JPH07268464A - Production of bainitic wire rod or steel wire for wiredrawing - Google Patents
Production of bainitic wire rod or steel wire for wiredrawingInfo
- Publication number
- JPH07268464A JPH07268464A JP6401394A JP6401394A JPH07268464A JP H07268464 A JPH07268464 A JP H07268464A JP 6401394 A JP6401394 A JP 6401394A JP 6401394 A JP6401394 A JP 6401394A JP H07268464 A JPH07268464 A JP H07268464A
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- JP
- Japan
- Prior art keywords
- wire
- steel
- wire rod
- temperature
- salt
- 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.)
- Pending
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- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、伸線加工用ベイナイト
線材または鋼線の製造方法に関するものである。本発明
において、製品としての線材とは鋼片を線材に圧延後に
直接熱処理を施して伸線加工用とした線材を意味し、製
品としての鋼線とは伸線加工前または熱間圧延後に、伸
線加工に供すべく熱処理を施した鋼線、および熱間圧延
後冷間加工により第１次引抜加工を施した後に、第２次
引抜加工用として熱処理を施した鋼線を意味する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a bainite wire rod or steel wire for wire drawing. In the present invention, a wire rod as a product means a wire rod for direct drawing by subjecting a steel slab to a heat treatment after being rolled into a wire rod, and a steel wire as a product is a wire rod before or after hot rolling, It means a steel wire that has been heat-treated to be subjected to wire drawing, and a steel wire that has been subjected to a first drawing process by hot working and then cold working and then a heat treatment for a second drawing process.
【０００２】[0002]
【従来の技術】通常、線材または鋼線は種々の最終製品
の用途に応じて、伸線加工されるが、この伸線加工の前
に、線材または鋼線を予め伸線加工に適した状態にして
おく必要がある。従来、高炭素鋼線材または鋼線に関し
ては、伸線加工前に組織を均一で微細なパーライトと少
量の初析フェライトの混合組織にする必要からパテンテ
ィングと呼ばれる線材または鋼線独特の熱処理が施され
る。これは線材または鋼線をオーステナイト化温度に加
熱した後、適度な冷却速度で冷却して、パーライト変態
を完了させて微細パーライトと少量の初析フェライトの
混合組織にする熱処理方法である。しかし、パーライト
組織では伸線加工工程において高減面率における延性の
劣化、捻回試験での割れの発生（以下デラミネーション
と称する）が問題となっている。2. Description of the Related Art Usually, wire rods or steel wires are drawn according to the use of various end products. Prior to this wire drawing, the wire rods or steel wires are suitable for wire drawing. Need to be kept. Conventionally, for high carbon steel wire or steel wire, it is necessary to make the structure uniform and a mixed structure of fine pearlite and a small amount of pro-eutectoid ferrite before wire drawing, so a heat treatment unique to wire or steel wire called patenting is performed. To be done. This is a heat treatment method in which a wire or steel wire is heated to an austenitizing temperature and then cooled at an appropriate cooling rate to complete the pearlite transformation and form a mixed structure of fine pearlite and a small amount of proeutectoid ferrite. However, in the pearlite structure, deterioration of ductility at a high area reduction rate in the wire drawing process and occurrence of cracks in the twisting test (hereinafter referred to as delamination) pose problems.
【０００３】特開平５−１１７７６２号公報記載の線材
の製造方法では、鋼片を９００〜１１００℃の範囲に加
熱した後、線材に圧延し、得られた線材を８５０〜５７
５℃の間を１００℃／ｓｅｃ以上の冷却速度で冷却し、
次いで４５０〜５００℃の温度範囲に、一定時間以上保
定することにより、ベイナイト線材とする熱処理を行っ
ており、線材組織をベイナイト組織にすることにより優
れた伸線加工性が得られるとしている。According to the method for manufacturing a wire rod described in Japanese Patent Laid-Open No. 5-117762, a steel slab is heated to a range of 900 to 1100 ° C. and then rolled into a wire rod, and the obtained wire rod is 850 to 57.
Cool between 5 ° C at a cooling rate of 100 ° C / sec or more,
Then, the bainite wire is heat-treated by keeping it in the temperature range of 450 to 500 ° C. for a certain period of time or more, and it is said that excellent wire drawing workability can be obtained by changing the wire structure to the bainite structure.
【０００４】しかし、線材圧延後のベイナイト線材を得
るために必要な冷却速度に関しては、それを実現するた
めの適正な冷却媒体に対する線径と冷媒温度の関係は明
確にはされていない。However, regarding the cooling rate required to obtain the bainite wire rod after the wire rod is rolled, the relationship between the wire diameter and the refrigerant temperature with respect to an appropriate cooling medium for realizing it has not been clarified.
【０００５】[0005]
【発明が解決しようとする課題】本発明は線材または鋼
線の熱処理工程において、前記の如き問題点を生じない
伸線加工性に優れた線材または鋼線の製造方法を提供す
ることを課題とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a wire rod or steel wire which is excellent in wire drawing workability and does not cause the above problems in the heat treatment step of the wire rod or steel wire. To do.
【０００６】[0006]
【課題を解決するための手段】本発明の前記の課題は、
本発明に従い特定量のＣ、Ｍｎ、Ｓｉおよび必要に応じ
てＣｒを含み、ＰおよびＳ量の上限値が制限された化学
組成からなる鋼片からの熱間圧延後の線材の冷却にあた
り、或いはオーステナイト化温度に加熱後の前記化学組
成からなる鋼線の熱処理において、カリウム硝酸塩系ま
たはナトリウム硝酸塩系塩を単独または複合して、３５
０℃以上５００℃を超えない温度範囲で線径により定ま
る一定温度以下に加熱溶融してなり、かつガス体による
攪拌下にある溶融塩に浸漬し、この温度範囲に一定時間
以上保定することにより、ベイナイト線材または鋼線が
安定的に製造可能になることにより解決される。The above-mentioned problems of the present invention are as follows.
According to the present invention, in cooling a wire rod after hot rolling from a steel slab containing a specific amount of C, Mn, Si and, if necessary, Cr, and having a chemical composition in which the upper limits of the amounts of P and S are limited, or In the heat treatment of the steel wire having the above chemical composition after heating to the austenitizing temperature, potassium nitrate-based or sodium nitrate-based salts are used alone or in combination,
By heating and melting below a certain temperature determined by the wire diameter in a temperature range of 0 ° C or more and not exceeding 500 ° C, and immersing in molten salt under stirring by a gas body, and holding in this temperature range for a certain time or more , A bainite wire or a steel wire can be stably manufactured.
【０００７】すなわち、本発明の要旨とするところは下
記のとおりである。 （１）重量％で Ｃ ： ０．８０〜０．９０％、Ｓｉ ： ０．１５
〜１．５０％、Ｍｎ ： ０．１０〜１．００％を含有
し、合金成分としてさらにＰ ： ０．０２％以下、
Ｓ ： ０．０１％以下、Ａｌ ： ０．００３％以
下に制限され、残部がＦｅおよび不可避的不純物からな
る組成の鋼片を線材に圧延後、１１００〜７５５℃の温
度範囲から、カリウム硝酸塩系またはナトリウム硝酸塩
系塩を単独または複合して、３５０℃以上５００℃を超
えない温度範囲で下記式（１）で定める温度Ｔに加熱溶
融してなり、かつガス体による攪拌下にある溶融塩に浸
漬し、この温度範囲に下記式（２）で定める時間Ｙ秒以
上保定することを特徴とする伸線加工用ベイナイト線材
の製造方法。That is, the gist of the present invention is as follows. (1) C: 0.80 to 0.90% by weight%, Si: 0.15
˜1.50%, Mn: 0.10 to 1.00%, and further P: 0.02% or less as an alloy component,
S: 0.01% or less, Al: 0.003% or less, and the balance is composed of Fe and inevitable impurities. After rolling a steel slab into a wire rod, a potassium nitrate system is used from a temperature range of 1100 to 755 ° C. Alternatively, a molten salt obtained by heating or melting a sodium nitrate salt alone or in combination to a temperature T determined by the following formula (1) in a temperature range of 350 ° C. or higher and not exceeding 500 ° C. and being stirred by a gas body A method for manufacturing a bainite wire rod for wire drawing, characterized by immersing and holding in this temperature range for a time of Y seconds or more defined by the following formula (2).
【０００８】Ｔ≦９５０−１００×Ｄ ・・・・（１） 但し、Ｄ：線材径（ｍｍφ） Ｙ＝ｅｘｐ（１９．８３−０．０３２９×Ｔ）・・・・（２） 但し、Ｔ：保定温度（℃） （２）出発鋼片が合金成分として、さらにＣｒ：０．１
０〜１．００％を含有する前項１記載の伸線加工用ベイ
ナイト線材の製造方法。T ≦ 950-100 × D (1) where D: wire diameter (mmφ) Y = exp (19.83-0.0329 × T) (2) where T : Holding temperature (° C) (2) The starting steel billet further contains Cr: 0.1 as an alloy component.
The method for producing a bainite wire rod for wire drawing according to the preceding item 1, containing 0 to 1.00%.
【０００９】（３）重量％で Ｃ ： ０．８０〜０．９０％、Ｓｉ ： ０．１５
〜１．５０％、Ｍｎ ： ０．１０〜１．００％を含有
し、合金成分としてさらにＰ ： ０．０２％以下、
Ｓ ： ０．０１％以下、Ａｌ ： ０．００３％以
下に制限され、残部がＦｅおよび不可避的不純物からな
る組成の鋼線を１１００〜７５５℃の温度範囲に加熱し
た後、カリウム硝酸塩系またはナトリウム硝酸塩系塩を
単独または複合して、３５０℃以上５００℃を超えない
温度範囲で下記式（１）で定める温度Ｔに加熱溶融して
なり、かつガス体による攪拌下にある溶融塩に浸漬し、
この温度範囲に下記式（２）で定める時間Ｙ秒以上保定
することを特徴とする伸線加工用ベイナイト鋼線の製造
方法。(3) C: 0.80 to 0.90% by weight, Si: 0.15
˜1.50%, Mn: 0.10 to 1.00%, and further P: 0.02% or less as an alloy component,
S: 0.01% or less, Al: 0.003% or less, and the balance is composed of Fe and unavoidable impurities. After heating a steel wire to a temperature range of 1100 to 755 ° C., potassium nitrate or sodium. A nitrate-based salt, alone or in combination, is heated and melted at a temperature T defined by the following formula (1) in a temperature range of 350 ° C. or higher and not higher than 500 ° C., and immersed in a molten salt under stirring by a gas body. ,
A method for producing a bainite steel wire for wire drawing, characterized by holding in this temperature range for a time of Y seconds or more defined by the following formula (2).
【００１０】Ｔ≦９５０−１００×Ｄ ・・・・（１） 但し、Ｄ：鋼線径（ｍｍφ） Ｙ＝ｅｘｐ（１９．８３−０．０３２９×Ｔ）・・・・（２） 但し、Ｔ：保定温度（℃） （４）出発鋼線が合金成分として、さらにＣｒ：０．１
０〜１．００％を含有する前項３記載の伸線加工用ベイ
ナイト鋼線の製造方法。T ≦ 950-100 × D (1) where D: Steel wire diameter (mmφ) Y = exp (19.83-0.0329 × T) (2) T: Holding temperature (° C) (4) The starting steel wire was used as an alloy component, and Cr: 0.1
The method for producing a bainitic steel wire for wire drawing according to the above item 3, containing 0 to 1.00%.
【００１１】[0011]
【作用】本発明における構成要件の限定理由について述
べる。出発鋼片及び鋼線の化学組成の限定理由は次のと
おりである。一次伸線性が著しく低下するのはＣの添加
量が０．８０ｗｔ％未満の時であるため、下限を０．８
０ｗｔ％とするが、０．９０ｗｔ％を超えて添加すると
中心偏析が生じるので上限を０．９０ｗｔ％とした。The reason for limiting the constituent features of the present invention will be described. The reasons for limiting the chemical composition of the starting billet and the steel wire are as follows. The primary drawability is remarkably reduced when the amount of C added is less than 0.80 wt%, so the lower limit is 0.8.
The content is 0 wt%, but if it exceeds 0.90 wt%, center segregation occurs, so the upper limit was made 0.90 wt%.
【００１２】Ｓｉは脱酸剤として０．１５ｗｔ％以上加
える。またＳｉは鋼を固溶強化する元素であるととも
に、鋼線のリラクセーションロスを低減できる元素であ
る。しかし、スケール生成量を減少させメカニカルデス
ケーリング性を悪くするほか、線材のボンデ潤滑性をや
や低下させる。そのため上限は１．５０ｗｔ％とした。
Ｍｎは脱酸剤として０．１０ｗｔ％以上加える。またＭ
ｎは鋼に固溶して強化する元素であるが、添加量を増加
させると線材中心部において偏析を生じやすくなる。偏
析部は焼入性が向上し変態終了時間が長時間側にずれる
ため、未変態部がマルテンサイトとなり伸線加工中の断
線につながる。そこでＭｎの上限は１．００ｗｔ％とし
た。Si is added at 0.15 wt% or more as a deoxidizing agent. In addition, Si is an element that solid-solution strengthens steel and is an element that can reduce relaxation loss of the steel wire. However, in addition to reducing the amount of scale generation and deteriorating mechanical descaling properties, it also slightly lowers the bonder lubricity of the wire. Therefore, the upper limit is set to 1.50 wt%.
Mn is added as a deoxidizer in an amount of 0.10 wt% or more. Also M
Although n is an element that forms a solid solution in steel to strengthen it, segregation tends to occur in the central portion of the wire when the amount of addition is increased. Since the segregated part has improved hardenability and the transformation end time shifts to the long side, the untransformed part becomes martensite, which leads to disconnection during wire drawing. Therefore, the upper limit of Mn is set to 1.00 wt%.
【００１３】本発明のような過共析鋼の場合、パテンテ
ィング後の組織においてセメンタイトのネットワークが
発生しやすくセメンタイトの厚みのあるものが析出しや
すい。本発明の鋼において高強度高延性を実現するため
には、セメンタイトネットワークや厚いセメンタイトを
なくす必要がある。Ｃｒはこのようなセメンタイトの異
常部の出現を抑制し、さらにパーライトを微細にする効
果を有するため、必要に応じて添加することが望まし
い。従って下限をその効果の期待できる０．１０ｗｔ％
とする。しかし、多量の添加は熱処理後のフェライト中
の転位密度を上昇させるため引き抜き加工後の極細線の
延性を著しく害することになる。従って、上限を延性を
害することのない１．００ｗｔ％とする。In the case of the hyper-eutectoid steel according to the present invention, a cementite network is likely to occur in the microstructure after patenting, and a cementite having a thickness is likely to precipitate. In order to achieve high strength and high ductility in the steel of the present invention, it is necessary to eliminate the cementite network and thick cementite. Cr has the effect of suppressing the appearance of such abnormal portions of cementite and further refining pearlite, so it is desirable to add it as necessary. Therefore, the lower limit is 0.10 wt% where the effect can be expected.
And However, a large amount of addition increases the dislocation density in the ferrite after heat treatment, and therefore significantly impairs the ductility of the ultrafine wire after drawing. Therefore, the upper limit is set to 1.00 wt% which does not impair the ductility.
【００１４】ＰおよびＳは、結晶粒界に析出し、鋼の特
性を劣化させるため、できる限り低く抑える必要があ
る。Ｐの上限は０．０２％、Ｓの上限は０．０１％とし
た。極細線の延性を低下させる原因としてはＡｌ
2 Ｏ3 ，ＭｇＯ−Ａｌ2 Ｏ3 等のＡｌ2 Ｏ3 を主成分と
する非金属介在物の存在がある。従って、本発明におい
ては非延性介在物による延性低下を避けるためＡｌ含有
量を０．００３ｗｔ％以下とする。P and S precipitate in the grain boundaries and deteriorate the properties of the steel, so they must be kept as low as possible. The upper limit of P was 0.02% and the upper limit of S was 0.01%. As a cause of reducing the ductility of extra fine wires, Al
There are non-metallic inclusions containing Al 2 O 3 as a main component, such as 2 O 3 and MgO—Al 2 O 3 . Therefore, in the present invention, the Al content is set to 0.003 wt% or less in order to avoid a decrease in ductility due to non-ductile inclusions.
【００１５】次に本発明のベイナイト線材および鋼線を
得るための圧延条件と熱処理条件について述べる。線材
圧延後の冷却開始温度または鋼線加熱温度を７５５〜１
１００℃としたのは、７５５℃がオーステナイト変態点
の下限であり、一方１１００℃を超えるとオーステナイ
ト粒の異常成長が生じるからである。Next, rolling conditions and heat treatment conditions for obtaining the bainite wire and steel wire of the present invention will be described. The cooling start temperature or steel wire heating temperature after wire rod rolling is 755 to 1
The reason why the temperature is 100 ° C. is that 755 ° C. is the lower limit of the austenite transformation point, while if it exceeds 1100 ° C., abnormal growth of austenite grains occurs.
【００１６】溶融塩の組成をカリウム硝酸塩系またはナ
トリウム硝酸塩系塩の単独または複合塩としたのは、他
の塩では線材の腐食が著しく、好ましくないためであ
る。また塩の融点が高くなると粘性が大きくなり、対流
が抑制されることによって塩の熱伝導性が低下する。こ
の点において硝酸カリウム、硝酸ナトリウムは共に融点
が４００℃以下であり、これらの塩を複合すれば４００
℃以下の範囲で、融点を調整することができる。The composition of the molten salt is potassium nitrate-based or sodium nitrate-based salt alone or as a complex salt, because the wire is not corroded remarkably with other salts, which is not preferable. Further, as the melting point of the salt increases, the viscosity increases, and convection is suppressed, so that the thermal conductivity of the salt decreases. In this respect, both potassium nitrate and sodium nitrate have melting points of 400 ° C. or lower, and if these salts are combined, they will be 400
The melting point can be adjusted within the range of ℃ or below.
【００１７】溶融塩の恒温保持温度範囲を３５０〜５０
０℃と定めた理由は、３５０℃が上部ベイナイト組織生
成の下限温度であり、他方５００℃が上部ベイナイト組
織生成の上限温度であるからである。３５０℃以上５０
０℃を超えない温度範囲での溶融塩温度の上限は、線材
および鋼線の線径に依存する。ベイナイト組織生成に
は、臨界冷却速度６０℃／ｓｅｃ以上の冷却速度を得る
必要がある。このため線径が太い場合は溶融塩温度を低
くし、冷却速度を臨界冷却速度以上にする必要があるの
で、溶融塩の加熱温度をを下記（１）式で定める温度Ｔ
（℃）とした。The constant temperature holding temperature range of the molten salt is set to 350 to 50.
The reason for defining 0 ° C. is that 350 ° C. is the lower limit temperature for forming the upper bainite structure, while 500 ° C. is the upper limit temperature for forming the upper bainite structure. 350 ° C or higher 50
The upper limit of the molten salt temperature in the temperature range not exceeding 0 ° C depends on the wire diameter of the wire rod and the steel wire. In order to generate the bainite structure, it is necessary to obtain a critical cooling rate of 60 ° C./sec or more. For this reason, when the wire diameter is large, it is necessary to lower the molten salt temperature and set the cooling rate to the critical cooling rate or higher. Therefore, the heating temperature of the molten salt is set to the temperature T determined by the following formula (1).
(° C).
【００１８】Ｔ≦９５０−１００×Ｄ ・・・・（１） 但し、Ｄ：線材または鋼線径（ｍｍφ） ３５０〜５００℃間の温度範囲での恒温保持に必要な時
間はＴＴＴ線図の変態終了線から求められるが、冷却槽
での浸漬時間が不十分な場合マルテンサイトが発生し、
伸線加工中の断線の原因となる。そこで変態終了時間以
上に保持する必要があるので、３５０〜５００℃の温度
範囲に保持する時間の下限を下記（２）式で定める時間
Ｙ秒とした。T ≦ 950-100 × D (1) However, D: wire rod or steel wire diameter (mmφ) The time required for constant temperature keeping in the temperature range of 350 to 500 ° C. is as shown in the TTT diagram. Obtained from the transformation end line, martensite occurs when the immersion time in the cooling tank is insufficient,
It may cause wire breakage during wire drawing. Therefore, since it is necessary to maintain the temperature for not less than the transformation end time, the lower limit of the time for maintaining in the temperature range of 350 to 500 ° C. is set to the time Y seconds defined by the following formula (2).
【００１９】 Ｙ＝ｅｘｐ（１９．８３−０．０３２９×Ｔ）・・・・（２） 但し、Ｔ：熱処理温度（℃）Y = exp (19.83-0.0329 × T) ... (2) where T: heat treatment temperature (° C.)
【００２０】[0020]
実施例１ 表１に供試鋼の化学成分を示す。表１のＡ〜Ｄは本発明
鋼の例、ＥおよびＦは比較鋼の例である。Ｅ鋼はＣ量が
上限以上、Ｆ鋼はＭｎ量が上限以上である。Example 1 Table 1 shows the chemical composition of the test steel. A to D in Table 1 are examples of the steels of the present invention, and E and F are examples of comparative steels. The E steel has a C content of at least the upper limit, and the F steel has a Mn content of at least the upper limit.
【００２１】これらの供試鋼を連続鋳造設備により３０
０×５００ｍｍ鋳片とし、さらに分塊圧延により１２２
ｍｍ角断面の鋼片を製造した。これらの鋼片を表２に示
す直径の線材に圧延し、ＤＬＰ（Ｄｉｒｅｃｔ Ｌｅａ
ｄ Ｐａｔｅｎｔｉｎｇ）冷却を行なった。これらの線
材を平均減面率１７％で１．００ｍｍφまで伸線し、引
張試験、捻回試験を行った。These test steels were continuously cast at 30
0x500mm slab and 122 by slab rolling
A steel piece having a mm-square cross section was manufactured. These steel slabs were rolled into wire rods having the diameters shown in Table 2, and DLP (Direct Lea) was rolled.
d Patenting) Cooling was performed. These wire rods were drawn to 1.00 mmφ with an average surface reduction rate of 17%, and subjected to a tensile test and a twist test.
【００２２】引張試験はＪＩＳＺ２２０１の２号試験片
を用い、ＪＩＳＺ２２４１記載の方法で行った。捻回試
験は試験片長さ１００ｄ＋１００に切断後、チャック間
距離１００ｄ、回転速度１０ｒｐｍで破断するまで回転
させた。ｄは鋼線の直径を表わす。このようにして得ら
れた線材の特性値を表２に併せて示す。The tensile test was carried out by using the JISZ2201 No. 2 test piece according to the method described in JISZ2241. In the twist test, the test piece was cut to a length of 100d + 100, and then rotated at a distance between chucks of 100d and a rotation speed of 10 rpm until it was broken. d represents the diameter of the steel wire. The characteristic values of the wire rod thus obtained are also shown in Table 2.
【００２３】Ｎｏ．１〜Ｎｏ．４までは本発明例であ
り、本発明の熱処理条件を全て満たしているので、伸線
後１．０ｍｍφにおいてもデラミネーションが発生せず
伸線可能である。Ｎｏ．５〜Ｎｏ．１０は比較例であ
る。Ｎｏ．５は溶融塩温度が高すぎたために冷却速度が
遅くなり、ベイナイト組織生成せず、伸線加工性が低下
し、伸線途中で断線が生じた。No. 1-No. Up to 4 are examples of the present invention, and all the heat treatment conditions of the present invention are satisfied, so that delamination does not occur even after 1.0 mmφ after drawing and wire drawing is possible. No. 5 to No. 10 is a comparative example. No. In No. 5, since the molten salt temperature was too high, the cooling rate was slow, the bainite structure was not formed, wire drawability was deteriorated, and wire breakage occurred during wire drawing.
【００２４】Ｎｏ．６は恒温変態温度が高すぎたために
パーライトが生成し、伸線加工性が低下し、伸線途中で
断線が生じた。Ｎｏ．７は冷却開始温度が低かったため
にベイナイト組織が生成せず、伸線加工性が低下し、伸
線途中で断線が生じた。Ｎｏ．８は線径が太すぎたため
に、冷却速度が遅くなり、ベイナイト組織が生成せず、
伸線加工性が低下し、伸線途中で断線が生じた。No. In No. 6, pearlite was generated because the isothermal transformation temperature was too high, the wire drawing workability was deteriorated, and wire breakage occurred during wire drawing. No. Since No. 7 had a low cooling start temperature, a bainite structure was not formed, wire drawability was deteriorated, and wire breakage occurred during wire drawing. No. In No. 8, since the wire diameter was too thick, the cooling rate slowed down and the bainite structure was not formed,
Wire drawing workability deteriorated, and wire breakage occurred during wire drawing.
【００２５】Ｎｏ．９はＣ量が高すぎたため初析セメン
タイトが発生し、伸線加工性が低下した。Ｎｏ．１０は
Ｍｎ量が高すぎたため中心偏析に伴うミクロマルテンサ
イトが発生し、伸線加工性が低下した。 実施例２ 表３に供試鋼の化学成分を示す。No. In No. 9, since the C content was too high, pro-eutectoid cementite was generated and the wire drawing workability was deteriorated. No. In No. 10, since the amount of Mn was too high, micro martensite was generated due to center segregation, and wire drawability was deteriorated. Example 2 Table 3 shows the chemical composition of the sample steel.
【００２６】表３のＡ〜Ｄは本発明鋼の例、ＥおよびＦ
は比較鋼の例である。Ｅ鋼はＣ量が上限以上、Ｆ鋼はＭ
ｎ量が上限以上である。これらの鋼線を表４に示す条件
でオーステナイト化温度に加熱して、熱処理した後、平
均減面率１７％で１．００ｍｍφまで伸線し、引張試
験、捻回試験を行った。Tables A to D are examples of the steels of the present invention, E and F.
Are examples of comparative steels. E steel has a C content above the upper limit, and F steel has M
The n amount is not less than the upper limit. These steel wires were heated to an austenitizing temperature under the conditions shown in Table 4 and heat-treated, and then drawn to 1.00 mmφ with an average surface reduction rate of 17%, and a tensile test and a twist test were performed.
【００２７】引張試験はＪＩＳＺ２２０１の２号試験片
を用い、ＪＩＳＺ２２４１記載の方法で行なった。捻回
試験は試験片長さ１００ｄ＋１００に切断後、チャック
間距離１００ｄ、回転速度１０ｒｐｍで破断するまで回
転させた。ｄは鋼線の直径を表わす。このようにして得
られた鋼線の特性値を表４に併わせて示す。The tensile test was carried out by using the JISZ2201 No. 2 test piece according to the method described in JISZ2241. In the twist test, the test piece was cut to a length of 100d + 100, and then rotated at a distance between chucks of 100d and a rotation speed of 10 rpm until it was broken. d represents the diameter of the steel wire. The characteristic values of the steel wire thus obtained are also shown in Table 4.
【００２８】Ｎｏ．１〜Ｎｏ．４までは本発明例であ
り、本発明の熱処理条件を全て満たしているので、伸線
後１．０ｍｍφにおいてもデラミネーションが発生せず
伸線可能である。Ｎｏ．５〜Ｎｏ．１０は比較例であ
る。Ｎｏ．５は溶融塩温度が高すぎたために冷却速度が
遅くなり、ベイナイト組織が生成せず、伸線加工性が低
下し、伸線途中で断線が生じた。No. 1-No. Up to 4 are examples of the present invention, and all the heat treatment conditions of the present invention are satisfied, so that delamination does not occur even after 1.0 mmφ after drawing and wire drawing is possible. No. 5 to No. 10 is a comparative example. No. In No. 5, since the molten salt temperature was too high, the cooling rate was slow, a bainite structure was not formed, wire drawability was deteriorated, and wire breakage occurred during wire drawing.
【００２９】Ｎｏ．６は恒温変態温度が高すぎたために
パーライトが生成し、伸線加工性が低下し、伸線途中で
断線が生じた。Ｎｏ．７は冷却開始温度が低かったため
にベイナイト組織が生成せず、伸線加工性が低下し、伸
線途中で断線が生じた。Ｎｏ．８は線径が太すぎたため
に、冷却速度が遅くなり、ベイナイト組織が生成せず、
伸線加工性が低下し、伸線途中で断線が生じた。No. In No. 6, pearlite was generated because the isothermal transformation temperature was too high, the wire drawing workability was deteriorated, and wire breakage occurred during wire drawing. No. Since No. 7 had a low cooling start temperature, a bainite structure was not formed, wire drawability was deteriorated, and wire breakage occurred during wire drawing. No. In No. 8, since the wire diameter was too thick, the cooling rate slowed down and the bainite structure was not formed,
Wire drawing workability deteriorated, and wire breakage occurred during wire drawing.
【００３０】Ｎｏ．９はＣ量が高すぎたため初析セメン
タイトが発生し、伸線加工性が低下した。Ｎｏ．１０は
Ｍｎ量が高すぎたため中心偏析に伴うミクロマルテンサ
イトが発生し、伸線加工性が低下した。No. In No. 9, since the C content was too high, pro-eutectoid cementite was generated and the wire drawing workability was deteriorated. No. In No. 10, since the amount of Mn was too high, micro martensite was generated due to center segregation, and wire drawability was deteriorated.
【００３１】[0031]
【表１】 [Table 1]
【００３２】[0032]
【表２】 [Table 2]
【００３３】[0033]
【表３】 [Table 3]
【００３４】[0034]
【表４】 [Table 4]
【００３５】[0035]
【発明の効果】以上述べた如く本発明によれば、線材ま
たは鋼線に、従来法にくらべてより安定的にベイナイト
組織を生成させることが可能であるので、伸線加工性に
優れたベイナイト線材または鋼線を有利に提供するする
ことができる。As described above, according to the present invention, it is possible to more stably generate a bainite structure in a wire rod or a steel wire as compared with the conventional method. Therefore, bainite excellent in wire drawing workability can be obtained. Wire or steel wire can be advantageously provided.
【図１】本発明の熱処理パターンを示す図である。FIG. 1 is a diagram showing a heat treatment pattern of the present invention.
Claims (4)
組成の鋼片を線材に圧延後、１１００〜７５５℃の温度
範囲から、カリウム硝酸塩系またはナトリウム硝酸塩系
塩を単独または複合して、３５０℃以上５００℃を超え
ない温度範囲で下記式（１）で定める温度Ｔに加熱溶融
してなり、かつガス体による攪拌下にある溶融塩に浸漬
し、この温度範囲に下記式（２）で定める時間Ｙ秒以上
保定することを特徴とする伸線加工用ベイナイト線材の
製造方法。 Ｔ≦９５０−１００×Ｄ ・・・・（１） 但し、Ｄ：線材径（ｍｍφ） Ｙ＝ｅｘｐ（１９．８３−０．０３２９×Ｔ）・・・・（２） 但し、Ｔ：保定温度（℃）1. By weight%, C: 0.80 to 0.90%, Si: 0.15 to 1.50%, Mn: 0.10 to 1.00% are contained, and further P: 0.02% or less, S: 0.01% or less, Al: 0.003% or less, and a balance of Fe and unavoidable impurities in the balance. From the range, potassium nitrate-based salt or sodium nitrate-based salt is used alone or in combination, and is heated and melted to a temperature T defined by the following formula (1) within a temperature range of 350 ° C. or higher and 500 ° C. or less, and stirring by a gas body A method for producing a bainite wire rod for wire drawing, which comprises immersing in a molten salt underneath and holding in this temperature range for a time Y seconds or more defined by the following formula (2). T ≦ 950-100 × D (1) where D: wire diameter (mmφ) Y = exp (19.83-0.0329 × T) (2) where T: holding temperature (℃)
ｒ：０．１０〜１．００％を含有する請求項１記載の伸
線加工用ベイナイト線材の製造方法。2. The starting steel billet is used as an alloy component, and further C
The method for producing a bainite wire rod for wire drawing according to claim 1, containing r: 0.10 to 1.00%.
組成の鋼線を１１００〜７５５℃の温度範囲に加熱した
後、カリウム硝酸塩系またはナトリウム硝酸塩系塩を単
独または複合して、３５０℃以上５００℃を超えない温
度範囲で下記式（１）で定める温度Ｔに加熱溶融してな
り、かつガス体による攪拌下にある溶融塩に浸漬し、こ
の温度範囲に下記式（２）で定める時間Ｙ秒以上保定す
ることを特徴とする伸線加工用ベイナイト鋼線の製造方
法。 Ｔ≦９５０−１００×Ｄ ・・・・（１） 但し、Ｄ：鋼線径（ｍｍφ） Ｙ＝ｅｘｐ（１９．８３−０．０３２９×Ｔ）・・・・（２） 但し、Ｔ：保定温度（℃）3. C: 0.80 to 0.90% by weight%, Si: 0.15 to 1.50%, Mn: 0.10 to 1.00%, and further P: as an alloy component. 0.02% or less, S: 0.01% or less, Al: 0.003% or less, and after heating a steel wire having a composition of balance Fe and inevitable impurities to a temperature range of 1100 to 755 ° C. , Potassium nitrate salt or sodium nitrate salt alone or in combination, and heated and melted at a temperature T defined by the following formula (1) in a temperature range of 350 ° C. or higher and not higher than 500 ° C., and under stirring by a gas body. A method for producing a bainite steel wire for wire drawing, characterized by immersing in a certain molten salt and holding in this temperature range for a time of Y seconds or more defined by the following formula (2). T ≦ 950-100 × D (1) However, D: Steel wire diameter (mmφ) Y = exp (19.83-0.0329 × T) (2) However, T: Restoration Temperature (℃)
ｒ：０．１０〜１．００％を含有する請求項３記載の伸
線加工用ベイナイト鋼線の製造方法。4. The starting steel wire as an alloy component, and further C
The method for producing a bainitic steel wire for wire drawing according to claim 3, wherein r: 0.10 to 1.00% is contained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6401394A JPH07268464A (en) | 1994-03-31 | 1994-03-31 | Production of bainitic wire rod or steel wire for wiredrawing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6401394A JPH07268464A (en) | 1994-03-31 | 1994-03-31 | Production of bainitic wire rod or steel wire for wiredrawing |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07268464A true JPH07268464A (en) | 1995-10-17 |
Family
ID=13245873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6401394A Pending JPH07268464A (en) | 1994-03-31 | 1994-03-31 | Production of bainitic wire rod or steel wire for wiredrawing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07268464A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2018059193A (en) * | 2016-10-03 | 2018-04-12 | 新日鐵住金株式会社 | Manufacturing method of high strength low alloy steel material |
| CN111172469A (en) * | 2020-01-08 | 2020-05-19 | 柳州钢铁股份有限公司 | SWRH82B wire rod with low acid-soluble aluminum content |
| CN111206177A (en) * | 2020-01-08 | 2020-05-29 | 柳州钢铁股份有限公司 | Production method of SWRH82B steel with low acid-soluble aluminum content |
| WO2022143363A1 (en) * | 2020-12-31 | 2022-07-07 | 苏州骐骥焊接材料有限公司 | Zr-containing welding wire steel hot-rolled wire rod and production process therefor |
-
1994
- 1994-03-31 JP JP6401394A patent/JPH07268464A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2018059193A (en) * | 2016-10-03 | 2018-04-12 | 新日鐵住金株式会社 | Manufacturing method of high strength low alloy steel material |
| CN111172469A (en) * | 2020-01-08 | 2020-05-19 | 柳州钢铁股份有限公司 | SWRH82B wire rod with low acid-soluble aluminum content |
| CN111206177A (en) * | 2020-01-08 | 2020-05-29 | 柳州钢铁股份有限公司 | Production method of SWRH82B steel with low acid-soluble aluminum content |
| CN111206177B (en) * | 2020-01-08 | 2021-11-12 | 柳州钢铁股份有限公司 | Production method of SWRH82B steel with low acid-soluble aluminum content |
| CN111172469B (en) * | 2020-01-08 | 2021-11-12 | 柳州钢铁股份有限公司 | SWRH82B wire rod with low acid-soluble aluminum content |
| WO2022143363A1 (en) * | 2020-12-31 | 2022-07-07 | 苏州骐骥焊接材料有限公司 | Zr-containing welding wire steel hot-rolled wire rod and production process therefor |
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