JPH0796695B2 - Medium carbon tough steel - Google Patents
Medium carbon tough steelInfo
- Publication number
- JPH0796695B2 JPH0796695B2 JP63197854A JP19785488A JPH0796695B2 JP H0796695 B2 JPH0796695 B2 JP H0796695B2 JP 63197854 A JP63197854 A JP 63197854A JP 19785488 A JP19785488 A JP 19785488A JP H0796695 B2 JPH0796695 B2 JP H0796695B2
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- toughness
- less
- oxide
- steel
- strength
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Description
【発明の詳細な説明】 ［産業上の利用分野］ 本発明は中炭素強靭鋼にかかわり、さらに詳しくは、高
強度・高靭性を必要とする各種機械構造部品の製造に際
して、調質処理をすることなく、十分な材質特性、特に
強度と靭性を製品に付与することを可能にした中炭素強
靭鋼に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a medium carbon toughness steel, and more specifically, a tempering treatment is performed in the production of various mechanical structural parts requiring high strength and high toughness. The present invention relates to a medium carbon toughness steel capable of imparting sufficient material characteristics, particularly strength and toughness, to a product.
［従来の技術］ 従来、高強度・高靭性を必要とする各種機械構造部品
は、主として中炭素鋼を熱間鍛造によって成形後、調質
処理、即ち、焼入れ焼きもどし処理をして使用されてい
る。鋼材の調質処理は、その鋼材の強度と靭性との兼ね
合いを最高度に引き出すための手段として、広く活用さ
れてきた。[Prior Art] Conventionally, various mechanical structural parts that require high strength and high toughness are mainly used by hot-forging medium carbon steel, followed by tempering, that is, quenching and tempering. There is. Heat treatment of steel has been widely used as a means for maximizing the balance between strength and toughness of the steel.
しかし、調質処理は多大なる熱エネルギーを要すること
から、製造コスト低減のためには、調質処理を省略する
事ができる鋼材、即ち熱間鍛造のままで調質材以上の強
度と靭性を確保し得るいわゆる熱間鍛造非調質鋼が必要
になってくる。However, the tempering process requires a great deal of heat energy, so in order to reduce the manufacturing cost, it is possible to omit the tempering process. A so-called hot forged non-heat treated steel that can be secured becomes necessary.
一般に、鋼材の靭性を無視して、強度のみ高くすること
は、非調質であっても、比較的容易であるけれども、こ
のような鋼材は、用途が限定され、従来の調質鋼に代替
できるものではない。In general, it is relatively easy to ignore the toughness of steel materials and increase only the strength even if they are non-tempered, but such steel materials have limited applications and can be replaced by conventional tempered steel. Not something you can do.
これに対して、特開昭56−38448号公報には、Si,Mn等を
多くすることによる地鉄の強化と、Ti,V,Nbによる析出
強化による鋼材の高強度化を図るとともに、鋼中のＮを
0.29×Ti％以上と多くして、窒化物主体のTi,V,Nbの析
出物を生成させることにより、旧オーステナイト粒径を
微細化して、鋼材の高靭性化を図り、熱間鍛造のままで
優れた強度と靭性の確保を可能にした材料が示されてい
る。On the other hand, in JP-A-56-38448, strengthening of the base iron by increasing Si, Mn, etc., and strengthening of the steel material by precipitation strengthening by Ti, V, Nb, N in
By increasing the content to 0.29 × Ti% or more to generate Ti, V, and Nb precipitates mainly composed of nitride, the grain size of the former austenite is refined, the toughness of the steel material is increased, and hot forging is performed. Shows a material that enables to secure excellent strength and toughness.
しかしながら、この材料を用いてもなおかつ、従来の調
質材以上の強度と靭性の保証には未だ十分ではない。However, even if this material is used, it is still not sufficient to guarantee the strength and toughness of the conventional heat-treated material.
一方、特開昭61−117245号公報には、溶接用低温強靭鋼
として、溶接後の冷却過程で、旧オーステナイト粒内に
生成する粒内フェライトの活用により組織を実効的に微
細化し、高靭性化を可能とした鋼材が示されている。し
かしながら、この鋼材は、非調質において強度のグレー
ドが最大60kgf/mm2であり、通常75kgf/mm2以上の強度を
必要とする熱間鍛造非調質鋼としては適用できず、ま
た、この鋼材をベースとして、Ｃ量の増量等により75kg
f/mm2級の強度を確保した場合、この鋼材の基本組成で
は、粒内フェライトによる実効的な組織の微細化は実現
できず、靭性の向上が図られない。すなわち、この鋼材
の技術思想は、直接的にも間接的にも、熱間鍛造非調質
鋼には適用できない。On the other hand, JP-A-61-117245 discloses that as a low-temperature toughness steel for welding, the structure is effectively refined by utilizing the intragranular ferrite generated in the former austenite grains in the cooling process after welding, and high toughness The steel materials that have been made possible are shown. However, this steel material has a maximum strength grade of 60 kgf / mm 2 in non-heat treated, and cannot be applied as hot forged non-heat treated steel that normally requires strength of 75 kgf / mm 2 or more. Based on steel, 75kg due to increased C content
When the strength of f / mm 2 grade is secured, the basic composition of this steel material cannot realize the effective micronization of the microstructure due to the intragranular ferrite, and the toughness cannot be improved. That is, the technical concept of this steel material cannot be directly or indirectly applied to hot forged non-heat treated steel.
以上のように、従来のいかなる技術を用いても、調質材
以上の強度と靭性の保証には未だ十分であるとはいえな
いのが現状である。As described above, it cannot be said that the use of any conventional technique is still sufficient for guaranteeing strength and toughness superior to that of the heat-treated material.
［発明が解決しようとする課題］ 本発明の目的は、熱間鍛造のままで従来の調質材以上の
強度と靭性の保証を可能にした、中炭素強靭鋼を提供し
ようとするものである。[Problems to be Solved by the Invention] An object of the present invention is to provide a medium carbon toughness steel capable of guaranteeing strength and toughness higher than those of conventional heat treated materials in the as-hot-forged state. .
［課題を解決するための手段、および作用］ 本発明者らは、熱間鍛造のままで従来の調質材以上の強
度と靭性の保証を可能にした中炭素強靭鋼を実現するた
めに、鋭意検討を行った結果、Ti,Zr等の酸化物生成元
素を特定の範囲添加し、かつ、特定の範囲の大きさの酸
化物及び酸化物とMnSの複合体の粒子を特定の範囲の個
数含有させ、さらに、S,V,Nを多量添加することによ
り、熱間鍛造のままで微細な組織を実現することが可能
であり、かかる鋼材を用いれば、熱間鍛造のままで従来
の調質材以上の強度と靭性の保証が可能であるという新
規な知見を得て、本発明をなしたものである。[Means and Actions for Solving the Problem] In order to realize a medium carbon toughness steel capable of guaranteeing strength and toughness higher than that of a conventional heat-treated material as it is in hot forging, the present inventors have As a result of intensive studies, Ti, Zr and other oxide-forming elements were added in a specific range, and particles of an oxide and an oxide / MnS composite having a size in a specific range were added in a specific range. It is possible to achieve a fine structure with hot forging by adding S and V and N and adding a large amount of S, V, and N. If such a steel material is used, it is possible to obtain a conventional structure without hot forging. The present invention has been made by obtaining new knowledge that it is possible to guarantee strength and toughness superior to that of a quality material.
即ち、本発明は以上の知見にもとずいてなされたもので
あって、その要旨とするところは、 重量比として、C:0.10％以上〜0.30％未満,Si:0.01〜3.
00％,Mn:0.20〜3.00％,S:0.01〜0.30％,V:0.03〜0.30
％,N:0.005〜0.060％，を含有し、さらに、Ti:0.001〜
0.100％,Zr:0.001〜0.100％,Hf:0.001〜0.200％,Y:0.00
1〜0.150％,La:0.001〜0.150％,Ce:0.001〜0.150％,Ca:
0.001〜0.050％,Mg:0.001〜0.010％のうち１種または２
種以上を含有し、かつ、粒子径が0.1〜10.0μｍである
酸化物及び酸化物とMnSの複合体の粒子を、１×103〜１
×106個/mm3含有し、Al:0.005％以下,P:0.03％以下に制
限し、残部がFe及び不可避的不純物からなることを特徴
とする中炭素強靭鋼にある。That is, the present invention has been made based on the above findings, and the gist thereof is as a weight ratio, C: 0.10% or more to less than 0.30%, Si: 0.01 to 3.
00%, Mn: 0.20 to 3.00%, S: 0.01 to 0.30%, V: 0.03 to 0.30
%, N: 0.005 to 0.060%, and Ti: 0.001 to
0.100%, Zr: 0.001 to 0.100%, Hf: 0.001 to 0.200%, Y: 0.00
1 to 0.150%, La: 0.001 to 0.150%, Ce: 0.001 to 0.150%, Ca:
0.001 to 0.050%, Mg: 0.001 to 0.010%, 1 or 2
1 × 10 3 to 1 particles of an oxide containing at least one kind and having a particle diameter of 0.1 to 10.0 μm and a composite of oxide and MnS
A medium carbon toughness steel characterized by containing x 10 6 pieces / mm 3 and limiting Al: 0.005% or less and P: 0.03% or less, with the balance being Fe and inevitable impurities.
又さらに必要に応じて、Cr:3.0％以下,Mo:1.0％以下,Ni
3.0％以下,Cu:2.0％以下,Nb:0.5％以下のうち１種また
は２種以上を含有するものである。If necessary, Cr: 3.0% or less, Mo: 1.0% or less, Ni
It contains one or more of 3.0% or less, Cu: 2.0% or less, and Nb: 0.5% or less.
以下に、本発明を詳細に説明する。The present invention will be described in detail below.
まず、Ｃは鍛造品の強度を増加させるのに有効な元素で
あるが、0.10％未満では強度が不足し、また0.30％以上
では靭性の劣化を招くため、含有量を0.10％以上〜0.30
％未満とした。First, C is an element effective for increasing the strength of the forged product, but if it is less than 0.10%, the strength is insufficient, and if it is 0.30% or more, the toughness is deteriorated, so the content is 0.10% to 0.30%.
It was less than%.
次にSiは固溶体硬化による強度の増加を図ることを目的
として添加する。この効果は、1.0％超で特に顕著であ
り、1.0％超のSi添加が望ましいが、0.01％〜1.0％でも
十分な効果を示し、0.01％未満ではその効果は不十分で
ある。一方、3.00％を超えるとその効果は飽和し、むし
ろ靭性の劣化を招く。以上の理由から、Siの含有量を0.
01〜3.00％とした。Next, Si is added for the purpose of increasing the strength by solid solution hardening. This effect is particularly remarkable when it exceeds 1.0%, and addition of Si of more than 1.0% is desirable, but 0.01% to 1.0% shows a sufficient effect, and if it is less than 0.01%, the effect is insufficient. On the other hand, if it exceeds 3.00%, the effect is saturated and rather the toughness is deteriorated. For the above reasons, the Si content is set to 0.
It was set to 01 to 3.00%.
また、Mnは焼入れ性の増加によりパーライト分率を増加
させ、鍛造品の強度を増加させるために添加するが、0.
20％未満ではその効果は小さい。また3.00％を超える
と、マルテンサイトを含む組織となり、靭性の劣化を招
く。そのために、Mnの範囲を0.20〜3.00％とした。Further, Mn is added to increase the pearlite fraction due to the increase in hardenability and to increase the strength of the forged product.
If it is less than 20%, the effect is small. On the other hand, if it exceeds 3.00%, the structure will contain martensite, resulting in deterioration of toughness. Therefore, the range of Mn was set to 0.20 to 3.00%.
次にS,V,Nは本発明鋼における重要な元素であり、熱間
鍛造のままで組織を微細化させるために、必須元素とし
て添加する。Next, S, V, and N are important elements in the steel of the present invention, and are added as essential elements in order to refine the structure while hot forging.
まず、Ｓは鋼中でMnS及び酸化物とMnSの複合体として存
在し、組織の微細化に寄与する。この効果は、0.05％超
で特に顕著であり、0.05％超のＳ添加が望ましいが、0.
01％〜0.05％でも十分な効果を示し、0.01％未満ではそ
の効果は不十分である。一方、0.30％を超えるとその効
果は飽和し、むしろ靭性の劣化及び異方性の増加を招
く。以上の理由から、Ｓの含有量を0.01〜0.30％とし
た。First, S exists as MnS and a complex of oxide and MnS in steel and contributes to the refinement of the structure. This effect is particularly remarkable when it exceeds 0.05%, and it is desirable to add S of more than 0.05%.
Even if 01% to 0.05%, the effect is sufficient, and if less than 0.01%, the effect is insufficient. On the other hand, if it exceeds 0.30%, the effect is saturated and rather the toughness deteriorates and the anisotropy increases. For the above reason, the S content is set to 0.01 to 0.30%.
また、V,NはVNの析出挙動を通じて、組織の微細化に寄
与するが、V:0.03％未満、N:0.005％未満ではその効果
は不十分であり、一方、V:0.30％超、N:0.060％超で
は、その効果は飽和し、むしろ析出脆化による靭性の劣
化を招くので、その含有量をV:0.03〜0.30％,N:0.005〜
0.060％とした。In addition, V and N contribute to the refinement of the structure through the precipitation behavior of VN, but if V: less than 0.03% and N: less than 0.005%, the effect is insufficient, while V: more than 0.30%, N : If over 0.060%, the effect is saturated and rather causes deterioration of toughness due to precipitation embrittlement, so the content is V: 0.03-0.30%, N: 0.005-
It was set to 0.060%.
次に本発明鋼においては、Ti,Zr,Hf,Y,La,Ce,Ca,Mgのう
ち１種または２種以上を必須元素として特定の成分範囲
で含有させ、かつ特定の範囲の大きさの酸化物及び酸化
物とMnSの複合体の粒子を特定の範囲の個数含有させ
る。なお、ここでいう酸化物とは、必須元素として添加
するTi,Zr,Hf,Y,La,Ce,Ca,Mgのうち１種または２種以上
の酸化物のことである。これらの元素、酸化物及び酸化
物とMnSの複合体の粒子は、熱間鍛造後の組織を微細化
し、鍛造品の靭性を増加させるために含有させる。しか
しながら、Ti,Zr,Hf,Y,La,Ce,Ca,Mgの含有量が0.001％
未満であるか、又は粒子径が0.1〜10.0μｍの酸化物及
び酸化物とMnSの複合体の粒子の個数が１×103個/mm3未
満であれば、その効果は小さい。ここで、酸化物及び酸
化物とMnSの複合体の粒子径を0.1〜10.0μｍと限定した
のは、0.1μｍ未満及び10μｍ超の酸化物及び酸化物とM
nSの複合体の粒子は、熱間鍛造後の組織の微細化に対し
て効果が小さいためである。一方、Ti:0.100％超、Zr:
0.100％超、Hf:0.200％超、Y:0.150％超、La:0.150％
超、Ce:0.150％超、Ca:0.050％超、Mg:0.010％超を添加
するか、又は粒子径が0.1〜10.0μｍの酸化物及び酸化
物とMnSの複合体の粒子の個数が１×106個/mm3超であれ
ば、熱間鍛造後の組織の微細化に対する効果は飽和し、
むしろ靭性を劣化させる。以上の理由で、各元素の含有
量を、Ti:0.001〜0.100％、Zr:0.001〜0.100％,Hf:0.00
1〜0.200％,Y:0.001〜0.150％,La:0.001〜0.150％,Ce:
0.001〜0.150％,Ca:0.001〜0.050％,Mg:0.001〜0.010％
とし、粒子径が0.1〜10.0μｍの酸化物及び酸化物とMnS
の複合体の個数を１×103〜１×106個/mm3の範囲に限定
した。なお、このような酸化物及び酸化物とMnSの複合
体の粒子の個数を満足するには、例えばその手段の一つ
として、本発明者の一人が特願平１−228643号公報の明
細書の中で提示しているように、鋳込み直前の溶鋼中の
溶存酸素濃度を重量で20〜60ppmの範囲で制御し、酸化
物生成元素の添加後溶鋼をすみやかに鋳型に鋳込み鋳片
を製造することが有効であるが、これにこだわるもので
はなく、かかる酸化物及び酸化物とMnSの複合体の粒子
の個数を満たせるものであれば、いかなる製造手段でも
良い。一方、Alは、鋼中で粗大な酸化物及び酸化物とMn
Sの複合体を形成し、靭性劣化の原因となる。特にAlが
0.005％以上で靭性の劣化が顕著となるため、Alの含有
量を0.005％以下とした。Next, in the steel of the present invention, one or more of Ti, Zr, Hf, Y, La, Ce, Ca, and Mg are contained as an essential element in a specific component range, and the size of the specific range is set. The number of oxide particles and the number of particles of the oxide-MnS composite are contained in a specific range. The oxide mentioned here is an oxide of one or more of Ti, Zr, Hf, Y, La, Ce, Ca, and Mg added as an essential element. The particles of these elements, oxides, and composites of oxides and MnS are contained in order to refine the structure after hot forging and increase the toughness of the forged product. However, the content of Ti, Zr, Hf, Y, La, Ce, Ca, Mg is 0.001%.
If the number is less than 1 or less than 1 × 10 3 particles / mm 3 of the oxide and the oxide-MnS composite having a particle diameter of 0.1 to 10.0 μm, the effect is small. Here, the particle size of the oxide and the composite of the oxide and MnS is limited to 0.1 to 10.0 μm because the oxide and the oxide and the M and M are less than 0.1 μm and more than 10 μm.
This is because the nS composite particles have a small effect on the refinement of the structure after hot forging. On the other hand, Ti: more than 0.100%, Zr:
Over 0.100%, Hf: over 0.200%, Y: over 0.150%, La: 0.150%
Super, Ce: more than 0.150%, Ca: more than 0.050%, Mg: more than 0.010%, or the number of particles of oxides having a particle size of 0.1-10.0 μm and oxide-MnS composites is 1 × If it exceeds 10 6 pieces / mm 3 , the effect on the refinement of the structure after hot forging is saturated,
Rather, it deteriorates toughness. For the above reasons, the content of each element is Ti: 0.001 to 0.100%, Zr: 0.001 to 0.100%, Hf: 0.00
1 to 0.200%, Y: 0.001 to 0.150%, La: 0.001 to 0.150%, Ce:
0.001-0.150%, Ca: 0.001-0.050%, Mg: 0.001-0.010%
And oxides with a particle size of 0.1-10.0 μm and oxides and MnS
The number of composites was limited to the range of 1 × 10 3 to 1 × 10 6 / mm 3 . In order to satisfy the number of particles of such an oxide and a complex of an oxide and MnS, for example, as one of the means, one of the inventors has described the specification of Japanese Patent Application No. 1-228643. , The dissolved oxygen concentration in the molten steel immediately before casting is controlled in the range of 20 to 60 ppm by weight, and after the addition of the oxide-forming element, the molten steel is promptly produced into a cast slab. However, the present invention is not limited to this, and any manufacturing means may be used as long as it can satisfy the number of particles of the oxide and the complex of the oxide and MnS. On the other hand, Al is a coarse oxide in the steel and oxides and Mn
It forms a complex of S and causes deterioration of toughness. Especially Al
Since the deterioration of toughness becomes remarkable when the content is 0.005% or more, the content of Al is set to 0.005% or less.
また、Ｐは鋼中で粒界偏析や中心偏析を起し、靭性劣化
の原因となる。特にＰが0.03％を超えると靭性の劣化が
顕著となるため、0.03％を上限とした。Further, P causes grain boundary segregation or center segregation in steel, which causes deterioration of toughness. In particular, when P exceeds 0.03%, deterioration of toughness becomes remarkable, so 0.03% was made the upper limit.
以上が本発明鋼の基本組成であるが、この他本発明鋼に
おいては、鋼材の焼入れ性を増加させて、鍛造品の強度
を増加させる目的で、Cr,Mo,Ni,Cu,Nbの１種又は２種以
上を含有させることが出来る。しかしながら、これらの
元素の多量添加は、経済性の点で好ましくないため、C
r,Mo,Ni,Cu及びNbの上限をそれぞれ3.0％,1.0％,3.0％,
2.0％及び0.5％とした。Although the above is the basic composition of the present invention steel, in addition to this, in the present invention steel, in order to increase the hardenability of the steel material and increase the strength of the forged product, 1 of Cr, Mo, Ni, Cu, Nb One kind or two or more kinds can be contained. However, addition of a large amount of these elements is not preferable from the economical point of view.
The upper limits of r, Mo, Ni, Cu and Nb are 3.0%, 1.0%, 3.0%,
It was set to 2.0% and 0.5%.
以下に、本発明の効果を実施例により、さらに具体的に
示す。Hereinafter, the effects of the present invention will be described more specifically by way of examples.
［実施例］ 第１表に示す直径50mmの鋼材を、1250℃加熱の後、直径
25mmに熱間鍛造し、得られた鍛造品の強度と靭性の評価
を行った。これらの結果を第２表に示す。[Example] A steel material having a diameter of 50 mm shown in Table 1 was heated at 1250 ° C.
Hot forging was performed to 25 mm, and the strength and toughness of the obtained forged product were evaluated. The results are shown in Table 2.
なお、熱間鍛造のままで従来の調質材以上の強度と靭性
の確保が可能か否かについて、次の基準により判断し
た。The following criteria were used to judge whether or not it is possible to secure the strength and toughness of the conventional tempered material as it is while hot forging.
（１）強度:75kgf/mm2以上、且つ（２）靭性：強度に 応じて2uE20＝15.3−0.095×T.S.kgf−m/cm2以上（調質
用高靭性鍛造用鋼として、一般に用いられている、SMn
鋼の焼入れ焼戻し（550℃焼戻し材の強度と靭性をその
化学成分と併せて第３表に示したが、靭性（2uE20）を
強度（T.S.）について、回帰分析すると、2uE20＝15.3
−0.095×T.S.となるため）。(1) Strength: 75 kgf / mm 2 or more, and (2) Toughness: strength Correspondingly 2u E 20 = 15.3−0.095 × TS kgf−m / cm 2 or more (SMn, which is commonly used as high toughness forging steel for refining, SMn
Quenching and tempering of steel (The strength and toughness of 550 ℃ tempered materials are shown in Table 3 together with their chemical composition. When the toughness ( 2u E 20 ) is regressed with respect to the strength (TS), it is 2u E 20 = 15.3.
-0.095 x TS).
第２表から明らかなように、本発明の鋼は、いずれも熱
間鍛造のままで、75kgf/mm2以上の強度と、強度に応じ
て、2uE20＝15.3−0.095×T.S.kgf−m/cm2以上の靭性を
有することがわかる。As is clear from Table 2, the steels of the present invention were both hot forged and had a strength of 75 kgf / mm 2 or more and, depending on the strength, 2u E 20 = 15.3-0.095 × TSkgf-m / It can be seen that the toughness is cm 2 or more.
一方、比較例17,20は、Ｃ或はMnの含有量がそれぞれ本
発明の範囲を下回った場合であり、ともに強度が不足し
ている。比較例18,19,21,40,41はC,Si,Mn,Al或はＰのい
ずれかの含有量がそれぞれ本発明の範囲を上回った場合
であり、いずれも所定の靭性が得られていない。また、
比較例22,24,26は、S,V,Nのいずれかの含有量がそれぞ
れ本発明の範囲を下回った場合であり、比較例23,25,27
は、S,V,Nのいずれかの含有量がそれぞれ本発明の範囲
を上回った場合であり、いずれも所定の靭性が得られて
いない。さらに、比較例28、29は、Ti、比較令30、31、
32はZr、比較例33はHf、比較例34、35はＹ、比較例36は
La、比較例37はCe、比較例38はCa、比較例39はMgの含有
量がそれぞれ本発明の範囲を上回った場合であり、いず
れも所定の靭性が得られていない。また比較例42,43は
粒子径が0.1〜10.0μｍである酸化物及び酸化物とMnSの
複合体の粒子の個数が本発明の範囲を下回った場合であ
り、比較例44,45,46は粒子径が0.1〜10.0μｍである酸
化物及び酸化物とMnSの複合体の粒子の個数が本発明の
範囲を上回った場合であり、いずれも所定の靭性が得ら
れていない。On the other hand, Comparative Examples 17 and 20 are cases where the content of C or Mn was below the range of the present invention, respectively, and both had insufficient strength. Comparative Examples 18, 19, 21, 40, and 41 are cases in which the content of any of C, Si, Mn, Al, or P exceeds the range of the present invention, and all have a predetermined toughness. Absent. Also,
Comparative Examples 22, 24, 26 are cases where the content of any of S, V, N is below the range of the present invention, and Comparative Examples 23, 25, 27.
Indicates that the content of any one of S, V and N exceeds the range of the present invention, and none of them has a predetermined toughness. Further, Comparative Examples 28 and 29 are Ti, Comparative Order 30, 31,
32 is Zr, Comparative Example 33 is Hf, Comparative Examples 34 and 35 are Y, and Comparative Example 36 is
La, Comparative Example 37 are Ce, Comparative Example 38 is Ca, and Comparative Example 39 is when the content of Mg exceeds the range of the present invention, respectively, and the predetermined toughness is not obtained in any of them. Further, Comparative Examples 42 and 43 are cases where the number of particles of the oxide and the composite of oxide and MnS having a particle diameter of 0.1 to 10.0 μm is below the range of the present invention, and Comparative Examples 44, 45 and 46 are This is the case where the number of particles of the oxide and the oxide-MnS composite having a particle diameter of 0.1 to 10.0 μm exceeds the range of the present invention, and the predetermined toughness is not obtained in any case.
［発明の効果］ 以上述べたごとく、本発明の鋼を用いれば、熱間鍛造ま
まで従来の調質材以上の強度と靭性の確保が可能であ
り、従来必要とした調質処理の省略とそれにともなう製
造コスト低減が可能となり、産業上の効果は極めて顕著
なるものがある。[Effects of the Invention] As described above, when the steel of the present invention is used, it is possible to secure strength and toughness higher than those of conventional tempering materials without hot forging. As a result, manufacturing costs can be reduced, and industrial effects are extremely remarkable.
Claims (2)
〜10.0μｍである酸化物及び酸化物とMnSの複合体の粒
子を、１×103〜１×106個/mm3含有し、 Al:0.005％以下,P:0.03％以下 に制限し、残部がFe及び不可避的不純物からなることを
特徴とする中炭素強靭鋼。1. A weight ratio of C: 0.10% or more to less than 0.30%, Si: 0.01 to 3.00%, Mn: 0.20 to 3.00%, S: 0.01 to 0.30%, V: 0.03 to 0.30%, N: 0.005 ~ 0.060%, Ti: 0.001-0.100%, Zr: 0.001-0.100%, Hf: 0.001-0.200%, Y: 0.001-0.150%, La: 0.001-0.150%, Ce: 0.001-0.150% , Ca: 0.001 to 0.050%, Mg: 0.001 to 0.010%, containing 1 or 2 or more and having a particle size of 0.1
~ 10.0μm oxide and oxide-MnS composite particles are contained 1 × 10 3 ~ 1 × 10 6 particles / mm 3 , Al: 0.005% or less, P: limited to 0.03% or less, A medium carbon toughness steel characterized by the balance being Fe and inevitable impurities.
1〜10.0μｍである酸化物及び酸化物とMnSの複合体の粒
子を、１×103〜１×106個/mm3含有し、さらに、 Cr:3.0％以下,Mo:1.0％以下， Ni:3.0％以下,Cu:2.0％以下， Nb:0.5％以下 のうち１種または２種以上を含有し、 Al:0.005％以下,P:0.03％以下， に制限し、残部がFe及び不可避的不純物からなることを
特徴とする中炭素強靭鋼。2. A weight ratio of C: 0.10% or more to less than 0.30%, Si: 0.01 to 3.00%, Mn: 0.20 to 3.00%, S: 0.01 to 0.30%, V: 0.03 to 0.30%, N: 0.005 ~ 0.060%, Ti: 0.001-0.100%, Zr: 0.001-0.100%, Hf: 0.001-0.200%, Y: 0.001-0.150%, La: 0.001-0.150%, Ce: 0.001-0.150% , Ca: 0.001 to 0.050%, Mg: 0.001 to 0.010%, containing 1 or 2 or more and having a particle size of 0.
Contains 1 × 10 3 to 1 × 10 6 particles / mm 3 of particles of an oxide and a complex of oxide and MnS of 1 to 10.0 μm, and further Cr: 3.0% or less, Mo: 1.0% or less, Contains 1 or more of Ni: 3.0% or less, Cu: 2.0% or less, Nb: 0.5% or less, Al: 0.005% or less, P: 0.03% or less, and balance Fe and unavoidable Medium carbon toughness steel characterized in that it is composed of mechanical impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63197854A JPH0796695B2 (en) | 1988-08-10 | 1988-08-10 | Medium carbon tough steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63197854A JPH0796695B2 (en) | 1988-08-10 | 1988-08-10 | Medium carbon tough steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0247240A JPH0247240A (en) | 1990-02-16 |
| JPH0796695B2 true JPH0796695B2 (en) | 1995-10-18 |
Family
ID=16381442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63197854A Expired - Lifetime JPH0796695B2 (en) | 1988-08-10 | 1988-08-10 | Medium carbon tough steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0796695B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001059170A1 (en) | 2000-02-10 | 2001-08-16 | Aichi Steel Works, Ltd. | Machine structural steel being free of lead, excellent in machinability and reduced in strength anisotropy |
| EP1264909B1 (en) * | 2000-03-06 | 2005-11-30 | Nippon Steel Corporation | Steel excellent in forging and cutting properties |
| US7488396B2 (en) * | 2002-11-15 | 2009-02-10 | Nippon Steel Corporation | Superior in machinability and method of production of same |
| CN112442629B (en) * | 2019-08-28 | 2022-03-18 | 宝山钢铁股份有限公司 | Medium-carbon steel for mechanical structure and manufacturing method thereof |
| CN115354229B (en) * | 2022-08-29 | 2023-08-11 | 西安建筑科技大学 | Non-quenched and tempered steel for crankshaft and processing technology thereof |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5871354A (en) * | 1981-10-20 | 1983-04-28 | Daido Steel Co Ltd | Unnormalized structural steel and its manufacture |
| JPS61117245A (en) * | 1984-11-12 | 1986-06-04 | Nippon Steel Corp | Steel for welding having toughness at low temperature |
-
1988
- 1988-08-10 JP JP63197854A patent/JPH0796695B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0247240A (en) | 1990-02-16 |
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