JPH06340946A - Non-tempered steel with high toughness and preparation thereof - Google Patents
Non-tempered steel with high toughness and preparation thereofInfo
- Publication number
- JPH06340946A JPH06340946A JP21622291A JP21622291A JPH06340946A JP H06340946 A JPH06340946 A JP H06340946A JP 21622291 A JP21622291 A JP 21622291A JP 21622291 A JP21622291 A JP 21622291A JP H06340946 A JPH06340946 A JP H06340946A
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- Prior art keywords
- steel
- heat treated
- toughness
- treated steel
- less
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
【０００１】[0001]
【産業上の技術分野】本発明は、調質処理を行わなかっ
た状態でも調質処理鋼と少なくとも同程度の機械的性質
を有する非調質鋼及びその製造方法に関するもので、詳
しくは、靭性及び引張強度が改良された高靭性非調質鋼
及びその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 non-heat treated steel having at least about the same mechanical properties as the heat treated steel even without heat treatment, and a method for producing the same. And a high toughness non-heat treated steel having improved tensile strength and a method for producing the same.
【０００２】[0002]
【従来の技術】一般に、非調質鋼とは、機械構造用鋼の
製造時、焼入れ及び焼戻し作業によって鋼の機械的性質
を改良する処理、すなわち調質処理を行わなくても、調
質処理された鋼のような機械的性質を有する鋼をいうの
であるが、これは、靭性が調質鋼と比べて非常に低いた
め、機械構成部品中、高い靭性が必要なく、高強度だけ
が要求される部品だけに使用が制限されるという問題が
あった。2. Description of the Related Art Generally, non-heat treated steel is a treatment for improving the mechanical properties of steel by quenching and tempering during the production of steel for machine structural use, that is, heat treatment without heat treatment. It is a steel that has mechanical properties similar to those of steels that have high mechanical strength.However, since it has much lower toughness than heat-treated steel, it does not require high toughness in mechanical components, and only high strength is required. There is a problem that the use is limited to only the parts that are used.
【０００３】近年、全世界では、エネルギー節約が叫ば
れているが、機械構造用鋼の製造においても、調質処理
で所要されるエネルギーを節減するために、非調質鋼の
拡大適用が求められている。このためには、非調質鋼の
欠点である靭性不足を効果的に改良しなければならな
い。従来の非調質鋼では、引張強度７５kgf/mm2以上の
高強度を得るために、Ｃを０．４５重量％（以下、略し
て％と表記する。）以上含有する組成の鋼を用いるか、
あるいはＣを０．０３ないし０．２５％、Ｃｒを１．５
ないし２．０％含有する組成の鋼を用いた。In recent years, energy saving has been sought all over the world, but also in the production of steel for machine structural use, in order to reduce the energy required for the heat treatment, the expanded application of non-heat treated steel is required. Has been. To this end, the shortage of toughness, which is a drawback of non-heat treated steel, must be effectively improved. In the conventional non-heat treated steel, is steel having a composition containing 0.45% by weight (abbreviated as%) of C or more in order to obtain high strength of 75 kgf / mm 2 or more in tensile strength? ,
Alternatively, C is 0.03 to 0.25%, Cr is 1.5
A steel having a composition containing 0.1 to 2.0% was used.
【０００４】しかし、この目的のために低炭素系非調質
鋼を用いる場合、耐摩耗性の向上のための高周波硬化を
行うことが困難であり、高強度を得るために別の冷却設
備が必要となる。また、Ｍｎを１．５５％以下添加して
組織の靭性を高める方法が提案されたが、これはＭｎの
増加に伴って素材の切削性が減少する問題があり、切削
性を向上させるためにＳ、Ｐｂ、Ｂｉなどの元素を多量
に添加することもあるが、これは素材の靭性を減少させ
る問題があり、また、これらの元素は鋼材料の熱間加工
時、容易に塑性変形させて組織内部に線形のＡタイプ介
在物状態で残る。However, when low carbon non-heat treated steel is used for this purpose, it is difficult to carry out high frequency hardening to improve wear resistance, and another cooling equipment is required to obtain high strength. Will be needed. Further, a method has been proposed in which Mn is added in an amount of 1.55% or less to enhance the toughness of the structure, but this has a problem that the machinability of the material decreases as the Mn increases. Although elements such as S, Pb, and Bi may be added in large amounts, this has the problem of reducing the toughness of the material, and these elements are easily plastically deformed during hot working of steel materials. It remains as a linear type A inclusion inside the tissue.
【０００５】さて、介在物は、その形状によって図５に
黒く示す線形のＡタイプと、多角形のＢタイプと、図４
に黒く示す球形のＣタイプに分かれる。上記線形のＡタ
イプ介在物は、方向性を有するために、鋼材料の靭性、
疲労強度などの機械的性質を弱め、例えば図５に示す素
材の衝撃値は、ＵＥ20で約３．９kgf・m/cm2と、図４に
示す球形のＣタイプ介在物状態の素材に比べて脆弱なの
で、その介在物自体の存在量とその形状とを制御すべき
である。By the way, the inclusions have a linear A type shown in black in FIG. 5 depending on their shapes, a polygonal B type, and FIG.
It is divided into the spherical C type shown in black. Since the linear A type inclusions have directionality, the toughness of the steel material,
The mechanical properties such as fatigue strength are weakened. For example, the impact value of the material shown in Fig. 5 is about 3.9 kgf · m / cm 2 for UE 20, which is more than that of the spherical C-type inclusion material shown in Fig. 4. Since it is fragile, the amount of the inclusion itself and its shape should be controlled.
【０００６】このような問題を解決するためにベイナイ
ト系非調質鋼が開発されたが、これは、製造時、急冷作
業が伴い、組織内のベイナイトが５０％以上の場合は、
素材の衝撃値が減少するので、その適用が制限され、ま
た、このような問題を解決するために、Ｃａと稀土類金
属を添加する方法が提案されたが、これは、添加する元
素の組成範囲が確かでないだけでなく、機械的性質の向
上のための具体的な方法を提示しなかった。[0006] In order to solve such a problem, a bainite type non-heat treated steel was developed. This is because when the manufacturing process involves quenching work and bainite in the structure is 50% or more,
Since the impact value of the material is reduced, its application is limited, and in order to solve such a problem, a method of adding Ca and a rare earth metal has been proposed. Not only is the range uncertain, but no specific method for improving the mechanical properties was presented.
【０００７】[0007]
【発明が解決しようとする課題】したがって、本発明の
目的は、前述したような従来技術の問題点を解決し、靭
性と引張強度を改良した高靭性非調質鋼及びその製造方
法を提供することにあるSUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a high toughness non-heat treated steel having improved toughness and tensile strength and a method for producing the same. Especially
【０００８】[0008]
【課題を解決するための手段】本発明の一特徴によれ
ば、重量％で、Ｃ；０．３０〜０．４５％、Ｓｉ；０．
１５〜０．３５％、Ｍｎ；１．０〜１．５５％、Ｓ；
０．０５０％以下、Ｃｒ；０．３０％以下、Ａｌ；０．
０１〜０．０５％、Ｖ、Ｎｂ、又はその混合物；０．０
５〜０．１５％、Ｔｉ；０．０〜０．０３％、Ｂ；０．
０００５〜０．００３％、Ｎ；０．２９２３Ｔｉ〜０．
０２％を包含し、残部はＦｅ及び製鋼工程で必ず含有さ
れる不純物から成る高靭性非調質鋼が提供される。According to one feature of the invention, in weight%, C; 0.30-0.45%, Si;
15-0.35%, Mn; 1.0-1.55%, S;
0.050% or less, Cr; 0.30% or less, Al;
01-0.05%, V, Nb, or a mixture thereof; 0.0
5 to 0.15%, Ti; 0.0 to 0.03%, B;
0005-0.003%, N; 0.2923Ti-0.
A high toughness non-heat treated steel is provided which comprises 02%, the balance being Fe and the impurities necessarily contained in the steel making process.
【０００９】本発明の二特徴によれば、重量％で、Ｃ；
０．３０〜０．５５％、Ｓｉ；０．１５〜０．４５％、
Ｍｎ；０．６０〜１．５５％、Ｓ；０．０５０％以下、
Ｃｒ；０〜０．３０％、Ａｌ；０．０１〜０．０５％、
Ｖ、Ｎｂ、又はその混合物；０．０５〜０．１５％、Ｔ
ｉ；０．０〜０．０３％、Ｎ；０．０２％以下を包含
し、残部はＦｅ及び製鋼工程で必ず含有される不純物か
ら成る高靭性非調質鋼が提供される。According to two features of the invention, in% by weight, C:
0.30 to 0.55%, Si; 0.15 to 0.45%,
Mn; 0.60 to 1.55%, S; 0.050% or less,
Cr; 0 to 0.30%, Al; 0.01 to 0.05%,
V, Nb, or a mixture thereof; 0.05 to 0.15%, T
There is provided a high toughness non-heat treated steel containing i: 0.0 to 0.03%, N: 0.02% or less, the balance being Fe and impurities necessarily contained in the steelmaking process.
【００１０】本発明の三特徴によれば、重量％で、Ｃ；
０．３０〜０．５５％、Ｓｉ；０．１５〜０．４５％、
Ｍｎ；０．６０〜１．５５％、Ｓ；０．０５０％以下、
Ｃｒ；０〜０．３０％、Ａｌ；０．０１〜０．０７５
％、Ｖ、Ｎｂ、又はその混合物；０．０５〜０．１５
％、Ｔｉ；０．０〜０．０３％、Ｂ；０〜０．００３
％、Ｎ；０．２９２３Ｔｉ〜０．０２％を含有する組成
物を通常の溶解炉及び溶解条件で処理してインゴットに
鋳造又は連続鋳造した後、それぞれの原料及び形状に応
じてＡｃ3以上ないし１３００℃以下の温度で熱間加工
した状態で一定の厚さに圧延する段階と、８００〜９５
０℃から５００〜５５０℃まで１０〜１５０℃/minの冷
却速度で冷却する段階から成る高靭性非調質鋼の製造方
法が提供される。According to three features of the invention, in% by weight, C:
0.30 to 0.55%, Si; 0.15 to 0.45%,
Mn; 0.60 to 1.55%, S; 0.050% or less,
Cr; 0 to 0.30%, Al; 0.01 to 0.075
%, V, Nb, or a mixture thereof; 0.05 to 0.15
%, Ti; 0.0 to 0.03%, B; 0 to 0.003
%, N; 0.2923 Ti to 0.02% is treated in a normal melting furnace and melting conditions and cast into an ingot or continuous casting, and then Ac 3 or more depending on each raw material and shape. Rolling to a constant thickness in a state of hot working at a temperature of 1300 ° C. or lower, and 800 to 95
Provided is a method for producing a high toughness non-heat treated steel, which comprises a step of cooling from 0 ° C to 500 to 550 ° C at a cooling rate of 10 to 150 ° C / min.
【００１１】本発明によって、高靭性、高強度、及び高
周波硬化能を得るために、上記成分から成った非調質鋼
を上記のように特定の温度条件で制御しなければならな
い。本発明によって製造される非調質鋼は、ＶとＮｂと
でＡ3変態後析出強化によって硬度を増大させ、炭、窒
化物の析出によって、加熱時オーステナイト結晶粒の成
長を抑制して結晶粒微細化効果で靭性を増大させた非調
質鋼である。According to the present invention, in order to obtain high toughness, high strength and high frequency hardening ability, the non-heat treated steel composed of the above components must be controlled under the specific temperature conditions as described above. The non-heat treated steel produced according to the present invention increases the hardness by precipitation strengthening after A 3 transformation with V and Nb, and the precipitation of carbon and nitride suppresses the growth of austenite crystal grains during heating to suppress the crystal grain. A non-heat treated steel with increased toughness due to the effect of refinement.
【００１２】上記鋼中の成分を限定した理由は次の通り
である。Ｃは、強度と硬度を得るための必須の成分とし
て、Ｂを含有する場合は、少なくとも０．３０％（場合
によっては０．３５％）が含有されなければ引張強度７
５kgf/mm2以上を得ることができないが、０．４５％を
超えると、Ｂ効果（ｂｏｒｏｎ ｅｆｆｅｃｔ）が急激
に下がって強度と靭性が低減する。これは、Ｂが鋼内の
フェライト形成を助けて靭性を向上させ、ほう素炭化物
は析出強化効果によって強度を向上させるが、炭素量の
増加に反比例してＢ効果がしだいに減少するためであ
る。また、Ｂを含有しない場合は、Ｃが０．５５％を超
えると、構造用鋼として使用できない状態まで靭性と溶
接性が低減する。The reasons for limiting the components in the above steel are as follows. C is an essential component for obtaining strength and hardness, and when B is contained, at least 0.30% (in some cases, 0.35%), the tensile strength is 7 if not contained.
Although it is not possible to obtain 5 kgf / mm 2 or more, if it exceeds 0.45%, the B effect (boron effect) is drastically lowered and the strength and toughness are reduced. This is because B assists the formation of ferrite in the steel to improve the toughness, and the boron carbide improves the strength by the precipitation strengthening effect, but the B effect gradually decreases in inverse proportion to the increase in the carbon content. . Further, in the case where B is not contained, if C exceeds 0.55%, the toughness and weldability are reduced to a state where it cannot be used as structural steel.
【００１３】Ｓｉは、製鋼中脱酸剤として作用し、フェ
ライト強化効果があるが、０．４５％（場合によっては
０．３５％）を超えると、初析フェライト変態を促進さ
せて靭性が低減するので制限した。Ｍｎは、強度と靭性
を向上させる安価な合金元素で、製鋼中脱硫剤として大
切な元素であり、特に本発明ではＭｎＳを用いて靭性を
向上させるので必須の元素である。上記非調質鋼の場
合、炭素量が少ないため、もっと高い強度向上効果が必
要で、Ｍｎは少なくとも０．６０％（場合によっては
１．０％）以上を添加するべきであり、また、１．５５
％以上を添加すると、切削性と溶接性とが低減するので
制限した。Si acts as a deoxidizer during steelmaking and has a ferrite strengthening effect, but if it exceeds 0.45% (in some cases 0.35%), proeutectoid ferrite transformation is promoted and toughness is reduced. Because it does, it was limited. Mn is an inexpensive alloying element that improves strength and toughness, and is an important element as a desulfurizing agent during steelmaking. In particular, MnS is an essential element in the present invention because it improves toughness. In the case of the above-mentioned non-heat treated steel, since the carbon content is small, a higher strength improving effect is required, and Mn should be added at least 0.60% (1.0% in some cases) or more. .55
%, The machinability and weldability are reduced, so the content is limited.
【００１４】Ｓは、製鋼中必ず含有されて塑性変形温度
の低い硫化物を形成するので、従来の鋼においては、
０．０２５％以下が通常であるが、本発明においては、
切削性向上だけでなく、パーライト粒内フェライト形成
効果があって非調質鋼の欠点である靭性不足を補うの
で、最大０．０５０％以下が望ましく、０．０５０％を
超えると靭性と強度を減少させるので制限した。S is always contained in steel making and forms sulfides having a low plastic deformation temperature.
Although it is usually 0.025% or less, in the present invention,
In addition to improving machinability, it also has the effect of forming pearlite intragranular ferrite to compensate for the lack of toughness, which is a drawback of non-heat treated steel. I limit it because it decreases.
【００１５】Ｃｒは、フェライト内に固溶されて効果的
に強化させるので、低炭素鋼である場合、少量添加する
ことは望ましいが、０．３％以上は靭性を低減させるの
で制御した。Ａｌは、脱酸作用が強いので製鋼中使用
し、分散化合物と窒化物の効果により鋼中に残って結晶
粒を微細化させ、靭性を向上させるが、０．０１％以下
では十分に脱酸されず、また０．０７５％以上（場合に
よっては０．０５％以上）では、ＳｉＯ2に少量含有さ
れて容易に塑性変形され、切削性と清浄性を下げるので
制限した。Since Cr is solid-solved in ferrite and effectively strengthens it, it is desirable to add a small amount in the case of low carbon steel, but 0.3% or more reduces the toughness, so it was controlled. Since Al has a strong deoxidizing effect, it is used in steelmaking, and remains in the steel due to the effect of the dispersion compound and the nitride to refine the crystal grains and improve the toughness, but if 0.01% or less is sufficiently deoxidized. If it is not contained, and if it is 0.075% or more (0.05% or more in some cases), it is contained in a small amount in SiO 2 and is easily plastically deformed to lower the machinability and cleanability.
【００１６】Ｖは、炭化物と窒化物とを形成して強度と
靭性を向上させ、少量でも効果的に強度を向上させるこ
とができるので添加する。Ｎｂは、熱間加工中、オース
テナイトの再結晶を抑えて結晶の微細化を助けるので、
変態後微細に析出されて強度を向上させる。したがっ
て、ＶとＮｂとは、ともに強度と靭性を向上させるが、
過度な添加は溶接性を下げるので、０．１５％以下に制
限したが、場合によって、０．０５％以下では強度と靭
性不足のような悪い結果が生じることもある。V is added because it forms carbides and nitrides to improve strength and toughness, and even a small amount can effectively improve strength. Since Nb suppresses recrystallization of austenite during hot working and helps refine the crystal,
After transformation, it is finely precipitated to improve the strength. Therefore, both V and Nb improve strength and toughness,
Excessive addition lowers the weldability, so it was limited to 0.15% or less, but depending on the case, if it is 0.05% or less, bad results such as insufficient strength and toughness may occur.
【００１７】Ｂは、上記非調質鋼にフェライト形成促進
及び硬化能向上効果を提供するように作用する元素とし
て、０．０００５％以上添加するが、０．００３％以上
はむしろ靭性を低減させるので制限した。Ｔｉは、Ｎと
の結合力が強く、その大部分が窒化物を形成し、特にオ
ーステナイト粒度を微細にするので靭性向上効果が高い
が、０．０３％以上は上記効果がなく、場合によって、
０．０１％以下は強度を低減させることもある。B is an element that acts to provide the effects of promoting ferrite formation and improving hardenability to the non-heat treated steel, and is added in an amount of 0.0005% or more, but 0.003% or more rather reduces toughness. Because it was limited. Ti has a strong bonding force with N, and most of them form a nitride, and particularly the austenite grain size is made fine, so that the toughness improving effect is high, but 0.03% or more does not have the above effect, and depending on the case,
If it is 0.01% or less, the strength may be reduced.
【００１８】Ｃａ、Ｔｅ、Ｃｅ及びその他の稀土類金
属、ミッシュメタル、とこれらの混合物などのような金
属元素は、介在物形状、特にＭｎＳの形状を調節して、
熱間加工後、材質異方性と衝撃靭性とを改良するので、
必要によって添加することができ、０．０００１％以上
は望ましいが、０．０４％以上は効果の増大がないので
制限した。Metal elements such as Ca, Te, Ce and other rare earth metals, misch metals, mixtures thereof and the like adjust the shape of inclusions, especially the shape of MnS,
After hot working, it improves the material anisotropy and impact toughness, so
It can be added if necessary. 0.0001% or more is desirable, but 0.04% or more is limited because it does not increase the effect.
【００１９】Ｃは、ＶとともにＶ4Ｃ3あるいはＶ8Ｃ7の
ような炭化物を形成し、Ｎｂとは、ＮｂＣあるいはＮｂ
（ＣＮ）のような形態として存し、Ｔｉとは、ＴｉＣあ
るいはＴｉ（ＣＮ）として存し、極少量がＢとともにＦ
ｅ3（Ｃ、Ｂ）として存する。 Ｎは、ＴｉとともにＴ
ｉＮあるいはＴｉ（ＣＮ）を形成し、Ａｌとは、ＡｌＮ
を形成し、Ｖとは、ＶＮ、Ｖ（ＣＮ）を形成し、極少量
がＢＮを形成する。しかし、添加の次第によって、Ｎの
大部分はＢＮとして結合する場合があるので、ＢＮの形
成を抑えるために、Ｂは最後に添加することが通常であ
る。C forms a carbide such as V 4 C 3 or V 8 C 7 with V, and Nb means NbC or Nb.
(CN) -like form, Ti exists as TiC or Ti (CN), and a very small amount of B and F
It exists as e 3 (C, B). N is T together with Ti
iN or Ti (CN) is formed, and Al is AlN
And V forms VN and V (CN), and a very small amount forms BN. However, depending on the addition, most of N may be bonded as BN, so that B is usually added last in order to suppress the formation of BN.
【００２０】この炭、窒化物は、生成温度が高く、再結
晶温度の上昇と結晶粒の微細化を助け、微細な炭化物は
フェライト素地を効果的に強化させる。ＴｉＮは、生成
温度が最も高く、１４５０℃〜１１００℃で析出して、
オーステナイト結晶の核生成位置として作用する。上記
温度より低い温度でＴｉ（ＣＮ）などが形成され、９５
０℃〜８００℃でＮｂＶが析出し、９００℃〜７５０℃
でＶＮが析出し、それより低い温度でＶＣが析出する。
Ａｌは、ＮとともにＡｌＮを形成する。その量があまり
に少ないので、十分な効果を得ることができないが、一
度形成するとＴｉＮのような生成温度を有するので効果
がある。さて、この炭、窒化物は、ＭｎがＣとＮの活性
度を低減させるので、効果を得るためには必ずＣとＮの
活性度を高めるＶ、Ｎｂのような元素が必要である。こ
の場合、ＶはＮｂより小さい侵入形で容易に拡散、分散
されるので効果的である。These carbons and nitrides have a high formation temperature and help to raise the recrystallization temperature and refine the crystal grains, and the fine carbides effectively strengthen the ferrite matrix. TiN has the highest production temperature and precipitates at 1450 ° C to 1100 ° C.
It acts as a nucleation site for austenite crystals. Ti (CN) and the like are formed at a temperature lower than the above temperature.
NbV precipitates at 0 ° C to 800 ° C, 900 ° C to 750 ° C
At that temperature, VN is deposited, and at a lower temperature, VC is deposited.
Al forms AlN with N. Since the amount is too small, a sufficient effect cannot be obtained, but once formed, it has an effect because it has a generation temperature like TiN. In this carbon and nitride, Mn reduces the activities of C and N, so that elements such as V and Nb which increase the activities of C and N are necessary to obtain the effect. In this case, V is effective because it is easily diffused and dispersed in an interstitial form smaller than Nb.
【００２１】本発明の他の特徴は、上記炭、窒化物がオ
ーステナイト結晶の核生成位置として作用することだけ
でなく、靭性を効果的に向上させるために粒内フェライ
トの生成を促進するためのＭｎＳを用いることである。
また、通常の鋼と異なり、多少過量のＳを添加すること
により、ＭｎＳが粒内フェライトの核生成位置として作
用し、このＭｎＳが靭性を低減する欠点を極小化するた
めに、Ｃａ、Ｔｅ、Ｃｅ又はその他の稀土類金属、又は
ミッシュメタルで形状を制御する。Another feature of the present invention is that not only the above-mentioned carbon and nitride act as nucleation positions of austenite crystals, but also to promote generation of intragranular ferrite in order to effectively improve toughness. The use of MnS.
In addition, unlike ordinary steel, by adding a slight excess of S, MnS acts as a nucleation position of intragranular ferrite, and this MnS minimizes the drawback of reducing toughness, so that Ca, Te, The shape is controlled by Ce or other rare earth metal or misch metal.
【００２２】本発明によれば、上記の介在物形状制御元
素を０．０００１ないし０．０４％添加するので、上記
介在物に関して更に詳しく説明する。まず、転炉、電気
炉又は真空溶解炉などを用いる製鋼過程で生成される介
在物は、その生成要因を内的又は外的要因に分けること
ができる。内的要因による介在物は、主として脱酸作用
によるＳｉＯ2、ＭｎＯなどの脱酸生成物、ＭｎＳなど
の硫化物、窒化物又はこれらの複合化物などであり、外
的要因による介在物は、溶融状態の鋼が炉壁などを構成
している耐火物と反応して生成される硅酸質耐火物で、
その形状が線形であるＡタイプ、多角形であるＢタイ
プ、球形であるＣタイプに分かれる。According to the present invention, 0.0001 to 0.04% of the inclusion shape controlling element is added, so that the inclusion will be described in more detail. First, the inclusions generated in a steelmaking process using a converter, an electric furnace, a vacuum melting furnace, or the like can be divided into internal or external factors. Inclusions due to internal factors are mainly deoxidation products such as SiO 2 and MnO due to deoxidation action, sulfides such as MnS, nitrides or their composites, and inclusions due to external factors are melted. The silicate-based refractory that is produced by reacting the steel in the state with the refractory that constitutes the furnace wall, etc.
The shape is linear A type, polygonal B type, and spherical C type.
【００２３】すなわち、脱酸処理したキルド鋼中のＳｉ
−Ｍｎ系キルド鋼で生成される酸化物系介在物は、Ｓｉ
Ｏ2、ＭｎＯ、Ｍｎ−シリケートなどであり、Ａｌ系キ
ルド鋼は、主としてＡｌ2Ｏ3系の介在物であり、上記の
ような介在物は、凝固初期にその形状が球形又は六方晶
として存するが、Ａｌ、Ｔｉ、Ｃｒなどのような元素の
酸化物は、融点が高いので互いに集積された形状で分布
される。ところで、融点の低い酸化物と硫化物は、熱間
圧延又は鍛造作業のような熱間加工作業時に容易に塑性
変形して線形に長くなるので、この介在物と素地組織と
の物性の差異によって、素材の靭性を低減させるか又は
切削性を低減させる問題がある。That is, Si in the deoxidized killed steel
The oxide-based inclusions produced in -Mn-based killed steel are Si
O 2 , MnO, Mn-silicate, etc., Al-based killed steel is mainly Al 2 O 3 -based inclusions, and the above-mentioned inclusions exist as spherical or hexagonal crystals in the initial stage of solidification. However, since oxides of elements such as Al, Ti, and Cr have high melting points, they are distributed in an integrated form. By the way, since oxides and sulfides having a low melting point are easily plastically deformed and linearly lengthened during hot working such as hot rolling or forging, the difference in physical properties between the inclusions and the base structure causes However, there is a problem that the toughness of the material is reduced or the machinability is reduced.
【００２４】したがって、本発明では、Ａｌを用いて脱
酸作業を行うが、このとき生成される脱酸生成物である
アルミナ（Ａｌ2Ｏ3）は、比較的小さくて硬度が高いの
で、熱間加工する場合でも塑性変形によって容易に線形
に変形されない。一方、上記介在物中の多量を占めてい
る硫化物の大部分はＭｎＳであるが、もし、Ａｌ、Ｔ
ｉ、Ｃｒなどのような元素が存すれば、Ａｌ2Ｓ、Ｃ
3Ｓ、ＣｒＳ、ＴｉＳなどのような極少量の硫化物が形
成される場合もある。Therefore, in the present invention, deoxidation work is carried out using Al. The alumina (Al 2 O 3 ) which is the deoxidation product produced at this time is relatively small and has a high hardness. Even during hot working, it is not easily linearly deformed by plastic deformation. On the other hand, most of the sulfides occupying a large amount in the above inclusions are MnS, but if Al, T
If there are elements such as i, Cr, etc., Al 2 S, C
Very small amounts of sulphides such as 3 S, CrS, TiS etc. may be formed.
【００２５】以下、上記のような化学組成を有する合金
鋼であり、介在物の形状が制御された本発明の非調質鋼
の製造方法を説明する。まず、上記の化学組成を有する
合金鋼を転炉、電気炉又は真空溶解炉などによって所定
温度で溶解させる。電気炉によって製鋼する場合は、通
常、Ｓ、Ｐなどの不純物が混入される心配はないが、空
気中のＯ2、Ｎ2などの混入量が増大するので、Ａｌのよ
うな適した脱酸剤を用いるか、あるいは真空溶解などの
方法を用いてガスを取り除くべきである。The method for producing the non-heat treated steel of the present invention, which is an alloy steel having the above chemical composition and in which the shape of inclusions is controlled, will be described below. First, alloy steel having the above chemical composition is melted at a predetermined temperature in a converter, an electric furnace, a vacuum melting furnace, or the like. When steelmaking is performed by an electric furnace, there is usually no concern that impurities such as S and P will be mixed, but since the amount of O 2 and N 2 and the like mixed in the air will increase, suitable deoxidation such as Al The agent should be used or the gas should be removed using a method such as vacuum melting.
【００２６】すなわち、本発明で用いたＡｌ脱酸方法に
よって脱酸した後得られた生成物中のＡｌ2Ｏ3、Ｓｉ０
2などの酸化物系介在物は、大きさが小さくて硬度が高
いので、少量の場合は鋼の機械的性質に及ぼす影響が比
較的小さくて問題にならないが、上記硫化物系介在物
は、大きさが大きくて線形などの不規則形状を有するの
で、本発明の介在物形状制御は、主として硫化物系介在
物の形状制御について行った。このために、本発明で
は、上記したように介在物形状制御元素を０．０００１
ないし０．０４重量％添加して脱酸作用を行うとともに
硫化物の形状を制御する作用を行うが、このとき、Ｓ
ｉ、Ｍｎ、Ａｌなどの元素で脱酸作業をした後、上記Ｃ
ａを添加すると介在物の形状制御効果が増大される。That is, Al 2 O 3 and SiO in the product obtained after deoxidizing by the Al deoxidizing method used in the present invention
Since oxide inclusions such as 2 have a small size and high hardness, the effect on the mechanical properties of steel is relatively small when a small amount is present, which is not a problem, but the above sulfide inclusions are Since the size is large and it has an irregular shape such as a linear shape, the inclusion shape control of the present invention was performed mainly for the shape control of the sulfide inclusions. Therefore, in the present invention, the inclusion shape control element is added to 0.0001 as described above.
Add 0.04 to 0.04% by weight to perform deoxidizing action and control the shape of sulfide.
After deoxidizing with elements such as i, Mn and Al, the above C
When a is added, the effect of controlling the shape of inclusions is increased.
【００２７】すなわち、上記介在物形状制御元素は、脱
酸作業の生成物であるＡｌ2Ｏ3のような高融点酸化物と
結合した状態の酸化物を外から囲む形状に硫化物を形成
させて全体的に球形の介在物を形成させるが、このよう
な球形介在物は熱間加工によっても容易に塑性変形され
ないので、図４に黒く示すようにほとんど球形のＣタイ
プとして存し、このとき衝撃値はＵＥ20で約８．６kgf・
m/cm2になって鋼の靭性を大幅に向上させる。That is, the inclusion shape control element forms a sulfide in a shape that surrounds an oxide in a state of being bound to a refractory oxide such as Al 2 O 3 which is a product of deoxidation work from the outside. Form spherical inclusions as a whole, but since such spherical inclusions are not easily plastically deformed by hot working, they exist as almost spherical C type as shown in black in FIG. Impact value is about 8.6 kgf for UE 20
M / cm 2 greatly improves the toughness of steel.
【００２８】一方、本発明は、上記介在物形状制御元素
を添加して介在物の形状制御によって靭性を増大させる
とともに各合金元素によって機械的性質を改良させる
が、すなわち上記のように製鋼された合金鋼を熱間加工
すると、１３００℃以上の温度でＡｌＮ又はＴｉＮが析
出されてオーステナイト粒子の生成核として作用し、１
０００℃以下の温度で圧延又は鍛造作業すると、Ｎｂ
Ｃ、ＶＮ、ＶＣＮなどの化合物が次第に析出する。ま
た、上記ＮｂＣ、ＶＮは，オーステナイト粒子の粗大化
を抑えて微細化を促すとともに、再結晶温度の低下を防
ぐ。On the other hand, according to the present invention, the inclusion shape controlling element is added to increase the toughness by controlling the shape of the inclusion and improve the mechanical properties by each alloying element, that is, the steel is manufactured as described above. When hot working the alloy steel, AlN or TiN is precipitated at a temperature of 1300 ° C. or higher and acts as a nucleus for forming austenite particles.
When rolling or forging work at a temperature below 000 ° C, Nb
Compounds such as C, VN and VCN gradually precipitate. Further, the NbC and VN suppress coarsening of the austenite particles to promote fineness, and prevent lowering of the recrystallization temperature.
【００２９】上記の加工中に成長するオーステナイト粒
子は、通常、丸い粒子のような多角形の形状を有し、Ａ
ｒ3変態線に相当する温度以下に冷却されることによっ
て、ＶＣＮが粒界で析出して粒界析出強化効果を得ると
ともに、上記冷却過程で変態して析出されたフェライト
は、加工硬化によって強度が増大され、Ａｒ1変態線に
相当する温度以下に冷却されると、パーライトを構成し
ているフェライトも鍛造作業による加工硬化現象によっ
て強化されるので、鋼の疲労強度などのような剛性が向
上される。The austenite grains that grow during the above processing usually have a polygonal shape, such as round grains.
By cooling below the temperature corresponding to the r 3 transformation line, VCN precipitates at the grain boundaries to obtain a grain boundary precipitation strengthening effect, and at the same time, the ferrite transformed and precipitated during the above cooling process is strengthened by work hardening. When the temperature is increased and cooled to a temperature equal to or lower than the Ar 1 transformation line, the ferrite that constitutes pearlite is also strengthened by the work hardening phenomenon due to the forging work, so the rigidity such as the fatigue strength of steel is improved. To be done.
【００３０】上述したように、本発明は、所定の化学組
成を有する合金鋼に、Ｃａ、Ｔｅ、Ｃｅ及びその他の稀
土類金属を単独又は複合的に添加するか、あるいはミッ
シュメタルのような介在物形状制御元素を所定量添加し
て、Ａｌ脱酸作業の生成物であるＡｌ2０3を、ＭｎＳな
どの硫化物が囲むようにして介在物の形状を球形に形成
することによって鋼の靭性が低減されるのを防ぎ、Ｎ
ｂ、Ｖ、Ｎなどの合金元素が粒子の微細化を促進すると
ともに析出強化作用をして熱間加工中の再結晶温度の低
下を防ぐことによるフェライトの加工強化効果によって
鋼の剛性を大幅に向上させるので、調質処理をしなくて
も調質鋼に対等な機械的性質を有する優れた非調質鋼を
得ることができるとともに、非調質鋼の製造工程を効率
化することができる効果がある。したがって、高靭性非
調質鋼の製造時、低炭素、高合金が要る欠点を克服でき
る。As described above, according to the present invention, Ca, Te, Ce and other rare earth metals are added singly or in combination to the alloy steel having a predetermined chemical composition, or an intermediate such as misch metal is added. The toughness of steel is reduced by adding a certain amount of a physical shape control element and forming a spherical shape of inclusions by surrounding Al 2 O 3 which is a product of Al deoxidation work with sulfides such as MnS. To prevent being
Alloying elements such as b, V, and N promote grain refinement and at the same time, strengthen precipitation by strengthening the precipitation strengthening effect and preventing the decrease in recrystallization temperature during hot working. Since it improves, it is possible to obtain an excellent non-heat treated steel having mechanical properties equivalent to that of the heat treated steel without performing heat treatment, and also to improve the efficiency of the manufacturing process of the non-heat treated steel. effective. Therefore, when manufacturing high toughness non-heat treated steel, the drawbacks of low carbon and high alloy can be overcome.
【００３１】[0031]
【実施例】以下、本発明の鋼及びその製造方法を実施例
に基づいて説明するが、本発明はこれらの実施例に限ら
れるものではない。後記の表１に示すような成分組成を
用いて実験室溶解炉で溶解し、１００mm×１００mmの四
角形インゴットに鋳造した後、１３００〜９２０℃で制
御鍛造してφ５０mmに圧延した。この鋼を９２０℃から
５２０℃まで６０℃/minの冷却速度で冷却した後、通常
の引張試験と衝撃靭性試験を実施して、その結果を後記
の表２に示した。EXAMPLES The steel of the present invention and the method for producing the same will be described below based on examples, but the present invention is not limited to these examples. After melted in a laboratory melting furnace using the composition shown in Table 1 below, cast into a 100 mm × 100 mm square ingot, controlled forging was performed at 1300 to 920 ° C., and rolled to φ50 mm. After cooling this steel from 920 ° C. to 520 ° C. at a cooling rate of 60 ° C./min, ordinary tensile tests and impact toughness tests were carried out, and the results are shown in Table 2 below.
【００３２】[0032]
【表１】 [Table 1]
【００３３】[0033]
【表２】 [Table 2]
【００３４】[0034]
【発明の効果】以上説明したように、本発明によれば、
非調質鋼でも調質処理鋼と同程度の高い靭性値を得るこ
とができるとともに、調質処理の省略によってコストと
人力を低減できるので、従来の調質鋼又は非調質鋼より
生産原価面と適用面で優れる。また、添付図面を見る
と、本発明の鋼は、組織が微細で靭性が高いことがわか
る。As described above, according to the present invention,
Non-heat treated steel can obtain the same high toughness value as heat treated steel, and the cost and manpower can be reduced by omitting the heat treatment, so the production cost is higher than that of conventional heat treated or non-heat treated steel. Excellent in terms of application and application. Further, from the attached drawings, it is understood that the steel of the present invention has a fine structure and high toughness.
【図１】本発明の一実施例による高靭性非調質鋼の光学
顕微鏡写真（×４００）。FIG. 1 is an optical micrograph (× 400) of a high toughness non-heat treated steel according to an embodiment of the present invention.
【図２】本発明の一実施例による高靭性非調質鋼のＳＥ
Ｍ（走査型電子顕微鏡）写真（×５５０）。FIG. 2 SE of high toughness non-heat treated steel according to one embodiment of the present invention
M (scanning electron microscope) photograph (× 550).
【図３】本発明の他の実施例による高靭性非調質鋼の光
学顕微鏡写真（×４００）。FIG. 3 is an optical micrograph (× 400) of a high toughness non-heat treated steel according to another embodiment of the present invention.
【図４】本発明による高靭性非調質鋼における介在物の
形状を示す光学顕微鏡写真（×４００）。FIG. 4 is an optical micrograph (× 400) showing the shape of inclusions in the high toughness non-heat treated steel according to the present invention.
【図５】従来技術による高靭性非調質鋼における介在物
の形状を示す光学顕微鏡写真（×４００）。FIG. 5 is an optical micrograph (× 400) showing the shape of inclusions in a high-toughness non-heat treated steel according to the prior art.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 チャング ウォーク ウィ 大韓民国、キュングサングナムドウ、チャ ングウォン市、ミュングセオドン、151− ５ (72)発明者 イン スク ユ 大韓民国、キュングサングナムドウ、チャ ングウォン市、バンリムドン、ヒュンダイ アパートメント、206−1405 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Chang Walk We, Republic of Korea, Kungsungnam Doo, Changwon City, Mungseodong, 151-5 (72) Inventor Insukuyu Republic of Korea, Kungsung Nam Doo, Changwon City, Banrim Dong, Hyundai Apartment, 206-1405
Claims (5)
Ｓｉ；０．１５〜０．３５％、Ｍｎ；１．０〜１．５５
％、Ｓ；０．０５０％以下、Ｃｒ；０．３０％以下、Ａ
ｌ；０．０１〜０．０５％、Ｖ、Ｎｂ、又はその混合
物；０．０５〜０．１５％、Ｔｉ；０．０〜０．０３
％、Ｂ；０．０００５〜０．００３％、Ｎ；０．２９２
３Ｔｉ〜０．０２％を包含し、残部はＦｅ及び製鋼工程
で必ず含有される不純物から成って、７５kgf/mm2以上
の引張強度と７kgmf/cm2以上の靭性を有することを特徴
とする高靭性非調質鋼。1. C, 0.30 to 0.45% by weight,
Si; 0.15 to 0.35%, Mn; 1.0 to 1.55
%, S; 0.050% or less, Cr; 0.30% or less, A
1; 0.01 to 0.05%, V, Nb, or a mixture thereof; 0.05 to 0.15%, Ti; 0.0 to 0.03
%, B; 0.0005 to 0.003%, N; 0.292
3Ti-0.02%, the balance consisting of Fe and impurities necessarily contained in the steelmaking process, having a tensile strength of 75 kgf / mm 2 or more and a toughness of 7 kgmf / cm 2 or more. Tough non-heat treated steel.
Ｓｉ；０．１５〜０．４５％、Ｍｎ；０．６０〜１．５
５％、Ｓ；０．０５０％以下、Ｃｒ；０〜０．３０％、
Ａｌ；０．０１〜０．０５％、Ｖ、Ｎｂ、又はその混合
物；０．０５〜０．１５％、Ｔｉ；０．０〜０．０３
％、Ｎ；０．０２％以下を包含し、残部はＦｅ及び製鋼
工程で必ず含有される不純物から成って、７５kgf/mm2
以上の引張強度と７kgmf/cm2以上の靭性を有することを
特徴とする高靭性非調質鋼。2. C, 0.30 to 0.55% by weight,
Si; 0.15 to 0.45%, Mn; 0.60 to 1.5
5%, S; 0.050% or less, Cr; 0 to 0.30%,
Al: 0.01-0.05%, V, Nb, or a mixture thereof; 0.05-0.15%, Ti: 0.0-0.03
%, N; 0.02% or less, the balance consisting of Fe and impurities necessarily contained in the steelmaking process, 75 kgf / mm 2
A high toughness non-heat treated steel characterized by having the above tensile strength and a toughness of 7 kgmf / cm 2 or more.
属、ミッシュメタル、及びその混合物から成るグループ
より選ばれた元素が０．０００１〜０．０４重量％含有
されることを特徴とする請求項２記載の高靭性非調質
鋼。3. An element selected from the group consisting of Ca, Te, Ce and other rare earth metals, misch metals, and mixtures thereof is contained in an amount of 0.0001 to 0.04% by weight. A high toughness non-heat treated steel according to item 2.
Ｓｉ；０．１５〜０．４５％、Ｍｎ；０．６０〜１．５
５％、Ｓ；０．０５０％以下、Ｃｒ；０〜０．３０％、
Ａｌ；０．０１〜０．０７５％、Ｖ、Ｎｂ、又はその混
合物；０．０５〜０．１５％、Ｔｉ；０．０〜０．０３
％、Ｂ；０〜０．００３％、Ｎ；０．２９２３Ｔｉ〜
０．０２％を含有する組成物を通常の溶解炉及び溶解条
件で処理して連鋳又はインゴットに鋳造した後、それぞ
れの原料及び形状に応じてＡｃ3以上ないし１３００℃
以下の温度で熱間加工した状態で一定の厚さに圧延する
段階と、８００〜９５０℃から５００〜５５０℃まで１
０〜１５０℃/minの冷却速度で冷却する段階から成るこ
とを特徴とする高靭性非調質鋼の製造方法。4. C, 0.30 to 0.55% by weight,
Si; 0.15 to 0.45%, Mn; 0.60 to 1.5
5%, S; 0.050% or less, Cr; 0 to 0.30%,
Al: 0.01 to 0.075%, V, Nb, or a mixture thereof; 0.05 to 0.15%, Ti: 0.0 to 0.03
%, B; 0 to 0.003%, N; 0.2923 Ti to
A composition containing 0.02% is treated in a normal melting furnace and melting conditions and cast into an ingot, and then Ac 3 or more to 1300 ° C. depending on each raw material and shape.
Rolling to a certain thickness in the state of hot working at the following temperature, and from 800 to 950 ° C to 500 to 550 ° C 1
A method for producing a high toughness non-heat treated steel, comprising a step of cooling at a cooling rate of 0 to 150 ° C / min.
他の稀土類金属、ミッシュメタル、及びその混合物から
成るグループより選ばれた元素を０．０００１〜０．０
４重量％添加する段階を包含することを特徴とする請求
項４記載の高靭性非調質鋼の製造方法。5. An element selected from the group consisting of Ca, Te, Ce and other rare earth metals, misch metals, and mixtures thereof in the composition in an amount of 0.0001 to 0.0.
The method for producing a high toughness non-heat treated steel according to claim 4, further comprising the step of adding 4% by weight.
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1019900011944A KR930003643B1 (en) | 1990-08-03 | 1990-08-03 | Non-quenched & tempered steel having a high toughness |
| KR910002925 | 1991-02-22 | ||
| KR1990P11944 | 1991-02-22 | ||
| KR1991P2924 | 1991-02-22 | ||
| KR1019910002924A KR930002742B1 (en) | 1991-02-22 | 1991-02-22 | Non-quenched & tempered steel and its method for making |
| KR1991P2925 | 1991-02-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06340946A true JPH06340946A (en) | 1994-12-13 |
Family
ID=27348672
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21622291A Pending JPH06340946A (en) | 1990-08-03 | 1991-08-02 | Non-tempered steel with high toughness and preparation thereof |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH06340946A (en) |
| DE (1) | DE4125648A1 (en) |
| FR (1) | FR2665461B1 (en) |
| GB (2) | GB9116412D0 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011026641A (en) * | 2009-07-23 | 2011-02-10 | Sumitomo Metal Ind Ltd | Non-heat treated steel for induction hardening |
| CN112609127A (en) * | 2020-11-27 | 2021-04-06 | 马鞍山钢铁股份有限公司 | Steel for high-strength and high-toughness drill string adapter and production process thereof |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4343565C1 (en) * | 1993-12-21 | 1995-06-08 | Ver Schmiedewerke Gmbh | Method for producing rail wheels and rail wheel parts |
| GB2287956B (en) * | 1994-03-31 | 1998-02-04 | Daewoo Heavy Ind Co Ltd | Thermal refiningless hot-rolled steel and method of making same |
| DE4432390C2 (en) * | 1994-09-02 | 1998-03-26 | Mannesmann Ag | Process for reducing susceptibility to hot cracking in the production of a low-alloy C-Mn steel |
| DE59607725D1 (en) * | 1996-03-06 | 2001-10-25 | Peddinghaus Carl Dan Gmbh | STEEL MATERIAL WITH HIGH RESISTANCE TO HEAT FOR THE PRODUCTION OF ENGINE PISTON PARTS |
| EP0824602B1 (en) * | 1996-03-06 | 2001-09-19 | CARL DAN. PEDDINGHAUS GMBH & CO. KG | Steel material with high thermal resistance for producing engine piston upper parts |
| FR2765593B1 (en) * | 1997-07-04 | 1999-08-20 | Ascometal Sa | CARBON OR LOW ALLOY STEEL WITH IMPROVED WORKABILITY AND PROCESS FOR THE PREPARATION OF THIS STEEL |
| CN102994895A (en) * | 2012-12-03 | 2013-03-27 | 中天钢铁集团有限公司 | Microalloyed high-strength high-toughness steel for geological drilling and production technology thereof |
| CN103589970B (en) * | 2013-10-24 | 2016-03-30 | 南京钢铁股份有限公司 | The excellent Materials And Manufacturing Processes of Micro Alloying axial workpiece |
| CN117758155A (en) * | 2024-01-29 | 2024-03-26 | 延安嘉盛石油机械有限责任公司 | Oil casing and preparation method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57120616A (en) * | 1981-01-21 | 1982-07-27 | Daido Steel Co Ltd | Production of parts for mechanical structure |
| JPS599122A (en) * | 1982-07-05 | 1984-01-18 | Kawasaki Steel Corp | Manufacture of unnormalized high strength and high toughness steel |
| JPS61204353A (en) * | 1985-03-07 | 1986-09-10 | Nippon Steel Corp | Steel material having superior strength and toughness in as warm forged state |
| JPS64220A (en) * | 1987-06-23 | 1989-01-05 | Nippon Steel Corp | Production of hot forged and non-tempered parts for machine structural purpose |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB411282A (en) * | 1933-05-16 | 1934-06-07 | Robert Owen Jones | Improvements in or relating to electromagnetic motors |
| GB1342582A (en) * | 1970-03-20 | 1974-01-03 | British Steel Corp | Rail steel |
| FR2436825B1 (en) * | 1978-09-20 | 1987-07-24 | Daido Steel Co Ltd | TELLURE AND SULFUR SHELL STEEL HAVING REDUCED ANISOTROPY OF MECHANICAL PROPERTIES AND GOOD COLD FORGING SUITABILITY, AND PROCESS FOR PREPARING THE SAME |
| US4299621A (en) * | 1979-07-03 | 1981-11-10 | Henrik Giflo | High mechanical strength reinforcement steel |
| DE3201204C2 (en) * | 1982-01-16 | 1983-12-22 | M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8900 Augsburg | "Use of a carbon-manganese steel for components with high strength and toughness with simple heat treatment" |
| JPS58199812A (en) * | 1982-05-18 | 1983-11-21 | Kobe Steel Ltd | Manufacture of steel material with superior resistance to stress corrosion cracking due to sulfide |
| US4533405A (en) * | 1982-10-07 | 1985-08-06 | Amax Inc. | Tubular high strength low alloy steel for oil and gas wells |
| DE3434744A1 (en) * | 1984-09-21 | 1986-04-03 | M.A.N.-B & W Diesel GmbH, 8900 Augsburg | Process for producing hot-rolled bars |
| SU1497264A1 (en) * | 1987-09-22 | 1989-07-30 | Всесоюзный научно-исследовательский и конструкторско-технологический институт трубной промышленности | Steel |
| KR930010411B1 (en) * | 1988-07-11 | 1993-10-23 | 니혼 세이코오 가부시끼가이샤 | Rolling bearing |
| US5017335A (en) * | 1989-06-29 | 1991-05-21 | Bethlehem Steel Co. | Microalloyed steel and process for preparing a railroad joint bar |
-
1991
- 1991-07-30 GB GB919116412A patent/GB9116412D0/en active Pending
- 1991-08-01 GB GB9116654A patent/GB2246579B/en not_active Expired - Fee Related
- 1991-08-02 DE DE4125648A patent/DE4125648A1/en not_active Withdrawn
- 1991-08-02 FR FR9109898A patent/FR2665461B1/en not_active Expired - Fee Related
- 1991-08-02 JP JP21622291A patent/JPH06340946A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57120616A (en) * | 1981-01-21 | 1982-07-27 | Daido Steel Co Ltd | Production of parts for mechanical structure |
| JPS599122A (en) * | 1982-07-05 | 1984-01-18 | Kawasaki Steel Corp | Manufacture of unnormalized high strength and high toughness steel |
| JPS61204353A (en) * | 1985-03-07 | 1986-09-10 | Nippon Steel Corp | Steel material having superior strength and toughness in as warm forged state |
| JPS64220A (en) * | 1987-06-23 | 1989-01-05 | Nippon Steel Corp | Production of hot forged and non-tempered parts for machine structural purpose |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011026641A (en) * | 2009-07-23 | 2011-02-10 | Sumitomo Metal Ind Ltd | Non-heat treated steel for induction hardening |
| CN112609127A (en) * | 2020-11-27 | 2021-04-06 | 马鞍山钢铁股份有限公司 | Steel for high-strength and high-toughness drill string adapter and production process thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE4125648A1 (en) | 1992-02-06 |
| GB9116412D0 (en) | 1991-09-11 |
| GB2246579A (en) | 1992-02-05 |
| GB9116654D0 (en) | 1991-09-18 |
| GB2246579B (en) | 1994-11-30 |
| FR2665461B1 (en) | 1994-09-16 |
| FR2665461A1 (en) | 1992-02-07 |
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