JP2000204414A - Production of medium carbon steel - Google Patents

Production of medium carbon steel

Info

Publication number
JP2000204414A
JP2000204414A JP11007756A JP775699A JP2000204414A JP 2000204414 A JP2000204414 A JP 2000204414A JP 11007756 A JP11007756 A JP 11007756A JP 775699 A JP775699 A JP 775699A JP 2000204414 A JP2000204414 A JP 2000204414A
Authority
JP
Japan
Prior art keywords
carbon steel
toughness
less
medium carbon
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
Application number
JP11007756A
Other languages
Japanese (ja)
Other versions
JP3544131B2 (en
Inventor
Yukihiro Mukoda
行宏 向田
Takashi Shibata
尚 柴田
Shuzo Ono
秀三 小野
Yasuhiko Tanaka
泰彦 田中
Toru Ishiguro
徹 石黒
Original Assignee
Japan Steel Works Ltd:The
株式会社日本製鋼所
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Japan Steel Works Ltd:The, 株式会社日本製鋼所 filed Critical Japan Steel Works Ltd:The
Priority to JP00775699A priority Critical patent/JP3544131B2/en
Publication of JP2000204414A publication Critical patent/JP2000204414A/en
Application granted granted Critical
Publication of JP3544131B2 publication Critical patent/JP3544131B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To produce medium carbon steel excellent in both strength and toughness. SOLUTION: In the process of cooling from forging, steel is transformed into pearlite in the pearlite transform temp. region, is moreover subjected to normalizing treatment at the temp. of >= the Ac3 point for one or more times, is thereafter heated to the temp. of >= the Ac3 point, is quenched and is subsequently subjected to tempering for one or more times. As its compsn., the one contg., by weight, 0.25 to 0.55% C, 2.0 to 10.0% Cr, <=2.0% Si, <=2.0% Mn, <=4.0% Ni (1/2W+Mo): <=6.0% alone or in combination of W and Mo, >=2.0% V and <=0.20% Nb is shown. The elimination of netlike carbides deteriorating the refining of the structure and its toughness is made possible, and the toughness can remarkably be improved without deteriorating its strength.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION
【0001】[0001]
【発明の属する技術分野】本発明は、中炭素鋼の製造方
法に関するものであり、特に大型材の製造に好適な製造
方法に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing medium carbon steel, and more particularly to a method suitable for producing large-sized materials.
【0002】[0002]
【従来の技術及び発明が解決しようとする課題】従来、
中炭素鋼を製造する際には、所望の形状に鍛錬した後、
Ac点以上の温度で焼鈍処理を行った後、焼入れし、
さらに、1回以上の焼戻しを行っている。また、この製
造においては、組成の選定等により靱性を改善する手段
が講じられており、ある程度の成果を得ている。しか
し、中炭素鋼を材料として使用する製品で要求される強
度は益々上昇しており、それに相反する性質である靱性
においても一層の向上が望まれている。靱性の改善に
は、結晶粒の微細化が有効であることが知られており、
上記のように組成の選定により結晶粒を微細化する方法
が採られているが、組成の選定のみでは靱性をさらに向
上させるのは困難である。本発明は、上記事情を背景と
してなされたものであり、中炭素鋼において製造工程上
の工夫により結晶粒を微細化して、靱性をさらに向上さ
せることができる製造方法を提供することを目的とする
ものである。
2. Description of the Related Art
When manufacturing medium carbon steel, after forging to the desired shape,
Ac After annealing at a temperature of one or more points, quenching
Further, tempering is performed one or more times. In addition, in this production, measures have been taken to improve the toughness by selecting the composition and the like, and some results have been obtained. However, the strength required for products using medium carbon steel as a material is increasing, and further improvement in toughness, a contradictory property, is desired. It is known that refinement of crystal grains is effective in improving toughness.
As described above, a method of refining crystal grains by selecting a composition is employed, but it is difficult to further improve toughness only by selecting a composition. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manufacturing method capable of further improving toughness by refining crystal grains by devising a manufacturing process in a medium carbon steel. Things.
【0003】[0003]
【課題を解決するための手段】上記課題を解決するため
本発明の中炭素鋼の製造方法のうち第一の発明は、中炭
素鋼を鍛錬からの冷却途中にパーライト変態温度域で組
織をパーライト変態させ、さらにAc点以上の温度で
1回以上の焼準処理を施した後、Ac点以上の温度に
加熱して焼入れし、その後、焼戻しを1回以上施すこと
を特徴とする。
Means for Solving the Problems In order to solve the above-mentioned problems, the first invention of the method for producing medium carbon steel according to the present invention is to provide a method for manufacturing a medium carbon steel in a pearlite transformation temperature range during cooling from forging. It was transformed, after further subjected to one or more normalizing treatment with Ac 3 point or higher, quenching by heating to a temperature of more than three points Ac, then characterized by applying tempering or more times.
【0004】第二の発明の中炭素鋼の製造方法は、第一
の発明において、中炭素鋼の組成が重量%で、C:0.
25〜0.55%、Cr:2.0〜10.0%を含有
し、残部がFeおよび不可避的不純物からなることを特
徴とする。
[0004] A second invention provides a method for producing medium-carbon steel according to the first invention, wherein the composition of the medium-carbon steel is% by weight, and C: 0.
25 to 0.55%, Cr: 2.0 to 10.0%, the balance being Fe and unavoidable impurities.
【0005】第三の発明の中炭素鋼の製造方法は、第一
の発明において、中炭素鋼の組成が重量%で、C:0.
25〜0.55%、Cr:2.0〜10.0%、Si:
2.0%以下、Mn:2.0%以下、Ni:4.0%以
下、WおよびMoの単独又は複合で、(1/2W+M
o):6.0%以下、V:2.0%以下、Nb:0.2
0%以下を含有し、残部がFeおよび不可避的不純物か
らなることを特徴とする。
[0005] A third invention is a method for producing medium carbon steel according to the first invention, wherein the composition of the medium carbon steel is C: O.
25 to 0.55%, Cr: 2.0 to 10.0%, Si:
2.0% or less, Mn: 2.0% or less, Ni: 4.0% or less, W or Mo alone or in combination, ((W + M
o): 6.0% or less, V: 2.0% or less, Nb: 0.2
0% or less, with the balance being Fe and unavoidable impurities.
【0006】ここで、本発明に至った経緯について以下
に説明する。本発明者は、中炭素鋼の靱性に及ぼす結晶
粒サイズの影響について検討を重ねた。その結果、靱性
改善には結晶粒の微細化が効果的であることを見出し
た。そこで、結晶粒微細化について更なる検討を加え
た。その結果、鍛錬後、焼入れ前の熱処理条件によって
焼入れ後の結晶粒が変化することが判明した。この現象
に関して詳細に解析したところ、結晶粒微細化には焼入
れ前熱処理としてパーライト化処理が効果的であること
が明らかとなった。しかし、パーライト組織にはネット
状炭化物が析出し、それが焼入れ後まで残存すると靱性
低下を招くことも同時に判明した。次いで、ネット状炭
化物を消失させるための更なる検討を加えた。その結
果、パーライト化処理後さらにAc点以上の温度で焼
準処理を施すことで、ネット状炭化物は消失することが
判明した。また、焼準処理でネット状炭化物を消失させ
ることによって、後工程の焼入れ処理で微細炭化物が均
一に分散析出した安定した組織が得られ、靱性が著しく
向上することが明らかとなり、本発明を完成するに至っ
た。
Here, the background to the present invention will be described below. The present inventors have repeatedly studied the effect of the grain size on the toughness of the medium carbon steel. As a result, they have found that refinement of crystal grains is effective for improving toughness. Therefore, further investigation was made on the refinement of crystal grains. As a result, it was found that the crystal grains after quenching changed depending on the heat treatment conditions before quenching and after quenching. A detailed analysis of this phenomenon revealed that pearlite treatment was effective as a heat treatment before quenching for grain refinement. However, it has also been found that net-like carbides precipitate in the pearlite structure, and if they remain until after quenching, the toughness is reduced. Then, further investigation for eliminating the net-like carbide was added. As a result, it was found that the net carbides disappeared by performing normalizing treatment at a temperature of three or more Ac after the pearlitizing treatment. Further, by eliminating the net-like carbides in the normalizing treatment, a stable structure in which fine carbides are uniformly dispersed and precipitated in the subsequent quenching treatment is obtained, and it is clear that the toughness is remarkably improved. I came to.
【0007】以下に、製造工程における処理条件につい
て説明する。 (パーライト化処理)鍛錬後の冷却途中にパーライト変
態温度域で保持して、組織をパーライト変態させること
によって、その後のオーステナイト化時に結晶粒が著し
く微細化する。パーライト変態温度域は、中炭素鋼の組
成によって異なるため、該組成に従って保持温度を定め
るが、例えば650〜750℃の温度域を代表的に示す
ことができる。なお、保持時間は、パーライト変態開始
後、変態終了まで保持するのが望ましい。
Hereinafter, processing conditions in the manufacturing process will be described. (Pearlite-forming treatment) By maintaining the temperature in the pearlite transformation temperature range during cooling after forging and transforming the structure to pearlite, the crystal grains are remarkably refined during the subsequent austenitization. Since the pearlite transformation temperature range varies depending on the composition of the medium carbon steel, the holding temperature is determined according to the composition. However, for example, a temperature range of 650 to 750 ° C. can be representatively shown. It is desirable that the holding time be maintained from the start of the pearlite transformation to the end of the transformation.
【0008】(焼準処理)パーライト化処理後、さらに
Ac点以上の温度で焼準処理を施すことにより、後工
程の焼入れ処理において、ネット状炭化物が存在しな
い、細粒かつ安定した組織を得ることができる。この焼
準処理でネット状炭化物を消失させないと焼入れ後にも
ネット状炭化物が残存して靱性を低下させる原因となる
ので、焼準処理ではネット状炭化物を消失させる必要が
ある。また、オーステナイト結晶粒粗大化温度を越える
とオーステナイト結晶粒が粗大化して靱性が低下するの
でオーステナイト結晶粒粗大化温度未満に限定するのが
望ましい。これらの温度も中炭素鋼の組成によって異な
るため一義的に定めることはできず、該組成に従って適
宜保持温度を定めるが、例えばAc点温度として75
0〜850℃、オーステナイト結晶粒粗大化温度とし
て、1070〜1120℃を代表的に示すことができ
る。
(Normalizing treatment) After the pearlitizing treatment, a normalizing treatment is further performed at a temperature of three or more Ac, so that a fine-grained and stable structure free of net-like carbides can be obtained in a subsequent quenching treatment. Obtainable. If the net-like carbide is not eliminated by this normalizing treatment, the net-like carbide remains even after quenching and causes toughness to be reduced. Therefore, it is necessary to eliminate the net-like carbide in the normalizing treatment. If the temperature exceeds the austenite crystal grain coarsening temperature, the austenite crystal grains become coarse and the toughness is reduced. Therefore, it is desirable to limit the temperature to below the austenite crystal grain coarsening temperature. These temperatures can not be defined for uniquely different depending on the composition of the medium carbon steel, defining an appropriate holding temperature in accordance with the composition, but for example as Ac 3 point temperature 75
0 to 850 ° C. and a typical austenite crystal coarsening temperature of 1070 to 1120 ° C.
【0009】(焼入れ加熱温度)オーステナイト化温度
は、Ac点以上でないと安定した組織が得られない。
また、オーステナイト結晶粒粗大化温度を越えるとオー
ステナイト結晶粒が粗大化して靱性が低下するのでオー
ステナイト結晶粒粗大化温度未満に限定する。 (焼戻し温度)焼戻しを一回以上施すことによって、所
望の強度を得ることができる。なお、焼戻しは常法によ
り行うことができる。
(Heat Quenching Temperature) A stable structure cannot be obtained unless the austenitizing temperature is 3 or more Ac.
If the temperature exceeds the austenite crystal grain coarsening temperature, the austenite crystal grains become coarse and the toughness decreases, so the temperature is limited to less than the austenite crystal grain coarsening temperature. (Tempering temperature) A desired strength can be obtained by performing tempering one or more times. In addition, tempering can be performed by a conventional method.
【0010】また、第2、第3の発明に示された組成
は、上記製造方法への適用に好適であって上記効果が顕
著に得られ、靱性に優れた中炭素鋼が得られる。以下に
組成限定理由について説明する。なお、以下ではいずれ
も重量%を示している。 C:0.25〜0.55% Cは、焼入れ時におけるオーステナイト層を安定にし、
さらに炭化物を生成して引張強さを高める。所望の硬さ
を得るためには、0.25%以上含有させることが必要
であるが、0.55%を越えると炭化物が過剰となり、
靱性を低下させるのでその含有量は0.25〜0.55
%に限定する。さらに好ましい上下限は上記と同様の理
由で、下限が0.35越%、上限が0.45%である。
Further, the compositions shown in the second and third inventions are suitable for application to the above-mentioned manufacturing method, the above-mentioned effects are remarkably obtained, and a medium-carbon steel excellent in toughness is obtained. The reasons for limiting the composition will be described below. In addition, below, all show the weight%. C: 0.25 to 0.55% C stabilizes the austenite layer during quenching,
Further, carbides are formed to increase the tensile strength. In order to obtain the desired hardness, it is necessary to contain 0.25% or more, but if it exceeds 0.55%, the carbide becomes excessive,
Its content is 0.25 to 0.55 because it reduces toughness.
%. More preferable upper and lower limits are, for the same reason as described above, the lower limit is 0.35% and the upper limit is 0.45%.
【0011】Cr:2.0〜10.0% Crは鋼の焼入性を増し、引張強さや靱性の向上を図る
のに有効な元素である。その目的のためには2.0%以
上の含有が必要であるが、10.0%を越えると逆に靱
性が低下するのでその含有量を2.0〜10.0%に定
める。さらに好ましい上下限は上記と同様の理由で、下
限が3.0%越、上限が8.0%である。
Cr: 2.0 to 10.0% Cr is an element effective for increasing the hardenability of steel and improving the tensile strength and toughness. For that purpose, a content of 2.0% or more is necessary. However, if it exceeds 10.0%, the toughness is reduced, so the content is set to 2.0 to 10.0%. More preferable upper and lower limits are, for the same reason as described above, the lower limit is more than 3.0% and the upper limit is 8.0%.
【0012】Si:2.0%以下 Siは溶解時の脱酸剤として添加されるが、これを多量
に添加すると靱性低下をきたすようになる。従って、S
i含有量の上限を2.0%に定める。好ましくは上限を
1.2%とする。 Mn:2.0%以下 Mnは溶解時の脱酸および脱硫剤として添加されるが、
多量に添加すると靱性が低下するのでその含有量の上限
を2.0%に定める。さらに好ましい上限は1.2%で
ある。
Si: 2.0% or less Si is added as a deoxidizing agent at the time of dissolution, but adding a large amount thereof causes a decrease in toughness. Therefore, S
The upper limit of the i content is set to 2.0%. Preferably, the upper limit is set to 1.2%. Mn: 2.0% or less Mn is added as a deoxidizing and desulfurizing agent during dissolution,
If added in a large amount, the toughness decreases, so the upper limit of the content is set to 2.0%. A more preferred upper limit is 1.2%.
【0013】Ni:4.0%以下 Niは鋼の焼入性を向上させて靱性を改善するのに有効
な元素であり、所望により含有させる。なお、上記作用
を確実に得るためには、0.1%以上含有させるのが望
ましい。しかし、4.0%を越えると変態点を下げて、
高温強度の低下をきたすのでその含有量を4.0%以下
に定める。さらに好ましい上限は1.5%である。
Ni: 4.0% or less Ni is an element effective for improving the hardenability of steel and improving the toughness, and may be contained if desired. In order to surely obtain the above-mentioned effects, it is desirable to contain 0.1% or more. However, when it exceeds 4.0%, the transformation point is lowered,
Since the high-temperature strength decreases, its content is set to 4.0% or less. A more preferred upper limit is 1.5%.
【0014】1/2W+Mo:6.0%以下 W、Moは焼戻し時に微細な特殊炭化物を形成し、引張
強さを高める作用を有するので、所望により1種または
2種を含有させる。この作用を確実に得るためには、上
記式の値が1.0%以上であるのが望ましい。しかし、
上記値が6.0%を越えると靱性の過度の低下を招くの
でその値が6.0%以下になるようにW、Moの含有量
を定める。さらに好ましい上限は3.5%である。
[0014] 1 / 2W + Mo: 6.0% or less W and Mo form fine special carbides during tempering and have an effect of increasing the tensile strength. Therefore, if necessary, one or two kinds of W and Mo are contained. In order to surely obtain this effect, it is desirable that the value of the above equation is 1.0% or more. But,
If the above value exceeds 6.0%, an excessive decrease in toughness is caused. Therefore, the contents of W and Mo are determined so that the value becomes 6.0% or less. A more preferred upper limit is 3.5%.
【0015】V:2.0%以下 Vは焼戻し時に炭窒化物を形成して、引張強度を高める
のに有効であるとともに結晶粒の微細化にも効果的であ
るので所望により含有させる。これら作用を確実に得る
ためには、0.4%以上含有させるのが望ましい。しか
し、2.0%を越えると靱性が低下するのでその含有量
を2.0%以下に定める。さらに好ましい上限は1.3
%以下である。
V: 2.0% or less V forms carbonitride at the time of tempering and is effective for increasing the tensile strength and also effective for refining the crystal grains, so that V is contained as desired. In order to surely obtain these effects, it is desirable to contain 0.4% or more. However, if the content exceeds 2.0%, the toughness decreases, so the content is set to 2.0% or less. A more preferred upper limit is 1.3.
% Or less.
【0016】Nb:0.20%以下 Nbは炭化物より固溶しにくい安定な炭化物を形成し、
結晶粒微細化にも効果的であるので所望により含有させ
る。なお、これら作用を確実に得るためには%以上含有
させるのが望ましい。しかし、0.20%を越えると逆
に粗大な炭窒化物を形成し、靱性を低下させるので、そ
の含有量を0.20%以下に定める。さらに好ましい上
限は0.07%以下である。上記各合金成分は、所望に
より含有させる選択成分として記載したが、これら成分
の全てを含有するものであってもよく、または一部成分
を含有しない組成であってもよい。
Nb: 0.20% or less Nb forms a stable carbide which is less soluble than carbide.
Since it is also effective in refining crystal grains, it is contained as desired. In order to surely obtain these effects, it is desirable that the content should be not less than%. However, when the content exceeds 0.20%, coarse carbonitrides are formed and the toughness is reduced. Therefore, the content is set to 0.20% or less. A more preferred upper limit is 0.07% or less. Although the above alloy components are described as optional components to be contained as desired, they may contain all of these components or may have a composition not containing some components.
【0017】上記中炭素鋼は、鍛錬に至るまでは常法、
または公知の工程を経たものであってよく、例えば、常
法により溶製した鋼塊を均質化処理等の熱処理を施した
後、適宜の鍛錬比で鍛錬する。該鍛錬後は、本発明の方
法により熱処理を施す。この熱処理によれば、結晶粒が
微細化するとともに、焼入後にはネット状炭化物の残存
しない組織が得られ、靱性、強度ともに優れた中炭素鋼
が得られる。また、該中炭素鋼の組成を本発明の範囲内
で定めれば、上記作用は確実なものとなり、従来材に比
べて顕著な靱性の改善効果が出現する。
[0017] The above-mentioned medium carbon steel is processed by a conventional method until it is forged.
Alternatively, the steel ingot may be subjected to a known process. For example, after performing a heat treatment such as a homogenization treatment on a steel ingot produced by a conventional method, the steel ingot is forged at an appropriate forging ratio. After the forging, heat treatment is performed by the method of the present invention. According to this heat treatment, the crystal grains are refined, a structure in which no net-like carbide remains after quenching is obtained, and a medium carbon steel excellent in both toughness and strength is obtained. Further, when the composition of the medium carbon steel is determined within the range of the present invention, the above-mentioned action is assured, and a remarkable effect of improving the toughness as compared with the conventional material appears.
【0018】[0018]
【実施例】表1に示す組成の供試鋼を取鍋精練法にて溶
解し、下注ぎ法にてllトン鋼塊を造塊した。これらの
鋼塊を1200℃に加熱して、鍛造比約6で熱間鍛造し
た後、表2に示す熱処理を施した。また、焼入れ、焼戻
しは各供試鋼で強度が同一になるように実施した。
EXAMPLE A test steel having the composition shown in Table 1 was melted by a ladle refining method, and an 11 ton steel ingot was formed by a downward pouring method. These ingots were heated to 1200 ° C. and hot forged at a forging ratio of about 6, and then heat-treated as shown in Table 2. In addition, quenching and tempering were performed such that the strength of each test steel was the same.
【0019】[0019]
【表1】 [Table 1]
【0020】[0020]
【表2】 [Table 2]
【0021】次に、熱処理後の供試鋼において結晶粒の
大きさの測定とシャルピー衝撃試験とを行い、その結果
を図1、2に示した。図1、2から明らかなように、本
発明法によれば、従来法に比べて、強度にかかわらず結
晶粒サイズが小さくなっており、シャルピー衝撃値が向
上している。図3には本発明法1と比較法4により得ら
れた供試鋼の金属組織の顕微鏡写真を示した。図3から
明らかなように、本発明法によれば、従来法に比べて、
結晶粒サイズが顕著に小さくなっており、ネット状炭化
物の残存も認められなかった。
Next, in the test steel after the heat treatment, the measurement of the crystal grain size and the Charpy impact test were performed, and the results are shown in FIGS. As is clear from FIGS. 1 and 2, according to the method of the present invention, as compared with the conventional method, the crystal grain size is reduced regardless of the strength, and the Charpy impact value is improved. FIG. 3 shows a micrograph of the metal structure of the test steel obtained by the method 1 of the present invention and the comparative method 4. As is clear from FIG. 3, according to the method of the present invention, compared with the conventional method,
The crystal grain size was significantly reduced, and no net-like carbide remained.
【0022】[0022]
【発明の効果】以上説明したように本願発明の中炭素鋼
の製造方法によれば、鍛錬からの冷却途中にパーライト
変態温度域で組織をパーライト変態させ、さらにAc
点以上の温度で1回以上の焼準処理を施した後、Ac
点以上の温度に加熱して焼入れし、その後、焼戻しを1
回以上施すので、ネット状炭化物の消失、結晶粒の微細
化によって靱性が大幅に向上する効果がある。従って、
上記の製造方法を所定組成の中炭素鋼に用いれば、上記
効果が顕著に得られ、靱性に優れた中炭素鋼が得られ
る。
As described above, according to the method for producing a medium carbon steel of the present invention, the structure is transformed into pearlite in the pearlite transformation temperature range during cooling from forging, and further, Ac 3
After performing one or more normalizing treatments at a temperature equal to or higher than the point, Ac 3
Quenching by heating to a temperature above the point, then tempering 1
Since the application is performed twice or more times, there is an effect that the toughness is greatly improved by the disappearance of the net-like carbides and the refinement of the crystal grains. Therefore,
If the above-mentioned manufacturing method is applied to a medium-carbon steel having a predetermined composition, the above-described effects are remarkably obtained, and a medium-carbon steel excellent in toughness is obtained.
【図面の簡単な説明】[Brief description of the drawings]
【図1】 実施例における各供試鋼の結晶粒サイズを比
較したグラフである。
FIG. 1 is a graph comparing the crystal grain size of each test steel in Examples.
【図2】 同じくシャルピー衝撃値を比較したグラフで
ある。
FIG. 2 is a graph comparing Charpy impact values.
【図3】 同じく金属組織の顕微鏡写真である。FIG. 3 is a micrograph of the same metal structure.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 小野 秀三 北海道室蘭市茶津町4番地 株式会社日本 製鋼所内 (72)発明者 田中 泰彦 北海道室蘭市茶津町4番地 株式会社日本 製鋼所内 (72)発明者 石黒 徹 東京都府中市日鋼町1番1 株式会社日本 製鋼所内 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shuzo Ono 4th Chazu-cho, Muroran, Hokkaido Japan Steel Works Co., Ltd. (72) Inventor Yasuhiko Tanaka 4th Chazu-cho, Muroran City, Hokkaido Japan Steel Works Co., Ltd. (72) Invention Toru Ishiguro 1-1 Nikko-cho, Fuchu-shi, Tokyo Inside the Japan Steel Works, Ltd.

Claims (3)

    【特許請求の範囲】[Claims]
  1. 【請求項1】 中炭素鋼を鍛錬からの冷却途中にパーラ
    イト変態温度域で組織をパーライト変態させ、さらにA
    点以上の温度で1回以上の焼準処理を施した後、A
    点以上の温度に加熱して焼入れし、その後、焼戻し
    を1回以上施すことを特徴とする中炭素鋼の製造方法
    1. The structure of a medium carbon steel is transformed into pearlite in a pearlite transformation temperature range during cooling from forging.
    c After performing one or more normalizing treatments at three or more temperatures,
    (c) a method for producing medium carbon steel, wherein the steel is heated to a temperature of three or more points, quenched, and then tempered at least once.
  2. 【請求項2】 中炭素鋼の組成が重量%で、C:0.2
    5〜0.55%、Cr:2.0〜10.0%を含有し、
    残部がFeおよび不可避的不純物からなることを特徴と
    する請求項1記載の中炭素鋼の製造方法
    2. The composition of a medium carbon steel in weight%, C: 0.2
    5 to 0.55%, Cr: 2.0 to 10.0%,
    2. The method according to claim 1, wherein the balance consists of Fe and inevitable impurities.
  3. 【請求項3】 中炭素鋼の組成が重量%で、C:0.2
    5〜0.55%、Cr:2.0〜10.0%、Si:
    2.0%以下、Mn:2.0%以下、Ni:4.0%以
    下、WおよびMoの単独又は複合で、(1/2W+M
    o):6.0%以下、V:2.0%以下、Nb:0.2
    0%以下を含有し、残部がFeおよび不可避的不純物か
    らなることを特徴とする請求項1記載の中炭素鋼の製造
    方法
    3. The composition of the medium carbon steel is expressed by weight% and C: 0.2
    5 to 0.55%, Cr: 2.0 to 10.0%, Si:
    2.0% or less, Mn: 2.0% or less, Ni: 4.0% or less, W or Mo alone or in combination, ((W + M
    o): 6.0% or less, V: 2.0% or less, Nb: 0.2
    2. The method for producing medium carbon steel according to claim 1, wherein the content is 0% or less, and the balance consists of Fe and unavoidable impurities.
JP00775699A 1999-01-14 1999-01-14 Manufacturing method of medium carbon steel Expired - Lifetime JP3544131B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP00775699A JP3544131B2 (en) 1999-01-14 1999-01-14 Manufacturing method of medium carbon steel

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP00775699A JP3544131B2 (en) 1999-01-14 1999-01-14 Manufacturing method of medium carbon steel

Publications (2)

Publication Number Publication Date
JP2000204414A true JP2000204414A (en) 2000-07-25
JP3544131B2 JP3544131B2 (en) 2004-07-21

Family

ID=11674551

Family Applications (1)

Application Number Title Priority Date Filing Date
JP00775699A Expired - Lifetime JP3544131B2 (en) 1999-01-14 1999-01-14 Manufacturing method of medium carbon steel

Country Status (1)

Country Link
JP (1) JP3544131B2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007016284A (en) * 2005-07-08 2007-01-25 Hitachi Metals Ltd Method for producing tool steel intermediate material, and method for producing tool steel
WO2007119721A1 (en) * 2006-04-11 2007-10-25 Hitachi Metals, Ltd. Method of pretreatment for quenching of martensitic tool steel and method of quenching
JP5093118B2 (en) * 2006-12-27 2012-12-05 日立金属株式会社 Tool steel manufacturing method
CN103898415A (en) * 2014-04-18 2014-07-02 北京科技大学 Improved Cr8 steel roll and preparation method thereof
WO2017220066A1 (en) 2016-06-24 2017-12-28 Schaeffler Technologies AG & Co. KG Camshaft adjuster

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101597681A (en) * 2009-07-09 2009-12-09 贵州大学 A kind of process for heat-treatment on spring steel product for high-speed heavy-load trains
CN104357643B (en) * 2014-11-06 2016-07-20 通裕重工股份有限公司 Net carbide Technology for Heating Processing is eliminated after a kind of roll forging
CN111647721A (en) * 2020-06-18 2020-09-11 建龙北满特殊钢有限责任公司 Method for solving low-temperature impact energy of high-alloy structural steel after hardening and tempering

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007016284A (en) * 2005-07-08 2007-01-25 Hitachi Metals Ltd Method for producing tool steel intermediate material, and method for producing tool steel
WO2007119721A1 (en) * 2006-04-11 2007-10-25 Hitachi Metals, Ltd. Method of pretreatment for quenching of martensitic tool steel and method of quenching
JP5288259B2 (en) * 2006-04-11 2013-09-11 日立金属株式会社 Pre-quenching method and quenching method for martensitic tool steel
JP5093118B2 (en) * 2006-12-27 2012-12-05 日立金属株式会社 Tool steel manufacturing method
CN103898415A (en) * 2014-04-18 2014-07-02 北京科技大学 Improved Cr8 steel roll and preparation method thereof
WO2017220066A1 (en) 2016-06-24 2017-12-28 Schaeffler Technologies AG & Co. KG Camshaft adjuster
DE102016211324A1 (en) 2016-06-24 2017-12-28 Schaeffler Technologies AG & Co. KG Phaser

Also Published As

Publication number Publication date
JP3544131B2 (en) 2004-07-21

Similar Documents

Publication Publication Date Title
JP2004143482A (en) High strength cold formed spring steel wire and its production method
US10851432B2 (en) Ultra-high strength and ultra-high toughness casing steel, oil casing, and manufacturing method thereof
JPH0967624A (en) Production of high strength oil well steel pipe excellent in sscc resistance
JPH06172859A (en) Production of high strength steel tube excellent in sulfide stress corrosion cracking resistance
CN108220774B (en) Wire rod and steel wire having excellent toughness, and method for producing same
JP4629816B2 (en) High strength bolt excellent in delayed fracture resistance and method for producing the same
JPH0892690A (en) Carburized parts excellent in fatigue resistance and its production
JP3901994B2 (en) Non-tempered high-strength and high-toughness forged product and its manufacturing method
JP3851147B2 (en) Non-tempered high strength and high toughness forged product and its manufacturing method
JP2000204414A (en) Production of medium carbon steel
JP2004124190A (en) Induction-tempered steel having excellent twisting property
JP4405026B2 (en) Method for producing high-tensile strength steel with fine grain
JP3858803B2 (en) Hot-rolled steel material and manufacturing method thereof
JP3228986B2 (en) Manufacturing method of high strength steel sheet
JP3246993B2 (en) Method of manufacturing thick steel plate with excellent low temperature toughness
JP6390685B2 (en) Non-tempered steel and method for producing the same
JP3458604B2 (en) Manufacturing method of induction hardened parts
JPH0756046B2 (en) Method for producing B-containing steel
JPH0813028A (en) Production of precipitation hardening steel material having high tensile strength and high toughness
JP3229107B2 (en) Manufacturing method of low yield ratio high strength steel sheet with excellent uniform elongation
JP3620099B2 (en) Method for producing Cr-Mo steel excellent in strength and toughness
JPH05339676A (en) Steel for machine structure excellent in cold workability and its manufacture
JP2000160285A (en) High-strength and high-toughness non-heat treated steel
JP2015183266A (en) Steel for high strength bolt excellent in delayed fracture resistance and high strength bolt
KR20190077842A (en) High phosphorus wire rod and formed material having excelent impact property and corrosion resistance, and method for manufacturing the same

Legal Events

Date Code Title Description
A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20040121

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20040330

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20040331

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090416

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100416

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100416

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110416

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110416

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120416

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130416

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20140416

Year of fee payment: 10

EXPY Cancellation because of completion of term