の直接熱処理方法か示されている。On the other hand, Japanese Patent Publication No. 59-31573 discloses that after hot rolling, the temperature is rapidly cooled to 700 to 850°C, and then to 700 to 700°C.
Hold at 75℃ or cool at 5℃/second or less, then 6
A direct heat treatment method for hot rolled wire rods is shown in which the temperature is 0.025 to 0.25°C per second.
また、特公平１−１２８１５号公報には、特定組成から
なる鋼をＡｃ３変態点以上に加熱して熱間圧延し、ＡＣ
３変態点〜ＡＣ３変態点＋２００℃で総減面率４０％以
上の仕上げ圧延を行った後、冷却速度００５〜ｂ
優れた低合金鋼の製造方法か示されている。In addition, Japanese Patent Publication No. 1-12815 discloses that steel having a specific composition is heated to the Ac3 transformation point or higher and hot rolled,
After finish rolling with a total area reduction of 40% or more at 3 transformation point to AC3 transformation point + 200° C., a cooling rate of 005 to b is shown.An excellent method for manufacturing low alloy steel is shown.
［発明か解決しようとする課題］
しかし、前記特公昭５９−３１５７３号公報の方法では
圧延後の冷却に時間を要して生産性が悪く、また上限近
くの冷却速度を選択すると軟化焼鈍レベルまて十分に軟
化しない等の欠点かある。[Problem to be solved by the invention] However, the method disclosed in Japanese Patent Publication No. 59-31573 has poor productivity because it takes time to cool down after rolling, and if a cooling rate close to the upper limit is selected, the method does not reach the softening annealing level. There are drawbacks such as not softening sufficiently.
また、特公平１−１２８１５号公報による方法では、圧
延仕上げ直後のオーステナイト結晶粒度を６番以上とし
、熱間圧延ままて微細なフェライト・パーライト組織を
得ることを狙いとしている。しかしながら、この方法で
得られる熱間圧延ままでの線材は、冷間加工性は従来の
軟化焼鈍に比べて不十分であり、さらに、表面にフェラ
イ）・分率が９０％以上である異常相（以下、表面異常
相と呼ぶ）か現出する。Furthermore, the method disclosed in Japanese Patent Publication No. 1-12815 aims to make the austenite crystal grain size 6 or more immediately after rolling finish, and to obtain a fine ferrite-pearlite structure as hot-rolled. However, the as-hot-rolled wire rod obtained by this method has insufficient cold workability compared to conventional softening annealing, and furthermore, the wire rod has an abnormal phase with a ferrite fraction of 90% or more on the surface. (hereinafter referred to as surface abnormal phase) appears.
以上のように圧延ままでの軟質線材は実用化に至ってい
ないのか現状である。As mentioned above, the current situation is that as-rolled soft wire rods have not yet been put into practical use.
本発明の目的は、熱間圧延ままて従来の軟化焼鈍レベル
の優れた冷間加工性を保証し、且つ表面異常相か存在し
ない軟質線材の製造方法を提供しようとするものである
。An object of the present invention is to provide a method for producing a soft wire rod that guarantees excellent cold workability of the as-hot-rolled wire rod at the level of conventional softening annealing, and that has no abnormal surface phase.
［課題を解決するための手段、作用］
本発明者らは、熱間圧延ままで従来の軟化焼鈍レベルの
優れた冷間加工性を保証し、且つ表面異常相か存在しな
い軟質線材を実現するために、鋭意検討を行ない次の知
見を得た。[Means and effects for solving the problem] The present inventors have achieved a soft wire rod that guarantees excellent cold workability at the level of conventional softening annealing even after hot rolling, and has no surface abnormal phase. In order to achieve this goal, we conducted extensive research and obtained the following knowledge.
（１）従来の軟化焼鈍材と同等レベルの冷間加工性を熱
間圧延ままて得るためには、圧延仕上げ直後のオーステ
ナイト結晶粒度を８番以上として、熱間圧延ままてベイ
ナイト分率が５％以下で且つ微細なフェライト・パーラ
イト組織を得なけれはならない。(1) In order to obtain the same level of cold workability as the conventional softened annealed material in the as-hot rolled material, the austenite grain size immediately after rolling finish should be set to 8 or more, and the bainite fraction in the as-hot rolled material should be 5. % or less and a fine ferrite-pearlite structure must be obtained.
（２）圧延仕上げ直後のオーステナイト結晶粒度を８番
以上とするためには、次の３点が必須である。(2) In order to make the austenite grain size No. 8 or higher immediately after rolling finishing, the following three points are essential.
■ 特定量の日、Ｎ等の炭窒化物生成元素を含有する鋼
材を用い、圧延加熱温度を９００〜１２５０℃に限定し
て、圧延加熱時のオーステナイト粒の粗大化を防止する
こと。(2) Use a steel material containing a specific amount of carbonitride-forming elements such as N, and limit the rolling heating temperature to 900 to 1250°C to prevent coarsening of austenite grains during rolling heating.
■ ８８０℃以上の温度範囲で総減面率５０％以上の圧
延を行い、再結晶によりオーステナイト粒を６〜７番程
度に細粒化すること。(2) Rolling is performed at a temperature range of 880° C. or higher with a total area reduction of 50% or more, and the austenite grains are refined to about No. 6 to 7 by recrystallization.
■ ８８０℃未満の温度範囲で、「減面率１０％以上の
圧延後、直ちに鋼材表面温度が一旦Ｍｓ点〜７００℃と
なるように冷却し、引き続いて減面率１０％以上の圧延
を行う」工程を１回以上有する工程で圧延を行うことに
より、各バスでの歪を累積し、累積大荒による再結晶細
粒化を促進し、さらに最終圧延出側の鋼材表面温度を７
５０〜８８０℃とすることにより、オーステナイト粒の
成長粗大化を抑制すること。■ In a temperature range of less than 880℃, after rolling with an area reduction of 10% or more, immediately cool the steel surface temperature to the Ms point to 700℃, and then continue rolling with an area reduction of 10% or more. By performing rolling in a process that has one or more steps, the strain in each bath is accumulated, recrystallization becomes finer due to the cumulative roughness, and the surface temperature of the steel material on the exit side of the final rolling is lowered to 7.
By controlling the temperature to 50 to 880°C, growth and coarsening of austenite grains can be suppressed.
（３）さらに、ベイナイト分率を５％以下に抑えて良好
な冷間加工性を有するためには、捲取り後コイル状で、
７００〜５５０℃を平均冷却速度で０．０５〜ｂ
である。(3) Furthermore, in order to suppress the bainite fraction to 5% or less and have good cold workability, it is necessary to
The average cooling rate from 700 to 550°C is 0.05 to b.
（４）また、表面異常相は什上げ圧延−捲取り間の脱炭
かその主たる原因であり、什上げ圧延後綿材の表面温度
か７００〜８００℃となるように急冷した後捲取ること
により、表面異常相の発生は防止できる。(4) Also, the main cause of the abnormal phase on the surface is decarburization between the top rolling and winding, and after the top rolling, the cotton material should be rapidly cooled to a surface temperature of 700 to 800°C before winding. As a result, the occurrence of surface abnormal phases can be prevented.
本発明は以上の新規なる知見にもとづいてなされたもの
であって、その要旨とするところは、
重量比として、
Ｃ：０．１０〜０５０％、
Ｓｉ：０．０１〜０．４０％、
Ｍｎ：０．２５〜１．７０％、
Ｓ：０．０１〜０．１５％、
人文：０．０１５〜０．０５％、
Ｎ：０．００３〜０．０２０％、
を含有し、
Ｐ：０．０３５％以下に制限し、
さらにまたは、
Ｃｒ：１．５％以下、
Ｎｉ：３．５％以下、
Ｍｏ：１．０％以下、
Ｂ・０．００５％以下
の１種または２種以上を含有し、
さらにまたは、
Ｔｉ：０．００５〜０．０４％、
Ｎｂ：０．００５〜０１％、
Ｖ００３〜０．３％
の１種または２種以上を含有し、残部か鉄および不可避
的不純物からなる鋼を熱間圧延するに際して、
（Ａ） ９００〜１２５０℃に加熱する工程と、（Ｂ
） ８８０℃以上の温度範囲で総減面率５０％以上の
圧延を行う工程と、
（Ｃ）その後、８８０℃未満の温度範囲で、「減面率１
０％以上の圧延後、直ちに鋼材表面温度が一旦Ｍｓ点〜
７００℃となるように冷却し、弓き続いて減面率１０％
以上の圧延を行う」工程を１回以上有する工程で圧延を
行い、最終圧延出側の鋼材表面温度を７５０〜８８０ｔ
とする工程と、
（Ｄ）仕上げ圧延後、該線材の表面温度か７００〜８０
０℃となるように急冷した後捲取る工程と、
（Ｅ）その後コイル状で ７００〜５００℃の温度範囲
を平均冷却速度で０．０５〜ｂ
る工程とを有してなることを特徴とする圧延ままて表面
異常相のない軟質線材の製造方法にある。The present invention has been made based on the above-mentioned new findings, and its gist is as follows: As a weight ratio, C: 0.10-050%, Si: 0.01-0.40%, Mn. Contains: 0.25-1.70%, S: 0.01-0.15%, Humanities: 0.015-0.05%, N: 0.003-0.020%, P: 0 .035% or less, and one or more of the following: Cr: 1.5% or less, Ni: 3.5% or less, Mo: 1.0% or less, B.0.005% or less Contains, and further contains one or more of Ti: 0.005~0.04%, Nb: 0.005~01%, V003~0.3%, and the balance is iron and inevitable impurities. When hot rolling steel made of
) A step of rolling with a total area reduction of 50% or more in a temperature range of 880°C or higher; (C) Thereafter, rolling with a total area reduction of 1
Immediately after rolling 0% or more, the steel surface temperature once reaches the Ms point.
Cool to 700℃, continue to bow, and reduce area by 10%
Rolling is performed in a process that has one or more steps of ``rolling as described above'', and the surface temperature of the steel material on the exit side of the final rolling is maintained at 750 to 880 t.
(D) After finish rolling, the surface temperature of the wire is 700 to 80.
It is characterized by comprising a step of rapidly cooling it to 0°C and then rolling it up, and (E) a step of thereafter coiling it in a temperature range of 700 to 500°C at an average cooling rate of 0.05 to b. The present invention provides a method for producing a soft wire rod without surface abnormal phases while still being rolled.
以下に、本発明の詳細な説明する。The present invention will be explained in detail below.
ます、Ｃは機械部品としての最終製品の強度を増加させ
るのに有効な元素であるか、０１０％未満では最終製品
の強度が不足し、また０、５０％を越えるとむしろ最終
製品の靭性の劣化を招くので、含有量を０，１０〜０．
５０％とした。Is C an effective element for increasing the strength of the final product as a mechanical part? If it is less than 0.10%, the strength of the final product will be insufficient, and if it exceeds 0.50%, it will actually reduce the toughness of the final product. Since this may cause deterioration, the content should be reduced to 0.10-0.
It was set at 50%.
次に、Ｓｌは脱酸元素としておよび固溶体硬化による最
終製品の強度を増加させることを目的として添加するが
、０．０１％未満てはこれらの効果は不十分であり、一
方、 ０．４％を超えるとこれらの効果は飽和しむしろ
最終製品の靭性の劣化を招くので、その含有量を０．０
１〜０．４％とした。Next, Sl is added as a deoxidizing element and for the purpose of increasing the strength of the final product by solid solution hardening, but if it is less than 0.01%, these effects are insufficient; on the other hand, if it is less than 0.4% If the content exceeds 0.0, these effects will become saturated and the toughness of the final product will deteriorate.
The content was set at 1% to 0.4%.
Ｍｎは焼入れ性の向上を通じて、最終製品の強度を増加
させるのに有効な元素であるが、０．２５％未満ではこ
の効果は不十分であり、方、 １７％を超えるとこの効
果は飽和しむしろ最終製品の靭性の劣化を招くので、そ
の含有量を０２５％〜１．７％とした。Mn is an effective element for increasing the strength of the final product by improving hardenability, but if it is less than 0.25%, this effect is insufficient, and if it exceeds 17%, this effect is saturated. Rather, it causes deterioration of the toughness of the final product, so its content was set at 0.25% to 1.7%.
また、Ｓは鋼中てＭｎＳとして存在し、被剛性の向上お
よび組織の微細化に寄与するか、０．０１％未満ではそ
の効果は不十分である。一方、０．１５％を超えるとそ
の効果は飽和し、むしろ靭性の劣化及び異方性の増加を
招く。以上の理由から、Ｓの含有量を００１〜０．１５
％とした。Further, S exists in the form of MnS in steel, and contributes to improving rigidity and refining the structure, but if it is less than 0.01%, the effect is insufficient. On the other hand, if it exceeds 0.15%, the effect will be saturated, rather leading to deterioration in toughness and increase in anisotropy. For the above reasons, the S content was set to 0.01 to 0.15.
%.
次に、Ａｎは脱酸元素および結晶粒微細化元素として添
加するか、 ０．０１５％未満ではその効果は不十分で
あり、一方、０．０５％を超えるとその効果は飽和し、
むしろ靭性を劣化させるので、その含有量を０．０１５
〜００５％とした。Next, An should be added as a deoxidizing element and a grain refining element; if it is less than 0.015%, the effect is insufficient; on the other hand, if it exceeds 0.05%, the effect is saturated;
Rather, it deteriorates the toughness, so the content should be reduced to 0.015
~005%.
さらに、ＮはＡρＮの析出挙動を通じて、オーステナイ
ト粒／フェライト・パーライト組織の微細化に寄与する
か、 ０．００３％未満ではその効果は不十分であり、
一方、 ０．０２０％超では、その効果は飽和しむしろ
靭性の劣化を招くので、その含有量をＮ： ０．００３
〜０．０２０％とした。Furthermore, N contributes to the refinement of the austenite grain/ferrite/pearlite structure through the precipitation behavior of AρN, or the effect is insufficient if it is less than 0.003%.
On the other hand, if it exceeds 0.020%, the effect will be saturated and the toughness will deteriorate, so the content should be reduced to N: 0.003%.
~0.020%.
一方、Ｐは鋼中で粒界偏析や中心偏析を起こし、靭性劣
化の原因となる。特にＰが０．０３５％を超えると靭性
の劣化か顕著となるため、０．０３５％を上限とした。On the other hand, P causes grain boundary segregation and center segregation in steel, causing toughness deterioration. In particular, when P exceeds 0.035%, the toughness deteriorates significantly, so 0.035% is set as the upper limit.
次に本発明で用いる鋼においては、Ｃｒ、 ＮｉＭｏ
Ｂの１種又は２種以上を含有させることができる。こ
れらの元素は焼入れ性の増加により最終製品の強度を増
加させるために添加する。Next, in the steel used in the present invention, Cr, NiMo
One or more types of B can be contained. These elements are added to increase the strength of the final product by increasing its hardenability.
ただしこれらの元素の多量添加は熱間圧延ままでベイナ
イト、マルテンサイト組織を生じて硬さの増加を招き、
また経済性の点て好ましくないためその含有量を、
Ｃｒ：１．５％以下、
Ｎｉ ： ３．５％以下、
Ｍｏ：１．０％以下、
Ｂ ＋０．００５％以下
とした。However, addition of large amounts of these elements causes bainite and martensitic structures during hot rolling, leading to increased hardness.
Moreover, since it is not preferable from an economic point of view, the contents are set to Cr: 1.5% or less, Ni: 3.5% or less, Mo: 1.0% or less, and B +0.005% or less.
さらに本発明においては、粒度調整の目的で、Ｔｉ、
Ｎｂ、 Ｖ （７） １ ｆｍ又は２種以上を必須元素
として含有させることができる。しかしながら、Ｔユ含
有量が０．００５％未満、Ｎｂ含有量か０．００５％未
満、Ｖ含有量が０．０３％未満ではその効果は不十分て
あり、一方、Ｔｉ ： ０．０４０％超、Ｎｂ ：
０．１０％超、Ｖ：０．３０％超では、ソノ効果は飽和
し、むしろ靭性を劣化させるのて、これらの含有量を７
ｉ 、 ０．００５〜０．０４０％、 Ｎｂ： ０
．００５〜０．１％ ■００３〜０．３％とした。Furthermore, in the present invention, for the purpose of particle size adjustment, Ti,
Nb, V (7) 1 fm or two or more types can be contained as essential elements. However, the effect is insufficient when the T content is less than 0.005%, the Nb content is less than 0.005%, and the V content is less than 0.03%; on the other hand, Ti: more than 0.040%. , Nb:
When the content exceeds 0.10% and V: 0.30%, the sono effect is saturated and the toughness is rather deteriorated.
i, 0.005-0.040%, Nb: 0
．． 005-0.1% ■003-0.3%.
次に、本発明において、熱間圧延条件を限定した理由に
ついて述べる。Next, the reason for limiting the hot rolling conditions in the present invention will be described.
まず、加熱温度を９００〜１２５０℃としたのは、９０
０℃未満の加熱温度では粗圧延−中間圧延温度が低くな
り再結晶域圧延によるオーステナイト粒の細粒化か不十
分であるためであり、また１２５０℃以上の加熱温度で
はオーステナイト結晶粒か顕著に粗大化するためである
。First, the heating temperature was set at 900 to 1250°C.
This is because at a heating temperature of less than 0°C, the rough rolling-intermediate rolling temperature becomes low and the austenite grains are insufficiently refined by recrystallization zone rolling, and at a heating temperature of 1250°C or higher, the austenite crystal grains become noticeably smaller. This is because it becomes coarser.
次に、８８０℃以上の温度範囲で総減面率５０％以上の
圧延を行うのは、再結晶によりオーステナイト粒を６〜
７番程度に細粒化するためてあり、総減面率５０％以上
としたのは、これ未満ては再結晶細粒化の効果が小さい
ためである。Next, rolling with a total area reduction of 50% or more in a temperature range of 880°C or higher is necessary to reduce the austenite grains by recrystallization.
The reason why the total area reduction rate is set to be 50% or more is because the effect of recrystallization to refine grains is small below this.
また、８８０℃未満の温度範囲で、「減面率１０％以上
の圧延後、直ちに鋼材表面温度か一旦Ｍｓ点〜７００℃
となるように冷却し、引き続いて減面率を１０％以上の
圧延を行う」工程を１回以上有する工程で圧延を行い、
最終圧延出側の鋼材表面温度を７００〜８８０℃とする
のは、以下の理由による。８８０℃未満の温度範囲にお
ける圧延では、通常、再結晶か困難て、主として回復に
より加工歪の解放か起こるため、オーステナイト粒の細
粒化は困難である。これに対して、圧延後直ちに冷却し
て回復による加工歪の解放を抑制して歪を累積させ、実
質的に大きな歪を残存させれば、再結晶細粒化が可能で
ある。この現象は、「減面率１０％以上の圧延後、直ち
に鋼材表面温度か一旦Ｍｓ点〜７００℃となるように冷
却し、引き続いて減面率１０％以上の圧延を行う」工程
を１回以上有する工程で圧延を行うことによって実現可
能である。ここで、冷却前後の減面率１０％以上とした
のは、減面率１０％未満では累積される歪量が小さいた
め再結晶細粒化に対する効果が不十分なためである。ま
た、冷却後の表面温度をＭｓ点〜７００℃としたのは、
冷却後の表面温度が７００℃を超えると加工歪の解放の
抑制が不十分であり、方Ｍｓ点未満であると表層にマル
テンサイト組織が生じるためである。なお、加工歪の解
放の抑制の効果は、 ６００℃未満に冷却することによ
って特に顕著になることから、可能ならば冷却後の表面
温度をＭｓ点点上上 ６００℃未満とするのが望ましい
。また、本発明では８８０℃未満の温度範囲において、
「減面率１０％以上の圧延後、直ちに鋼材表面温度か一
旦Ｍｓ点〜７００℃となるように冷却し、引き続いて減
面率１０％以上の圧延を行う」工程の前後に任意の圧延
を行うことが可能であり、またこの工程を２回以上繰り
返す場合、連続して行っても、任意の圧延をはさんで行
っても良い。次に、最終圧延出側の鋼材表面温度を７５
０〜８８０℃の範囲とするのは、７５０℃未満の仕上げ
温度では、仕上げ圧延前または仕上げ圧延中に鋼材表層
部分でフェライトが生成する危険性があり、また仕上げ
温度が８８０℃を超えた場合、圧延直後のオーステナイ
ト粒が成長粗大化する危険性があるためである。In addition, in a temperature range of less than 880℃, "After rolling with an area reduction rate of 10% or more, the surface temperature of the steel material is immediately raised to the Ms point to 700℃.
Rolling is performed in a process having one or more steps of "cooling the material so that
The reason why the surface temperature of the steel material on the exit side of the final rolling is set to 700 to 880°C is as follows. In rolling in a temperature range below 880° C., it is difficult to refine the austenite grains because recrystallization is usually difficult and release of working strain occurs mainly through recovery. On the other hand, if the steel is cooled immediately after rolling to suppress the release of processing strain due to recovery and accumulate strain, and substantially large strain remains, recrystallization becomes possible. This phenomenon can be solved by carrying out the process of ``immediately after rolling with an area reduction of 10% or more, the surface temperature of the steel material is once cooled to the Ms point ~ 700℃, and then rolling is performed with an area reduction of 10% or more.'' This can be achieved by rolling in the steps described above. Here, the reason why the area reduction ratio before and after cooling is set to be 10% or more is because if the area reduction ratio is less than 10%, the amount of accumulated strain is small and the effect on recrystallization grain refinement is insufficient. In addition, the reason why the surface temperature after cooling was set to Ms point ~ 700°C was because
This is because if the surface temperature after cooling exceeds 700° C., the release of processing strain is insufficiently suppressed, and if it is below the Ms point, a martensitic structure will occur in the surface layer. Note that the effect of suppressing the release of processing strain becomes particularly noticeable by cooling to less than 600°C, so if possible, it is desirable to set the surface temperature after cooling to less than 600°C above the Ms point. Furthermore, in the present invention, in a temperature range of less than 880°C,
``After rolling with an area reduction of 10% or more, immediately cool the steel material surface temperature to the Ms point ~ 700℃, and then continue rolling with an area reduction of 10% or more.'' Any rolling before or after the process. If this process is repeated two or more times, it may be performed continuously or with optional rolling in between. Next, the surface temperature of the steel material on the exit side of the final rolling was set to 75
The range of 0 to 880°C is because if the finishing temperature is less than 750°C, there is a risk that ferrite will be generated in the surface layer of the steel material before or during finish rolling, and if the finishing temperature exceeds 880°C. This is because there is a risk that the austenite grains will grow and coarsen immediately after rolling.
次に、仕上げ圧延後詰線材の表面温度が７００〜８００
℃となるように急冷した後捲取るのは、表面異常相の発
生を防止するためである。捲取り前の温度が８００℃を
超えると表面異常相発生防止の効果が不十分であり、ま
た捲取り前の温度が７００℃未満であると微細パーライ
トが生成して硬さが増加する危険性があるため、捲取り
温度範囲を７００〜８００℃とした。Next, the surface temperature of the stuffed wire rod after finish rolling is 700 to 800.
The reason why the film is rapidly cooled to ℃ and then rolled up is to prevent the formation of abnormal phases on the surface. If the temperature before winding exceeds 800°C, the effect of preventing surface abnormal phase formation will be insufficient, and if the temperature before winding is less than 700°C, there is a risk that fine pearlite will be generated and hardness will increase. Therefore, the winding temperature range was set to 700 to 800°C.
また捲取り後、コイル状で７００〜５５０℃の温度範囲
を平均冷却速度で０．０５〜０．７℃／秒で冷却するの
は、７００〜５５０℃の冷却速度が０．７℃／秒を超え
ると、圧延冷却後の組織が、ベイナイトか５％以上混在
する組織となるためであり、一方００５℃／秒未満ては
徐冷の効果か飽和し、いたずらに時間を消費するためで
ある。なお、５５０℃以下の冷却は任意の冷却速度を選
ぶことができる。また、調整冷却の方法として、コイル
搬送ラインに徐冷カバーをかける等適宜の方法かとられ
る。In addition, after winding, the coil is cooled at an average cooling rate of 0.05 to 0.7°C/sec in the temperature range of 700 to 550°C. This is because if the temperature exceeds 0.05°C/sec, the structure after rolling and cooling will be a structure containing 5% or more of bainite, while if it is below 0.05°C/sec, the slow cooling effect will be saturated and time will be wasted unnecessarily. . Note that an arbitrary cooling rate can be selected for cooling below 550°C. Further, as a method of controlled cooling, an appropriate method such as covering the coil conveyance line with a slow cooling cover may be used.
以下に、本発明の効果を実施例により、さらに具体的に
示す。Below, the effects of the present invention will be illustrated in more detail with reference to Examples.
［実 施 例］ 第１表に供試材の化学成分を示す。[Example] Table 1 shows the chemical composition of the sample materials.
これらはいずれも転炉溶製後連続鋳造で鋳造された。１
６２ｍｍ角鋼片に分塊圧延後、第２表に示す圧延条件で
１９ｍｍ径線材に圧延した。本発明法の圧延Ｎｏ、Ｉお
よび比較例の圧延Ｎｏ、Ｉｌについては、圧延後コイル
搬送ラインに徐冷カバーをかけることにより調整冷却を
行った。また、比較例の圧延Ｎ ｏ 、 Ｉｌｌで圧延
した材料についてのみ、 ６８０℃×２時間加熱放冷の
条件で軟化焼鈍を行った。All of these were cast by continuous casting after melting in a converter furnace. 1
After blooming into a 62 mm square steel billet, it was rolled into a 19 mm diameter wire rod under the rolling conditions shown in Table 2. Regarding rolling No. I of the present invention method and rolling No. Il of the comparative example, adjusted cooling was performed by placing a slow cooling cover on the coil conveyance line after rolling. In addition, only the materials rolled by the rolling method N o and Ill of the comparative example were subjected to softening annealing under the conditions of heating and cooling at 680° C. for 2 hours.
冷間加工性の指標として硬さの評価を行った。第３表に
各鋼材の材質特性を本発明と比較例を対比して示す。こ
れから明らかなように、比較例圧延Ｎｏ、Ｉｌでは、表
面異常相が発生するが、本発明法では、表面異常相の発
生が防止でき、さらに本発明の圧延まま材では、ベイナ
イト分率が５％以下に抑えられ、また硬さレベルは比較
例圧延Ｎ ｏ 、 Ｉｌｌの圧延まま材に比べて概ね）
ＩＶで１０以上軟化しており、この結果、「比較例圧延
Ｎｏ、ＩＩＩ （従来法）の圧延材−軟化焼鈍」材とほ
ぼ同等の軟質化レベルを達成している。Hardness was evaluated as an index of cold workability. Table 3 shows the material properties of each steel material, comparing the present invention and a comparative example. As is clear from this, abnormal surface phases occur in Comparative Example Rolled No. and Il, but in the method of the present invention, generation of surface abnormal phases can be prevented, and furthermore, in the as-rolled material of the present invention, it is clear that the bainite fraction is 5. % or less, and the hardness level is approximately equal to that of the as-rolled material of the comparative example rolled No.
It was softened by 10 or more in IV, and as a result, it achieved a softening level that was almost the same as that of the "Comparative Example Rolling No. III (Conventional Method) Rolled Material - Softening Annealing" material.
［発明の効果コ
以上延べたごとく、本発明を用いれば、熱間圧延ままで
表面異常相がなく、且つ従来の軟化焼鈍レベルの優れた
冷間加工性を保証し得る軟質線材の製造が可能であり、
自動車用部品、建設機械用部品等の製造に際して、冷間
加工の前の軟化焼鈍の省略が可能で、大幅な製造コスト
低減と生産性の向上が可能となり、産業上の効果は極め
て顕著なるものがある。[Effects of the invention] As described above, by using the present invention, it is possible to produce a soft wire rod that has no surface abnormal phases as hot-rolled and can guarantee excellent cold workability at the level of conventional softening annealing. and
When manufacturing automobile parts, construction machinery parts, etc., it is possible to omit softening annealing before cold working, making it possible to significantly reduce manufacturing costs and improve productivity, which has extremely significant industrial effects. There is.
他４名4 others
Claims (1)
的不純物からなる鋼を熱間圧延するに際して、 （Ａ）９００〜１２５０℃に加熱する工程と、（Ｂ）８
８０℃以上の温度範囲で総減面率５０％以上の圧延を行
う工程と、 （Ｃ）その後、８８０℃未満の温度範囲で、「減面率１
０％以上の圧延後、直ちに鋼材表面 温度が一旦Ｍｓ点〜７００℃となるように冷却し、引き
続いて減面率１０％以上の圧延を 行う」工程を１回以上有する工程で圧延を 行い、最終圧延出側の鋼材表面温度を７５０〜８８０℃
とする工程と、 （Ｄ）仕上げ圧延後、該線材の表面温度が７００〜８０
０℃となるように急冷した後捲取る工程と、 （Ｅ）その後コイル状で７００〜５００℃の温度範囲を
平均冷却速度で０．０５〜０．７℃／秒で冷却する工程
とを有してなることを特徴とす る圧延ままで表面異常相のない軟質線材の 製造方法。 ２ 鋼が、さらに、 Ｃｒ：１．５％以下、 Ｎｉ：３．５％以下、 Ｍｏ：１．０％以下、 Ｂ：０．００５％以下 の１種または２種以上を含有する、請求項１記載の圧延
ままで表面異常相のない軟質線材の製造方法。 ３ 鋼が、さらに、 Ｔｉ：０．００５〜０．０４％、 Ｎｂ：０．００５〜０．１％、 Ｖ：０．０３〜０．３％ の１種または２種以上を含有する、請求項 １または２記載の圧延ままで表面異常相のない軟質線材
の製造方法。[Claims] 1 Weight ratio: C: 0.10-0.50%, Si: 0.01-0.40%, Mn: 0.25-1.70%, S: 0.01-0.01% Contains 0.15%, Al: 0.015-0.05%, N: 0.003-0.020%, P: limited to 0.035% or less, and the remainder is iron and unavoidable impurities. When hot rolling the steel, (A) heating to 900 to 1250°C; (B) 8
A step of rolling with a total area reduction of 50% or more in a temperature range of 80°C or more; (C) Then, rolling with a total area reduction of 1
After rolling by 0% or more, the steel surface temperature is immediately cooled to the Ms point to 700°C, and then rolled with an area reduction of 10% or more. The surface temperature of the steel material on the final rolling exit side is 750 to 880℃.
(D) After finish rolling, the surface temperature of the wire is 700 to 80.
(E) A step of cooling the coil in the temperature range of 700 to 500 degrees Celsius at an average cooling rate of 0.05 to 0.7 degrees Celsius per second. A method for producing a soft wire rod without surface abnormal phases as rolled, characterized by: 2. Claim in which the steel further contains one or more of the following: Cr: 1.5% or less, Ni: 3.5% or less, Mo: 1.0% or less, B: 0.005% or less 1. The method for producing a soft wire rod having no surface abnormal phase as rolled according to 1. 3. A claim in which the steel further contains one or more of Ti: 0.005 to 0.04%, Nb: 0.005 to 0.1%, and V: 0.03 to 0.3%. 3. A method for producing a soft wire rod as described in item 1 or 2, which has no surface abnormal phase as rolled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14029090A JPH0713257B2 (en) | 1990-05-30 | 1990-05-30 | Method for manufacturing soft wire without as-rolled surface abnormal phase |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14029090A JPH0713257B2 (en) | 1990-05-30 | 1990-05-30 | Method for manufacturing soft wire without as-rolled surface abnormal phase |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0432514A true JPH0432514A (en) | 1992-02-04 |
| JPH0713257B2 JPH0713257B2 (en) | 1995-02-15 |
Family
ID=15265354
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14029090A Expired - Lifetime JPH0713257B2 (en) | 1990-05-30 | 1990-05-30 | Method for manufacturing soft wire without as-rolled surface abnormal phase |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0713257B2 (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100285258B1 (en) * | 1996-11-22 | 2001-04-02 | 이구택 | Spheroidizing method of high ally steel for wire rod |
| KR100398378B1 (en) * | 1998-10-13 | 2003-12-18 | 주식회사 포스코 | The method of manufacturing wire rods for the stabilizer of automobile |
| KR100398375B1 (en) * | 1998-08-27 | 2003-12-18 | 주식회사 포스코 | A method of manufacturing as-rolled wire rods for |
| KR100516516B1 (en) * | 2001-12-24 | 2005-09-26 | 주식회사 포스코 | A method for manufacturing spring steel without ferrite decarburization |
| JP2008007853A (en) * | 2006-05-31 | 2008-01-17 | Sumitomo Metal Ind Ltd | Rolled wire rod and production method therefor |
| KR101461763B1 (en) * | 2012-12-27 | 2014-11-13 | 주식회사 포스코 | Non-quenched and tempered steel wire rod having excellent toughness and manufacturing method thereof |
| KR101685824B1 (en) * | 2015-06-18 | 2016-12-12 | 현대제철 주식회사 | Wire rod for cold forging and method for manufacturing thereof |
| JP2018537584A (en) * | 2015-11-12 | 2018-12-20 | ポスコＰｏｓｃｏ | Non-tempered wire rod excellent in cold workability and manufacturing method thereof |
| JPWO2020230880A1 (en) * | 2019-05-16 | 2021-11-11 | 日本製鉄株式会社 | Steel wire and hot rolled wire |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3024066U (en) * | 1995-08-11 | 1996-05-17 | 株式会社三光化成 | Clothes hanger |
| KR101665799B1 (en) * | 2014-12-23 | 2016-10-13 | 주식회사 포스코 | Manufacturing method of boron steel wire |
| KR101758491B1 (en) * | 2015-12-17 | 2017-07-17 | 주식회사 포스코 | Non-quenched and tempered wire rod having excellent strength and cold workability and method for manufacturing same |
| KR101839240B1 (en) * | 2016-11-16 | 2018-03-16 | 주식회사 포스코 | High forming low-carbon wire rod having excellent cold workability and method for manufacturing same |
| KR102492631B1 (en) * | 2020-12-18 | 2023-01-30 | 주식회사 포스코 | Wire rod and parts for fastening with improved delayed fracture resisitance and method for manufacturing the same |
-
1990
- 1990-05-30 JP JP14029090A patent/JPH0713257B2/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100285258B1 (en) * | 1996-11-22 | 2001-04-02 | 이구택 | Spheroidizing method of high ally steel for wire rod |
| KR100398375B1 (en) * | 1998-08-27 | 2003-12-18 | 주식회사 포스코 | A method of manufacturing as-rolled wire rods for |
| KR100398378B1 (en) * | 1998-10-13 | 2003-12-18 | 주식회사 포스코 | The method of manufacturing wire rods for the stabilizer of automobile |
| KR100516516B1 (en) * | 2001-12-24 | 2005-09-26 | 주식회사 포스코 | A method for manufacturing spring steel without ferrite decarburization |
| JP2008007853A (en) * | 2006-05-31 | 2008-01-17 | Sumitomo Metal Ind Ltd | Rolled wire rod and production method therefor |
| KR101461763B1 (en) * | 2012-12-27 | 2014-11-13 | 주식회사 포스코 | Non-quenched and tempered steel wire rod having excellent toughness and manufacturing method thereof |
| KR101685824B1 (en) * | 2015-06-18 | 2016-12-12 | 현대제철 주식회사 | Wire rod for cold forging and method for manufacturing thereof |
| JP2018537584A (en) * | 2015-11-12 | 2018-12-20 | ポスコＰｏｓｃｏ | Non-tempered wire rod excellent in cold workability and manufacturing method thereof |
| JPWO2020230880A1 (en) * | 2019-05-16 | 2021-11-11 | 日本製鉄株式会社 | Steel wire and hot rolled wire |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0713257B2 (en) | 1995-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3554505B2 (en) | Hot-rolled wire rod / steel bar for machine structure and manufacturing method thereof | |
| JPH0432514A (en) | Production of soft wire rod free from surface abnormal phase in as-rolled state | |
| US9394580B2 (en) | High-toughness cold-drawn non-heat-treated wire rod, and method for manufacturing same | |
| JP3915460B2 (en) | High strength hot rolled steel sheet and method for producing the same | |
| JP3879440B2 (en) | Manufacturing method of high strength cold-rolled steel sheet | |
| KR20210108002A (en) | A wire rod free from heat treament having high toughness for cold forging and method for manufacturing the same | |
| JP3554506B2 (en) | Manufacturing method of hot-rolled wire and bar for machine structure | |
| JP3422865B2 (en) | Method for producing high-strength martensitic stainless steel member | |
| KR20000043762A (en) | Method of manufacturing super high-strength cold-rolled steel sheet improved in ductility | |
| CN112400033B (en) | Hot-rolled plated steel sheet having high strength, high formability, and excellent bake hardenability, and method for producing same | |
| JPH02213416A (en) | Production of steel bar with high ductility | |
| JPH09209039A (en) | Production of high strength cold rolled steel sheet excellent in deep drawability | |
| JPH0582458B2 (en) | ||
| JP2566068B2 (en) | Method for manufacturing steel bar with excellent cold workability | |
| KR100435466B1 (en) | A method for manufacturing p added extra low carbon cold rolled steel sheet with superior deep drawability | |
| KR100311785B1 (en) | Manufacturing method of alloy wire rod for cold forging | |
| JP3274028B2 (en) | Manufacturing method of non-heat treated high strength high toughness hot forged parts | |
| JPH0452229A (en) | Highly efficient production of cold rolled steel sheet extremely excellent in workability | |
| KR100325713B1 (en) | Method for manufacturing alloy steel wire rod and bar | |
| JPH0394020A (en) | Production of cold rolled steel sheet for deep drawing excellent in resistance to secondary working brittleness | |
| KR101736618B1 (en) | High strength steel wire rod and steel wire having excellent formability, and method for manufacturing thereof | |
| KR100554748B1 (en) | Method for manufacturing wire rods having superior strength for drawing | |
| KR101322080B1 (en) | High strength steel sheet with excellent coatability and method for manufacturing the same | |
| KR20090069880A (en) | High-strength hot rolled steel sheet having excellent stretch flangeability, ductility,and method for manufacturing the same | |
| JPS6259166B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080215 Year of fee payment: 13 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090215 Year of fee payment: 14 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090215 Year of fee payment: 14 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100215 Year of fee payment: 15 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100215 Year of fee payment: 15 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110215 Year of fee payment: 16 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110215 Year of fee payment: 16 |