JPH064889B2 - Method for manufacturing thick ultra high strength steel - Google Patents
Method for manufacturing thick ultra high strength steelInfo
- Publication number
- JPH064889B2 JPH064889B2 JP58004604A JP460483A JPH064889B2 JP H064889 B2 JPH064889 B2 JP H064889B2 JP 58004604 A JP58004604 A JP 58004604A JP 460483 A JP460483 A JP 460483A JP H064889 B2 JPH064889 B2 JP H064889B2
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- Prior art keywords
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- steel
- heat treatment
- high strength
- low temperature
- 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.)
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Description
【発明の詳細な説明】 本発明は厚肉超高張力鋼の製造方法に関するもので、特
に非常に高い強度ですぐれた靱性を必要とする溶接構造
用材料例えば高速衝撃を受ける建設機械材料、容器用材
料として好適な鋼の製造方法に関するものである。Description: TECHNICAL FIELD The present invention relates to a method for producing thick ultra high-strength steel, and particularly to a material for a welded structure requiring very high strength and excellent toughness, for example, a construction machine material subjected to high-speed impact, a container. The present invention relates to a method for producing steel suitable as a material for use in manufacturing.
周知のようにブルドーザーなどで苛酷な耐衝撃摩耗性が
必要な場合高強度を有する厚鋼板が使用されている。近
時これらの機器の大型化と寒冷地環境下での使用という
使用条件の一層の苛酷化が相俟って、低コストで低温下
で耐衝撃摩耗性にすぐれ、かつ高靱性を有する厚肉の強
靱鋼の開発が強く求められている。As is well known, a thick steel plate having high strength is used in a bulldozer or the like when severe impact wear resistance is required. In recent years, due to the larger size of these devices and the more severe operating conditions of use in cold regions, a thick wall with excellent impact wear resistance at low cost at low temperature and high toughness There is a strong demand for the development of high strength steel.
従来本発明で対象とする板厚４０mm以上で引張り強さ９
０Kgf/mm2以上を有する厚肉強靱鋼としては高圧力容器
用にＣ量が低く合金元素を大量に添加したＮｉ−Ｃｒ−
Ｍｏ鋼が知られているが、これはコスト的に高価すぎ特
定の用途に限定される。他方、0.4〜0.5％Ｃを含有し比
較的合金添加量の少ないＮｉ−Ｃｒ−Ｍｏ鋼が知られて
いるが、該鋼の場合には低温靱性が低いこと、溶接が困
難であること、のほか焼割れ配慮から急冷が不可であり
マスプロダクションには不向きという問題がある。Conventionally, in the present invention, a plate thickness of 40 mm or more and a tensile strength of 9
As a thick-walled tough steel with 0 Kgf / mm 2 or more, Ni-Cr- with low C content and large addition of alloying elements for high pressure vessels
Mo steel is known, but it is too costly and limited to specific applications. On the other hand, a Ni-Cr-Mo steel containing 0.4 to 0.5% C and having a relatively small alloy addition amount is known, but in the case of the steel, low temperature toughness is low and welding is difficult. Another problem is that rapid cooling is not possible due to consideration of quenching cracks and is not suitable for mass production.
本発明は、このような問題点を有利に解決するために多
数の実験と検討を行なった結果なされたものであり、適
量のＣ量と適切な化学成分と焼入れ焼戻し熱処理の組合
せにより、低コストでマスプロダクションが可能で９０
Kgf/mm2以上の高強度を有し、かつ高靱性板厚方向均一
性を有する板厚４０mm以上の厚肉強靱鋼の製造方法を提
供することを目的とし、その要旨は、（以下の記載にお
いて％は、すべてwt％を示す。） (1) Ｃ：0.20〜0.35％、Ｓｉ：1.0％以下、 Ｍｎ：0.30〜1.5％、Ｃｒ：0.3〜2.5％ Ｎｉ：2.0〜4.5％、Ｍｏ：0.2〜1.0％ Ａｌ：0.002〜0.1％を含有し、かつＭｎ／Ｃｒ：1.5以
下とし、残りが、不可避不純物およびＦｅからなる鋼を
熱間加工して所定の板厚としたのち、焼入れ熱処理を行
ない、その後焼戻し熱処理を施すこと、を特徴とする引
張り強さ９０Kgf/mm2以上の厚肉超高張力鋼の製造方
法。The present invention has been made as a result of numerous experiments and studies in order to advantageously solve such problems, and by combining a proper amount of C, an appropriate chemical component, and quenching and tempering heat treatment, low cost Mass production is possible with 90
An object of the present invention is to provide a method for producing a thick-walled tough steel having a plate thickness of 40 mm or more having high strength of Kgf / mm 2 or more and high toughness uniformity in the plate thickness direction. % Indicates all wt%.) (1) C: 0.20 to 0.35%, Si: 1.0% or less, Mn: 0.30 to 1.5%, Cr: 0.3 to 2.5% Ni: 2.0 to 4.5%, Mo: 0.2 ~ 1.0% Al: 0.002-0.1% and Mn / Cr: 1.5 or less, the rest is steel consisting of unavoidable impurities and Fe, hot-worked to a predetermined plate thickness, and then subjected to quenching heat treatment. A method for producing a thick ultra high strength steel having a tensile strength of 90 Kgf / mm 2 or more, characterized by performing a tempering heat treatment thereafter.
(2) Ｃ：0.20〜0.35％、Ｓｉ：1.0％以下 Ｍｎ：0.30〜1.50％、Ｃｒ：0.3〜2.5％、 Ｎｉ：2.0〜4.5％、Ｍｏ：0.2〜1.0％、 Ａｌ：0.002〜0.1％を含有し、かつＭｎ／Ｃｒ：1.5以
下とし、さらに Ｖ：0.1％以下，Ｎｂ：0.1％以下，Ｂ：0.01％以下，お
よびＣｕ：2.0％以下からなる強度改善元素群をこの範
囲で１種または２種以上含有し、残りが不可避不純物お
よびＦｅからなる鋼を熱間加工して所定の板厚としたの
ち、焼入れ熱処理を行い、その後焼戻し熱処理を施すこ
と、を特徴とする引張り強さ９０Kgf/mm2以上の厚肉超
高張力鋼の製造方法。(2) C: 0.20 to 0.35%, Si: 1.0% or less Mn: 0.30 to 1.50%, Cr: 0.3 to 2.5%, Ni: 2.0 to 4.5%, Mo: 0.2 to 1.0%, Al: 0.002 to 0.1% One or more Mn / Cr: 1.5 or less, V: 0.1% or less, Nb: 0.1% or less, B: 0.01% or less, and Cu: 2.0% or less within this range. Tensile strength of 90 Kgf / characterized in that steel containing two or more kinds and the rest consisting of unavoidable impurities and Fe is hot-worked to a predetermined plate thickness, and then subjected to quenching heat treatment and then tempering heat treatment. Method for manufacturing thick ultra high strength steel of mm 2 or more.
(3) Ｃ：0.20〜0.35％，Ｓｉ：1.0％以下，Ｍｎ：0.30
〜1.50％，Ｃｒ：0.3〜2.5％，Ｎｉ：2.0〜4.5％，Ｍ
ｏ：0.2〜1.0％，Ａｌ：0.002〜0.1％を含有し、かつＭ
ｎ／Ｃｒ：1.5以下とし、さらにＴｉ：0.1％以下および
Ｃａ：0.1％以下からなる低温靱性改善元素群をこの範
囲で１種または２種含有し、残りが不可避不純物および
Ｆｅからなる鋼を熱間加工して所定の板厚としたのち、
焼入れ熱処理を行い、その後焼戻し熱処理を施すこと、
を特徴とする引張り強さ９０Kgf/mm2以上の厚肉超高張
力鋼の製造方法。(4) Ｃ：0.20〜0.35％，Ｓｉ：1.0％
以下，Ｍｎ：0.30〜1.50％，Ｃｒ：0.3〜2.5％，Ｎｉ：
2.0〜4.5％，Ｍｏ：0.2〜1.0％，Ａｌ：0.002〜0.1％を
含有し、かつＭｎ／Ｃｒ：1.5以下とし、さらにＶ：0.1
％以下，Ｎｂ：0.1％以下，Ｂ：0.01％以下およびＣ
ｕ：2.0％以下からなる強度改善元素群をこの範囲で１
種または２種以上と、Ｔｉ：0.1％以下およびＣａ：0.1
％以下からなる低温靱性改善元素群をこの範囲で１種ま
たは２種含有し、残りが不可避不純物およびＦｅからな
る鋼を熱間加工して所定の板厚としたのち、焼入れ熱処
理を行い、その後焼戻し熱処理を施すこと、を特徴とす
る引張り強さ９０Kgf/mm2以上の厚肉超高張力鋼の製造
方法、である。(3) C: 0.20 to 0.35%, Si: 1.0% or less, Mn: 0.30
~ 1.50%, Cr: 0.3-2.5%, Ni: 2.0-4.5%, M
o: 0.2-1.0%, Al: 0.002-0.1%, and M
n / Cr: 1.5 or less, Ti: 0.1% or less and Ca: 0.1% or less, one or two kinds of low temperature toughness improving element groups are contained in this range, and the balance is steel containing inevitable impurities and Fe. After processing to a predetermined plate thickness,
Quenching heat treatment, then tempering heat treatment,
A method for producing a thick ultra high strength steel having a tensile strength of 90 Kgf / mm 2 or more. (4) C: 0.20 to 0.35%, Si: 1.0%
Below, Mn: 0.30 to 1.50%, Cr: 0.3 to 2.5%, Ni:
2.0 to 4.5%, Mo: 0.2 to 1.0%, Al: 0.002 to 0.1%, and Mn / Cr: 1.5 or less, further V: 0.1
% Or less, Nb: 0.1% or less, B: 0.01% or less and C
u: Strength group consisting of 2.0% or less is 1 in this range
Species or two or more and Ti: 0.1% or less and Ca: 0.1
% Or less of a low temperature toughness improving element group within this range, and the rest consisting of unavoidable impurities and Fe is hot-worked to a predetermined plate thickness, then subjected to quenching heat treatment, and then A method for producing a thick ultra high strength steel having a tensile strength of 90 Kgf / mm 2 or more, which is characterized by performing tempering heat treatment.
即ち、本発明は、従来の溶接構造用鋼としては考えられ
ない。高炭素を含有し、さらにCr,Ni,Moといった合金元
素を低目に設定した高炭素鋼を焼入れ焼戻すことにより
４０mm以上の板厚で９０Kgf/mm2以上の高強度を有する
超高張力鋼が安価に得られる製造方法である。That is, the present invention is not considered as a conventional welded structural steel. Ultra-high-strength steel containing high carbon and high strength of 90 Kgf / mm 2 or more at a plate thickness of 40 mm or more by quenching and tempering high carbon steel in which alloy elements such as Cr, Ni, Mo are set to be low. Is an inexpensive manufacturing method.
この場合、得られた鋼のミクロ組織は高炭素マルテンサ
イトであり、このミクロ組織によって高強度になること
は知られていたが、高い低温靱性を得ることは常識外で
あり、低温靱性が低いという欠点があった。In this case, the microstructure of the obtained steel is high carbon martensite, and it was known that the microstructure provides high strength, but it is uncommon to obtain high low temperature toughness and low low temperature toughness. There was a drawback.
本発明は高炭素マルテンサイト組織の欠点である低温靱
性を改善すべく多数の実験を繰返した結果、Ｍｎ／Ｃｒ
を1.5以下とすることにより高い低温靱性を得ることが
可能であることを見い出し、高炭素マルテンサイト組織
特有の高強度に加えて高い低温靱性の両立を可能とした
ものである。The present invention repeated a number of experiments to improve the low temperature toughness, which is a drawback of the high carbon martensite structure, and as a result, Mn / Cr was obtained.
It was found that high low temperature toughness can be obtained by setting the ratio to 1.5 or less, and it is possible to achieve both high low temperature toughness in addition to the high strength peculiar to the high carbon martensite structure.
第１図は0.30％Ｃ−3.0％Ｎｉ−0.5％ＭｏをベースにＭ
ｎ／Ｃｒを0.05〜1.8まで変化させた鋼をオーステナイ
ト化後急冷し（焼入）その後６３０℃で焼戻し熱処理を
施したときの低温靱性とＭｎ／Ｃｒとの関係を示したも
ので、この図から、0.30％という高炭素を含有し焼入れ
焼戻しによって得られる高炭素マルテンサイト組織鋼に
おいて、Ｍｎ／Ｃｒを低くすることにより低温靱性の向
上をはかることができることを見い出し、本発明を完成
させたものである。Figure 1 shows M based on 0.30% C-3.0% Ni-0.5% Mo.
This graph shows the relationship between low temperature toughness and Mn / Cr when a steel with n / Cr varied from 0.05 to 1.8 was austenitized, then rapidly cooled (quenched) and then tempered at 630 ° C. From the above, it was found that in a high carbon martensitic steel containing 0.30% of high carbon and obtained by quenching and tempering, it is possible to improve the low temperature toughness by lowering Mn / Cr, and completed the present invention. Is.
次に本発明における成分限定理由を述べる。Next, the reasons for limiting the components in the present invention will be described.
Ｃ：Ｃは低コストで強度を確保するため0.20％以上は必
要である。一方0.35％を越えると母材低温靱性の低下が
大きくなることと溶接が困難になること及び焼割れ感受
性が著しく高くなるため、0.35％以下とする。C: 0.20% or more is necessary for C to secure strength at low cost. On the other hand, if it exceeds 0.35%, the low-temperature toughness of the base material is greatly deteriorated, welding becomes difficult, and the susceptibility to quench cracking is significantly increased, so the content is made 0.35% or less.
Ｓｉ：Ｓｉは製鋼時脱酸元素として添加されることのほ
か、強度向上にも有用である。しかし1.0％を越えると
低温靱性の低下が著しいため、1.0％以下とする。Si: Si is not only added as a deoxidizing element during steel making, but also useful for improving strength. However, if it exceeds 1.0%, the low temperature toughness is significantly deteriorated, so it is made 1.0% or less.
Ｍｎ：Ｍｎは安価に強度を向上できる元素であるが高強
度を得るために0.30％以上の添加が必要である。しかし
1.50％を越える添加は低温靱性を損うため、0.30〜1.50
％に限定する。Mn: Mn is an element that can inexpensively improve the strength, but it is necessary to add 0.30% or more to obtain high strength. However
Addition of more than 1.50% impairs low temperature toughness, so 0.30 to 1.50
Limited to%.
Ｃｒ：Ｃｒは鋼の焼入性を高めて強度向上に有用であり
この効果を得るには0.3％以上の添加が必要である。し
かし2.5％を越える添加は低温靱性の低下が生じるため
0.3〜2.5％に限定する。Cr: Cr is useful for enhancing the hardenability of steel and improving the strength, and in order to obtain this effect, addition of 0.3% or more is necessary. However, addition of more than 2.5% causes deterioration of low temperature toughness.
Limited to 0.3-2.5%.
Ｎｉ：Ｎｉは鋼の低温靱性向上に有用な元素であるが、
2.0％未満では靱性向上効果が少ない。一方4.5％を越え
る添加は鋼材のコストを著しく高め経済上不利であるた
め4.5％以下とする。Ni: Ni is an element useful for improving the low temperature toughness of steel,
If it is less than 2.0%, the effect of improving toughness is small. On the other hand, the addition of more than 4.5% significantly increases the cost of the steel material and is economically disadvantageous, so the content is made 4.5% or less.
Ｍｏ：Ｍｏは強度、靱性の向上に有用であるので添加さ
れるが、0.2％未満では効果がない。一方１％を越える
添加は強度が上がりすぎるうえに低温靱性の低下を招く
ため、上限は１％以下とする。Mo: Mo is added because it is useful for improving strength and toughness, but if less than 0.2%, it has no effect. On the other hand, the addition of more than 1% causes the strength to increase too much and also causes deterioration of the low temperature toughness, so the upper limit is made 1% or less.
Ａｌ：Ａｌは鋼の脱酸に0.002％は必要である。一方0.1
％を越える添加は鋼の清浄性を阻害する。このため0.00
2〜0.1％と限定する。Al: Al requires 0.002% for deoxidation of steel. Meanwhile 0.1
Additions in excess of% impair the cleanliness of the steel. Therefore 0.00
Limited to 2 to 0.1%.
Ｍｎ／Ｃｒ：Ｍｎ／Ｃｒを1.5以下としたのは第１図に
示したとおり、Ｍｎ／Ｃｒの上昇が低温靱性を低下させ
る大きな要因であるため上限を1.5とした。As shown in FIG. 1, Mn / Cr: Mn / Cr was set to 1.5 or less because the increase in Mn / Cr is a major factor in lowering the low temperature toughness, so the upper limit was made 1.5.
本発明は以上の成分を必須の成分とするが要求される鋼
の特性に応じて第２〜４発明においてＶ，Ｎｂ，Ｂおよ
びＣｕの強度改善元素群を１種または２種以上、Ｔｉお
よびＣａの靱性改善元素群を１種または２種含有、添加
する。ここで、Ｖ，Ｎｂ，ＢおよびＣｕは強度を改善す
るという均等的作用を持つものであるが、それぞれ、0.
1％、0.1％、0.01％および2.0％を超えると低温靱性を
損なうので、これを上限とする。また、ＴｉおよびＣａ
については、前者は細粒化、後者は脱酸を良好にし、介
在物を減少することで低温靱性を改善するという均等的
作用を持つものであるが、何れも0.1％を超えると、逆
に低温靱性を損なうので、これを上限とする。The present invention uses the above components as essential components, but according to the required properties of the steel, in the second to fourth inventions, one or more of the strength improving element groups of V, Nb, B and Cu, Ti and One or two Ca toughness improving element groups are contained and added. Here, V, Nb, B, and Cu have an equal effect of improving the strength, but each has a value of 0.
If it exceeds 1%, 0.1%, 0.01% or 2.0%, the low temperature toughness is impaired, so this is the upper limit. Also, Ti and Ca
Regarding the above, the former has the equivalent effect of improving the low temperature toughness by making the particles finer and the latter improving the deoxidation and reducing the inclusions. Since it impairs the low temperature toughness, this is the upper limit.
次いで、不純物として不可避的に含有するＰ，Ｓについ
ては特に限定するものではないが、鋼の清浄性を通じて
材質を安定化するため少い程よくこの観点からＰは0.01
5％以下、Ｓは0.010％以下が望ましい。Next, P and S that are unavoidably contained as impurities are not particularly limited, but in order to stabilize the material through the cleanliness of the steel, P is 0.01% from this viewpoint.
5% or less and S is preferably 0.010% or less.
次にこのような成分組成の鋼の溶製に際しては従来公知
の溶製法でよく、また熱間加工も公知の熱間圧延もしく
は熱間鍛造あるいはこれら両者を併用して所定の板厚と
すれば良い。Next, when melting steel having such a composition, a conventionally known melting method may be used, and hot working may be performed by known hot rolling or hot forging, or by using both of them together to obtain a predetermined plate thickness. good.
次に焼入れ焼戻し熱処理について述べる。Next, quenching and tempering heat treatment will be described.
焼入れ熱処理は、熱間加工によって所定の板厚としたの
ち厚肉材に高強度を付与するために、速やかにＡｒ３以
上の温度からオンラインで急冷するか、一旦放冷によっ
て冷却し次いでＡｃ３点以上に再加熱しＡｃ３点以上か
ら急冷するの何れかの焼入れ熱処理を施こす。In the quenching heat treatment, in order to impart a high strength to the thick-walled material after hot-working it to a predetermined plate thickness, it is rapidly cooled online from a temperature of Ar 3 or higher, or once cooled by allowing it to cool and then Ac 3 A quenching heat treatment of reheating to a point or higher and quenching from an Ac point of 3 or higher is performed.
次いで施こす焼戻し熱処理は、焼入れ熱処理後の低温靱
性回復を狙いとし、フェライト域での焼戻し熱処理であ
ることが必要で、このためＡｃ１点以下で焼戻す。Next, the tempering heat treatment to be applied is aimed at recovering the low temperature toughness after the quenching heat treatment, and it is necessary to be the tempering heat treatment in the ferrite region. Therefore, tempering is performed at an Ac 1 point or less.
次に実施例を比較例とともに挙げる。Next, examples will be given together with comparative examples.
第１表に示す化学組成の鋼片を第２表に示す板厚に熱間
圧延するとともに引き続き第２表に示す焼入れ温度、焼
戻し温度での熱処理を行った。得られた鋼板の機械的性
質を併せて第２表に示す。Steel pieces having the chemical composition shown in Table 1 were hot-rolled to the plate thickness shown in Table 2 and subsequently heat-treated at the quenching temperature and tempering temperature shown in Table 2. Table 2 also shows the mechanical properties of the obtained steel sheets.
すなわち、Ｇ，Ｈ，Ｉは比較例を示し、何れもオフライ
ンで熱処理したもので、ＧはＣ量が低いため、靱性は良
好なるも強度が低い。ＨはＣ量が高いため強度は高いが
靱性値は低い。ＩはＭｎ／Ｃｒの値が高すぎるため靱性
レベルが低い水準となっている。 That is, G, H, and I show comparative examples, and all of them are heat-treated off-line. Since G has a low C content, toughness is good but strength is low. Since H has a high C content, the strength is high, but the toughness value is low. I has a low toughness level because the value of Mn / Cr is too high.
Ａ，Ｂは本発明(1)の実施例に相当し、オフラインＱＴ
処理したもので、強度、靱性共に良好な値を示してい
る。Ｃ、Ｄ、Ｅは本発明（４）の実施例に相当し、Ｃは
Ｃｕ，Ｃａ添加したものを用いてオンライン焼入れとオ
フライン焼入れを施した例、ＤはＶ，Ｃａ添加したもの
をオフラインＱＴ処理した例、ＥはＣｕ，Ｖ，Ｂ，Ｔｉ
を添加したものを用いてオンライン焼入れ、オフライン
焼入れを施した例、Ｆ、Ｊ、Ｋは本発明（２）の実施例
に相当し、ＦはＣｕ，Ｎｂを添加したものをオフライン
ＱＴ処理した例であり、ＪはＶ、ＫはＣｕを添加しそれ
ぞれオンライン焼入れした例、Ｌ、Ｍは本発明（３）の
実施例に相当し、ＬはＴｉ添加、ＭはＴｉ，Ｃａを添加
しそれぞれオフライン焼入れした例であり、何れの例に
おいても強度、靱性共に良好な値を示す。A and B correspond to the embodiment of the present invention (1), and the offline QT
The treated material shows good strength and toughness. C, D and E correspond to the embodiment of the present invention (4), C is an example of online quenching and offline quenching using Cu and Ca added, and D is offline QT of V and Ca added. Treated example, E is Cu, V, B, Ti
Examples in which on-line quenching and off-line quenching are performed using the alloys with addition of F, J, and K correspond to the examples of the present invention (2), and F is an example in which Cu and Nb are added and subjected to offline QT treatment. Where J is V, K is an example of online quenching with Cu added, L and M correspond to the embodiment of the present invention (3), L is Ti added, M is Ti and Ca is offline, respectively. It is an example of quenching, and in all cases, both strength and toughness show good values.
以上の如く本発明は高炭素鋼を用いて高価なＣｒ，Ｍ
ｏ，Ｎｉといった合金元素含有量を低目に設定し、これ
を焼入れ焼戻すことにより、４０mm以上の板厚で９０Kg
f/mm2以上の高強度と良好な高い低温靱性を有する厚肉
鋼板を安価に得られるようになしたものであり産業上そ
の効果は大きい。As described above, the present invention uses high carbon steel and is expensive for Cr and M.
By setting the content of alloying elements such as o and Ni to a low value and quenching and tempering this, 90 kg at a plate thickness of 40 mm or more
A thick steel plate having high strength of f / mm 2 or more and good low temperature toughness can be obtained at low cost, and its effect is industrially significant.
第１図はＭｎ／Ｃｒと低温靱性の関係を示す説明図であ
る。FIG. 1 is an explanatory diagram showing the relationship between Mn / Cr and low temperature toughness.
Claims (4)
下，Ｍｎ：0.30〜1.50wt％，Ｃｒ：0.3〜2.5wt％，Ｎ
ｉ：2.0〜4.5wt％，Ｍｏ：0.2〜1.0wt％，Ａｌ：0.002
〜0.1wt％を含有し、かつＭｎ／Ｃｒ：1.5以下とし、残
りが不可避不純物およびＦｅからなる鋼を熱間加工して
所定の板厚としたのち、焼入れ熱処理を行い、その後焼
戻し熱処理を施すこと、を特徴とする引張り強さ９０Kg
f/mm2以上の厚肉超高張力鋼の製造方法。1. C: 0.20 to 0.35 wt%, Si: 1.0 wt% or less, Mn: 0.30 to 1.50 wt%, Cr: 0.3 to 2.5 wt%, N
i: 2.0 to 4.5 wt%, Mo: 0.2 to 1.0 wt%, Al: 0.002
Steel containing 0.1 to 0.1 wt% and Mn / Cr: 1.5 or less, and the balance being unavoidable impurities and Fe is hot-worked to a predetermined plate thickness, followed by quenching heat treatment and then tempering heat treatment. Tensile strength characterized by 90Kg
Method for manufacturing thick ultra high strength steel with f / mm 2 or more.
下，Ｍｎ：0.30〜1.50wt％，Ｃｒ：0.3〜2.5wt％，Ｎ
ｉ：2.0〜4.5wt％，Ｍｏ：0.2〜1.0wt％，Ａｌ：0.002
〜0.1wt％を含有し、かつＭｎ／Ｃｒ：1.5以下とし、さ
らに Ｖ：0.1wt％以下，Ｎｂ：0.1wt％以下，Ｂ：0.01wt％以
下，およびＣｕ：2.0wt％以下からなる強度改善元素群
をこの範囲で１種または２種以上を含有し、残りが不可
避不純物およびＦｅからなる鋼を熱間加工して所定の板
厚としたのち、焼入れ熱処理を行い、その後焼戻し熱処
理を施すこと、を特徴とする引張り強さ９０Kgf/mm2以
上の厚肉超高張力鋼の製造方法。2. C: 0.20 to 0.35 wt%, Si: 1.0 wt% or less, Mn: 0.30 to 1.50 wt%, Cr: 0.3 to 2.5 wt%, N
i: 2.0 to 4.5 wt%, Mo: 0.2 to 1.0 wt%, Al: 0.002
To 0.1 wt% and Mn / Cr: 1.5 or less, V: 0.1 wt% or less, Nb: 0.1 wt% or less, B: 0.01 wt% or less, and Cu: 2.0 wt% or less Steel containing one or more elements in this range and the rest consisting of unavoidable impurities and Fe is hot-worked to a predetermined plate thickness, then subjected to quenching heat treatment and then tempering heat treatment. A method for producing a thick ultra high strength steel having a tensile strength of 90 Kgf / mm 2 or more.
下，Ｍｎ：0.30〜1.50wt％，Ｃｒ：0.3〜2.5wt％，Ｎ
ｉ：2.0〜4.5wt％，Ｍｏ：0.2〜1.0wt％，Ａｌ：0.002
〜0.1wt％を含有し、かつＭｎ／Ｃｒ：1.5以下とし、さ
らに Ｔｉ：0.1wt％以下およびＣａ：0.1wt％以下からなる低
温靱性改善元素群をこの範囲で１種または２種含有し、
残りが不可避不純物およびＦｅからなる鋼を熱間加工し
て所定の板厚としたのち、焼入れ熱処理を行い、その後
焼戻し熱処理を施すこと、を特徴とする引張り強さ９０
Kgf/mm2以上の厚肉超高張力鋼の製造方法。3. C: 0.20 to 0.35 wt%, Si: 1.0 wt% or less, Mn: 0.30 to 1.50 wt%, Cr: 0.3 to 2.5 wt%, N
i: 2.0 to 4.5 wt%, Mo: 0.2 to 1.0 wt%, Al: 0.002
To 0.1 wt% and Mn / Cr: 1.5 or less, and Ti: 0.1 wt% or less and Ca: 0.1 wt% or less, one or two kinds of low temperature toughness improving element groups in this range,
Tensile strength of 90, characterized in that after the steel consisting of the balance unavoidable impurities and Fe is hot-worked to have a predetermined plate thickness, quenching heat treatment is performed, and then tempering heat treatment is performed.
A method for manufacturing thick ultra high strength steel of Kgf / mm 2 or more.
下，Ｍｎ：0.30〜1.50wt％，Ｃｒ：0.3〜2.5wt％，Ｎ
ｉ：2.0〜4.5wt％，Ｍｏ：0.2〜1.0wt％，Ａｌ：0.002
〜0.1wt％を含有し、かつＭｎ／Ｃｒ：1.5以下とし、さ
らに Ｖ：0.1wt％以下，Ｎｂ：0.1wt％以下，Ｂ：0.01wt％以
下，およびＣｕ：2.0wt％以下からなる強度改善元素群
をこの範囲で１種または２種以上と、 Ｔｉ：0.1wt％以下およびＣａ：0.1wt％以下からなる低
温靱性改善元素群をこの範囲で１種または２種含有し、
残りが不可避不純物およびＦｅからなる鋼を熱間加工し
て所定の板厚としたのち、焼入れ熱処理を行い、その後
焼戻し熱処理を施すこと、を特徴とする引張り強さ９０
Kgf/mm2以上の厚肉超高張力鋼の製造方法。4. C: 0.20 to 0.35 wt%, Si: 1.0 wt% or less, Mn: 0.30 to 1.50 wt%, Cr: 0.3 to 2.5 wt%, N
i: 2.0 to 4.5 wt%, Mo: 0.2 to 1.0 wt%, Al: 0.002
To 0.1 wt% and Mn / Cr: 1.5 or less, V: 0.1 wt% or less, Nb: 0.1 wt% or less, B: 0.01 wt% or less, and Cu: 2.0 wt% or less 1 or 2 or more element groups within this range, and 1 or 2 or more low temperature toughness improving element groups consisting of Ti: 0.1 wt% or less and Ca: 0.1 wt% or less within this range,
A tensile strength of 90, which is characterized in that a steel consisting of the unavoidable impurities and Fe is hot-worked to a predetermined plate thickness, followed by quenching heat treatment and then tempering heat treatment.
A method for manufacturing thick ultra high strength steel of Kgf / mm 2 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58004604A JPH064889B2 (en) | 1983-01-14 | 1983-01-14 | Method for manufacturing thick ultra high strength steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58004604A JPH064889B2 (en) | 1983-01-14 | 1983-01-14 | Method for manufacturing thick ultra high strength steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59129724A JPS59129724A (en) | 1984-07-26 |
| JPH064889B2 true JPH064889B2 (en) | 1994-01-19 |
Family
ID=11588640
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58004604A Expired - Lifetime JPH064889B2 (en) | 1983-01-14 | 1983-01-14 | Method for manufacturing thick ultra high strength steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH064889B2 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6173834A (en) * | 1984-09-12 | 1986-04-16 | ベルヘム、ウント、シヤ−ベルク、ゲゼルシヤフト、ミツト、ベシユレンクテル、ハフツング | Production of mold forging beater of agricultural machine using special steel alloy as material |
| JPS6213535A (en) * | 1985-07-12 | 1987-01-22 | Kawasaki Steel Corp | Manufacture of high tension steel plate |
| JPS63105924A (en) * | 1986-10-21 | 1988-05-11 | Nippon Steel Corp | Manufacture of steel plate having superior toughness at low temperature |
| DE4223895C1 (en) * | 1992-07-21 | 1994-03-17 | Thyssen Stahl Ag | Process for the production of thick armored sheets |
| AT414341B (en) | 2003-11-07 | 2010-12-15 | Boehler Edelstahl Gmbh & Co Kg | STEEL FOR CHEMICALS - PLANTS - COMPONENTS |
| JP6179977B2 (en) * | 2013-05-22 | 2017-08-16 | 株式会社日本製鋼所 | High-strength steel with excellent high-pressure hydrogen environment embrittlement resistance and method for producing the same |
| CN104862611B (en) * | 2015-05-12 | 2017-02-01 | 河南省万隆精密铸造股份有限公司 | Cast material for casting wear-resisting centrifugal cylinder and casting technology thereof |
| CN106521316B (en) * | 2016-11-15 | 2018-08-07 | 江阴兴澄特种钢铁有限公司 | Carbon and low-alloy round steel and its manufacturing method in a kind of fastener high-hardenability |
| JP2024015532A (en) | 2020-07-28 | 2024-02-06 | 日本製鉄株式会社 | wear resistant steel |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS583011B2 (en) * | 1978-11-30 | 1983-01-19 | 住友金属工業株式会社 | Manufacturing method of steel plate with stable strength and toughness by direct quenching and tempering |
| JPS55104427A (en) * | 1979-02-02 | 1980-08-09 | Kawasaki Steel Corp | Production of steel for low temperature |
| JPS5952687B2 (en) * | 1979-08-24 | 1984-12-21 | 住友金属工業株式会社 | Manufacturing method of tempered high-strength steel plate with excellent low-temperature toughness |
| JPS57158320A (en) * | 1981-03-25 | 1982-09-30 | Sumitomo Metal Ind Ltd | Production of high tensile steel plate of good weldability |
-
1983
- 1983-01-14 JP JP58004604A patent/JPH064889B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59129724A (en) | 1984-07-26 |
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