JPH01201442A - Steel for thread rolling die - Google Patents
Steel for thread rolling dieInfo
- Publication number
- JPH01201442A JPH01201442A JP2716288A JP2716288A JPH01201442A JP H01201442 A JPH01201442 A JP H01201442A JP 2716288 A JP2716288 A JP 2716288A JP 2716288 A JP2716288 A JP 2716288A JP H01201442 A JPH01201442 A JP H01201442A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- less
- carbide
- area ratio
- toughness
- 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
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 56
- 239000010959 steel Substances 0.000 title claims abstract description 56
- 238000005096 rolling process Methods 0.000 title claims abstract description 38
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 10
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 10
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 9
- 229910052720 vanadium Inorganic materials 0.000 claims abstract description 9
- 229910052758 niobium Inorganic materials 0.000 claims abstract description 8
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 5
- 229910052742 iron Inorganic materials 0.000 claims abstract description 4
- 150000001247 metal acetylides Chemical class 0.000 claims description 19
- 239000012535 impurity Substances 0.000 claims description 11
- 230000008018 melting Effects 0.000 claims description 9
- 238000002844 melting Methods 0.000 claims description 9
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 238000000034 method Methods 0.000 claims description 8
- 238000009792 diffusion process Methods 0.000 claims description 7
- 238000009849 vacuum degassing Methods 0.000 claims description 4
- 238000007670 refining Methods 0.000 claims description 3
- 238000005496 tempering Methods 0.000 abstract description 12
- 229910001315 Tool steel Inorganic materials 0.000 abstract description 7
- 239000000126 substance Substances 0.000 abstract description 4
- 229910052804 chromium Inorganic materials 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 abstract 3
- 230000001276 controlling effect Effects 0.000 abstract 1
- 239000000463 material Substances 0.000 description 21
- 238000012360 testing method Methods 0.000 description 16
- 230000000694 effects Effects 0.000 description 11
- 238000007711 solidification Methods 0.000 description 5
- 230000008023 solidification Effects 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 238000009826 distribution Methods 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000005452 bending Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052755 nonmetal Inorganic materials 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、各種ねじ、スプライン軸、セレーション軸な
どの転造に用いる転造ダイス用工具鋼に関するものであ
る。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tool steel for rolling dies used for rolling various screws, spline shafts, serration shafts, and the like.
転造による加工は、従来ねじ製造に主に用いられてきた
が、転造機構の改良や、高精度化に伴い、自動車部品の
スプライン軸やセレーション軸の製造にも適用されてき
ている。転造ダイスの材質は、一部転造条件が過酷な場
合には、高速度工具鋼も用いられることはあるが、主に
５ＫＤＩＩを基本として、合金元素の添加などにより改
良を行なった冷間工具鋼が用いられている。Processing by rolling has traditionally been mainly used for manufacturing screws, but with improvements in rolling mechanisms and higher precision, it has also been applied to the manufacturing of spline shafts and serrated shafts for automobile parts. The material for rolling dies is mainly cold-rolled 5KDII, which has been improved by adding alloying elements, although high-speed tool steel is sometimes used when the rolling conditions are severe. Tool steel is used.
転造製品の適用課題に伴い、これらの素材、つまり被加
工材の材質も多様になってきている。自動車部品等にお
いては、硬さＨＲＣ４０前後の調質材を転造する場合も
現われてきている。また、雅加工材であるステンレスの
転造も増加してきている。Along with the application issues of rolled products, the materials used for these materials, that is, the materials to be processed, are also becoming more diverse. In automobile parts and the like, cases are emerging in which tempered materials with a hardness of around HRC40 are rolled. In addition, rolling of stainless steel, which is an elegant processed material, is increasing.
このような状況のもとで、転造ダイスの使用条件は過酷
になってきており、従来の転造ダイス材では、山部の欠
損や摩耗により十分な工具寿命を維持することが難しく
なってきている。このため、転造ダイスの廃却原因を詳
しく調査した結果、残留炭化物の性状が工具寿命を左右
する主因であることがわかった。つまり従来材は、耐摩
耗性を重視するあまり、Ｍ７Ｃ３型やＭＣ型の３０μｍ
以上の大型の１次炭化物を１０数％から数１０％と多量
に分布させた組織としていたが、欠損や摩耗はこれら大
型の１次炭化物の連鎖状分布を径路としてクラックが進
展するか、炭化物単位の欠落による微小欠損の集積が原
因であり、過剰の１次炭化物が逆効果として作用してい
たのである。また、従来鋼は、高温焼もどしでは十分な
硬さが得られないため、低温焼もどしにより使用されて
いたが、難加工材の転造では、かなりの昇温かあるため
、高温焼もどしにおいても十分な硬さの確保ができ、軟
化抵抗の高い材質が求められている。Under these circumstances, the operating conditions for rolling dies have become harsher, and with conventional rolling die materials, it has become difficult to maintain sufficient tool life due to chipping and wear of the ridges. ing. For this reason, a detailed investigation into the causes of scrapping of rolling dies revealed that the properties of residual carbide are the main factor that affects tool life. In other words, conventional materials place too much emphasis on wear resistance, so the M7C3 type and MC type 30 μm
The structure had large amounts of large primary carbides distributed in the range of 10-odds to several tens of percent, but defects and wear occur when cracks develop through the chain-like distribution of these large primary carbides, or when carbides The cause was the accumulation of microscopic defects due to missing units, and the excess primary carbide had the opposite effect. In addition, conventional steels were used by low-temperature tempering because high-temperature tempering did not provide sufficient hardness. There is a need for materials that can ensure sufficient hardness and have high softening resistance.
本発明は、これらの事実をもとになされたものであり、
化学成分の適正化とミクロ組織の調整により、１次炭化
物の適量化を図り、靭性を重視した材質とし、高温焼も
どしにおいてもＩ（ＲＣ６２以上の硬さの得られる高性
能転造ダイス材を提供するものである。さらに転造ダイ
スの微小クラックの原因となり易い硫化物系の非金属介
在物を最少限にとどめるため、Ｓ含有量を炭化物の面積
率とともに規制することが有効なこと、およびＰ含有量
もある特定値以下にすると、−段と靭性が向上し転造ダ
イスの欠は防止に有効であることを見出したものである
。The present invention was made based on these facts,
By optimizing the chemical composition and adjusting the microstructure, we have created a material with an emphasis on toughness by optimizing the amount of primary carbides and creating a high-performance rolling die material that can achieve a hardness of I (RC62 or higher) even when tempered at high temperatures. Furthermore, in order to minimize sulfide-based nonmetallic inclusions that tend to cause microcracks in rolling dies, it is effective to regulate the S content together with the area ratio of carbides; It has been discovered that when the P content is lower than a certain value, the toughness improves significantly and chipping of the rolling die is effectively prevented.
本発明は、重量％でＣｏ，９０〜１．３５％、 Ｓｉ
０．７０〜１．４０％、Ｍｎ１．０％以下、Ｓ ０．０
０４％以下７Ｃｒ ６．０−１０．０％、ＭｏとＷの１
種または２種をＭ ｏ ＋ Ｗ ／ ２で１．５〜２．
５％、■とＮｂの １種または２種をＶ ＋ Ｎｂ／２
で０．１５〜２．５％を含み、残部Ｆｅおよび不可避的
不純物からなり、さらに焼入れ焼もどし組織において、
Ｍ７Ｃ３型炭化物の面積率を２％以上９以下、ＭＣ炭化
物の面積率を２．５％以下としたことを特徴とする転造
ダイス用鋼、および重量％でＣｏ，９０〜１．３５％。The present invention comprises Co, 90-1.35%, Si
0.70-1.40%, Mn 1.0% or less, S 0.0
04% or less 7Cr 6.0-10.0%, Mo and W 1
Seed or two at M o + W/2 at 1.5-2.
5%, V + Nb/2 with one or two of ■ and Nb
0.15 to 2.5%, and the remainder consists of Fe and unavoidable impurities;
Steel for rolling dies, characterized in that the area ratio of M7C3 type carbides is 2% or more and 9 or less, and the area ratio of MC carbides is 2.5% or less, and Co, 90 to 1.35% by weight.
Ｓ ｉ ０．７０〜１．４０％、 Ｍｎ １．０％以下
、Ｓ ０．００４％以下、Ｃｒ ６．０−１０．０％、
ＭｏとＷの１種または２種をＭ。Si 0.70-1.40%, Mn 1.0% or less, S 0.004% or less, Cr 6.0-10.0%,
M contains one or two of Mo and W.
＋Ｗ／ｌ’１．５〜２．５％、ＶとＮｂの １種または
２種をＶ＋Ｎｂ／２で０．１５〜２．５％、ＮｉとＧｏ
の１種または２種をＮｉ＋Ｃｏで０．３〜１．５％を含
み、残部Ｆｅおよび不可避的不純物からなり、さらに焼
入れ焼もどし組織において、Ｍ７Ｃ３型炭化物の面積率
を２％以上９％以下、ＭＣ炭化物の面積率を２．５％以
下としたことを特徴とする転造ダイス用鋼、および重量
％でＣｏ，９０〜１．３５％、Ｓｉ ０．７０−１．４
０％、Ｍｎ１．０％以下、Ｓ ０．００４％以下、Ｐ
０．０１５％以下７Ｃｒ ６．０−１０．０％、Ｍｏと
Ｗの１種または２種をＭ ｏ ＋ Ｗ ／ ２で１．５
〜２．５％、■とＮｂ（７１１種または２種をＶ ＋
Ｎｂ／２テ０．１５〜２．５％を含み、残部Ｆｅおよび
不可避的不純物からなり、さらに焼入れ焼もどし組織に
おいて、Ｍ７Ｃ３型炭化物の面積率を２％以上的以下、
ＭＣ炭化物の面積率を２．５％以下としたことを特徴と
する転造ダイス用鋼、および重量％でＣｏ，９０〜１．
３５％、Ｓｉ０．７０〜１．４０％、 Ｍｎ １．０％
以下、Ｓ ０．００４％以下、Ｐ ０．０１５Ｘ以下７
Ｃｒ ６．０％、ＭｏとＷの１種または２種をＭ ｏ
＋ Ｗ ／ ２で１．５〜２．５％、ＶとＮｂの１種ま
たは２種をＶ＋Ｎｂ／２で０．１５〜２．５％、Ｎｉと
Ｇｏの１種または２種をＮｉ＋Ｃｏで０．３〜１．５％
を含み、残部Ｆｅおよび不可避的不純物からなり、さら
に焼入れ焼もどし組織において、Ｍ２Ｃ，型炭化物の面
積率を２％以上９％以下、ＭＣ炭化物の面積率を２．５
％以下としたことを特徴とする転造ダイス用鋼、および
真空溶解、真空脱ガスおよびエレクトロスラグ溶解から
選ばれる１種または２種以上の精錬方法により鋼塊を製
造する工程、該鋼塊または該鋼塊を熱間加工する過程で
、少なくとも一回以上１１５０〜１２５０℃で保持し、
高温拡散処理する工程を含む請求項１ないし４のいずれ
かに記載の転造ダイス用鋼の製造法である。+W/l'1.5-2.5%, one or two of V and Nb with V+Nb/2 0.15-2.5%, Ni and Go
1 or 2 of Ni+Co containing 0.3 to 1.5%, the remainder consisting of Fe and unavoidable impurities, and furthermore, in the quenched and tempered structure, the area ratio of M7C3 type carbide is 2% to 9%, A steel for rolling dies characterized by having an area ratio of MC carbides of 2.5% or less, and a weight% of Co, 90 to 1.35%, Si 0.70 to 1.4
0%, Mn 1.0% or less, S 0.004% or less, P
0.015% or less 7Cr 6.0-10.0%, one or two of Mo and W at Mo + W/2 1.5
~2.5%, ■ and Nb (711 species or 2 species V +
Contains 0.15 to 2.5% of Nb/2 Te, with the balance consisting of Fe and unavoidable impurities, and furthermore, in the quenched and tempered structure, the area ratio of M7C3 type carbides is 2% or more or less,
Steel for rolling dies, characterized in that the area ratio of MC carbides is 2.5% or less, and Co, 90 to 1.5% by weight.
35%, Si0.70-1.40%, Mn 1.0%
Below, S 0.004% or less, P 0.015X or less7
Cr 6.0%, one or two of Mo and W
+ 1.5-2.5% for W/2, 0.15-2.5% for V+Nb/2 for one or two of V and Nb, 0 for Ni+Co for one or two of Ni and Go .3-1.5%
The remainder consists of Fe and unavoidable impurities, and in the quenched and tempered structure, the area ratio of M2C type carbide is 2% to 9%, and the area ratio of MC carbide is 2.5.
% or less, and a process of producing a steel ingot by one or more refining methods selected from vacuum melting, vacuum degassing and electroslag melting, the steel ingot or In the process of hot working the steel ingot, holding it at 1150 to 1250°C at least once,
5. The method for producing steel for rolling dies according to claim 1, which includes a step of high temperature diffusion treatment.
以下に、化学成分の限定理由について述べる。The reason for limiting the chemical components will be described below.
Ｃは、工具鋼の強度、耐摩耗性の主因をなす元素であり
、十分な熱処理硬さを得るためには０．９％以上必要で
ある。またＣは７Ｃｒ、Ｍｏ、■と炭化物を形成し、耐
摩耗性に寄与する。しかし過剰になると、凝固時の１次
炭化物が多くなり、靭性を劣化させる原因となるため、
上限を１．３５％とした。C is an element that is the main cause of the strength and wear resistance of tool steel, and is required in an amount of 0.9% or more in order to obtain sufficient heat treatment hardness. Further, C forms a carbide with 7Cr, Mo, and ■, contributing to wear resistance. However, if it becomes excessive, the amount of primary carbide increases during solidification, which causes deterioration of toughness.
The upper limit was set at 1.35%.
Ｓｉは通常脱酸剤として添加されるが、本発明において
は、低温焼もどしく１８０〜２５０℃）において使用さ
れる場合も想定し、この温度域で軟化抵抗を発現するた
め規定した。この効果を十分に発揮するためには、少な
くとも０．７０％以上が必要であるが、１．４０％を越
えると靭性が低下してくるため、これを上限とした。Si is usually added as a deoxidizing agent, but in the present invention, it is also assumed that it will be used in low-temperature tempering (180 to 250°C), and is specified in order to exhibit softening resistance in this temperature range. In order to fully exhibit this effect, at least 0.70% or more is required, but if it exceeds 1.40%, the toughness decreases, so this was set as the upper limit.
Ｃｒは、凝固時にＭ７Ｃ，型炭化物として晶出する。こ
れは工具鋼の耐摩耗性を発揮する主因となるものである
が、その量は材質の靭性を大きく左右する。このため７
Ｃ量とのバランスから工具鋼としての耐摩耗性を維持す
るためには、６．０％以上必要であり、１０％を越える
と１次炭化物が過量となり、靭性が劣化してくるためこ
れを上限とした。Cr crystallizes as M7C type carbide during solidification. This is the main cause of the wear resistance of tool steel, and its amount greatly influences the toughness of the material. For this reason 7
In order to maintain the wear resistance as a tool steel from the balance with the C content, it is necessary to have a content of 6.0% or more, and if it exceeds 10%, the primary carbide becomes excessive and the toughness deteriorates. The upper limit was set.
ＭｏｌＷは７Ｃｒ炭化物に固溶して耐摩耗性を高めると
ともに、焼入性を向上させ、また焼もどしにおいて、炭
化物として析出し、強い２次硬化を示す元素である。転
造ダイスでは被加工材の種類、特に難加工材では加工中
に昇温するため、ダイスには高温焼もどしが必要になる
場合がある。したがって、高温焼もどしによる硬さと）
ｌＲｃ６２以上と設定しＭｏ、Ｗ量を規定した。MolW is an element that solidly dissolves in 7Cr carbide to improve wear resistance and hardenability, and precipitates as a carbide during tempering and exhibits strong secondary hardening. With rolling dies, the temperature of the type of workpiece material, especially difficult-to-work materials, increases during processing, so the die may require high-temperature tempering. Therefore, the hardness due to high temperature tempering)
The Mo and W amounts were defined by setting lRc62 or more.
Ｍｏは、靭性の改善にＷは耐摩耗性の向上にそれぞれ有
効であるため、用途により使い分けを行なうこととし、
Ｗの原子量はＭｏの約２倍であるため、（Ｍｏ＋Ｗ／２
）としてまとめ硬さの設定から１．５〜２．５％とした
。Mo is effective in improving toughness and W is effective in improving wear resistance, so they are used differently depending on the application.
Since the atomic weight of W is approximately twice that of Mo, (Mo+W/2
) was set at 1.5 to 2.5% based on the hardness setting.
■、Ｎｂはともに凝固時にＭＣ型炭化物として晶出する
ものであり、硬質の炭化物として耐摩耗性に重要な役割
を担うとともに、結晶粒微細化の効果があり、靭性の向
上に有効である。また２次硬化元素であるため、高温焼
もどしによる硬さ確保に有利である。これら効果を発揮
するためには、ＶとＮｂの １種または２種を（Ｖ ＋
Ｎ ｂ／２） テ少なくとも０．１５％以上必要であ
る。しかし、この型の炭化物は多量にな゛ると連鎖状に
分布し、分布方向の靭性を劣化させるだけでなく、熱処
理によってほとんど変化しない。このため後に述べるＭ
Ｃ型炭化物量の規定から上限を２．５％とした。(2) and Nb both crystallize as MC type carbides during solidification, and as hard carbides they play an important role in wear resistance, have the effect of grain refinement, and are effective in improving toughness. Furthermore, since it is a secondary hardening element, it is advantageous in ensuring hardness through high temperature tempering. In order to exhibit these effects, one or both of V and Nb (V +
Nb/2) must be at least 0.15%. However, when this type of carbide is present in a large amount, it is distributed in a chain pattern, which not only deteriorates the toughness in the distribution direction, but also hardly changes by heat treatment. For this reason, M
Based on the regulations for the amount of C-type carbide, the upper limit was set at 2.5%.
Ｎｕ７Ｃｏはともに基地に固溶して靭性や焼付性を改善
する効果がある。またＮｉは焼入性の向上にも寄与する
。このためには、ＮｉとＣｏの１種または２種を（Ｎｉ
＋Ｃｏ）で少なくとも０．３％以上必要であるが、過剰
の添加はともに熱処理硬さを低下させるため上限を１．
５％とした。Both Nu7Co are solid-solved in the matrix and have the effect of improving toughness and seizability. Ni also contributes to improving hardenability. For this purpose, one or both of Ni and Co (Ni
+Co) is required to be at least 0.3%, but excessive addition will reduce heat treatment hardness, so the upper limit should be set at 1.3%.
It was set at 5%.
Ｍｎは通常脱酸剤として添加されるが、１％を越えると
熱間加工性を害するだけでなく、被剛性を劣化させるた
めこれを上限とした。Ｓは特にＭｎと非金属介在物（Ｍ
ｎＳ）を形成し、圧延方向に伸びた状態で分布する傾向
を持つ。この場合、特に圧延方向の靭性が低下する。転
造ダイスにおいては、刃部の圧造方向にこの非金属介在
物が並ぶと、刃の欠損につながるためできるだけ低Ｓと
することが望まれる。この点について検討したところ、
０．００４％以下のＳにおいて、改善効果が見られたの
でこれを上限とした。Mn is usually added as a deoxidizing agent, but if it exceeds 1%, it not only impairs hot workability but also deteriorates stiffness, so this was set as the upper limit. S is especially suitable for Mn and nonmetallic inclusions (M
nS) and tends to be distributed in an elongated state in the rolling direction. In this case, the toughness particularly in the rolling direction is reduced. In a rolling die, if these non-metallic inclusions are lined up in the heading direction of the blade, it will lead to chipping of the blade, so it is desirable to have S as low as possible. After considering this point,
Since an improvement effect was seen at S of 0.004% or less, this was set as the upper limit.
Ｐは、転造ダイスの刃部に作用する衝撃力に耐えるため
に低い方がよい。特に０．０１５％以下にすると衝撃値
の縦横の異方性を小さくできるために転造ダイスの寿命
向上に寄与する。It is better for P to be low in order to withstand the impact force acting on the blade of the rolling die. In particular, when the content is 0.015% or less, the longitudinal and lateral anisotropy of the impact value can be reduced, which contributes to improving the life of the rolling die.
前述したように、転造ダイス材の寿命を左右するのは、
凝固時に晶出する１次炭化物である。したがって、本発
明の効果を十分発揮するためには本発明の成分範囲にお
いて、さらに１次炭化物の量を規定する必要がある。従
来の５ＫＤ１ルベルでは、Ｍ７Ｃ３型の１次炭化物の面
積率は、１０〜１２％であった。Ｍ７Ｃ，型１次炭化物
を種々の面積率を示す材質について靭性との関連を調査
したところ、９％以下において改善効果が見られるため
、これを上限とした。しかし工具としての耐摩耗性も必
要であり、完全になくすことはできない、耐摩耗性の面
からは少なくとも２％以上必要である。As mentioned above, the lifespan of rolling die material is influenced by:
It is a primary carbide that crystallizes during solidification. Therefore, in order to fully exhibit the effects of the present invention, it is necessary to further specify the amount of primary carbide in the component range of the present invention. In the conventional 5KD1 rubel, the area ratio of M7C3 type primary carbide was 10 to 12%. When we investigated the relationship between M7C and type primary carbide and toughness for materials showing various area ratios, an improvement effect was seen at 9% or less, so this was set as the upper limit. However, wear resistance as a tool is also necessary, and it cannot be completely eliminated.From the viewpoint of wear resistance, at least 2% or more is required.
ＭＣ型炭化物は、耐摩耗性に大きな効果があるだけでな
く、凝固時にＭ７Ｃ３型炭化物に先立って晶出し、Ｍ７
Ｃ，型炭化物の分布状態を改善する効果もある。しかし
、面積率で２．５％を越えると靭性が低下してくるため
、これを上限とした。MC type carbide not only has a great effect on wear resistance, but also crystallizes out before M7C3 type carbide during solidification, resulting in M7
It also has the effect of improving the distribution state of C, type carbides. However, if the area ratio exceeds 2.5%, the toughness decreases, so this was set as the upper limit.
本発明鋼を製造するには、Ｓ、Ｐなどの不純物を低め、
非金属を最少限に調整して靭性の向上を図るために真空
溶解、真空脱ガスおよびエレクトロスラグ溶解から選ば
れる１種または２種以上の精錬方法を適用することが望
ましい。さらに上述のＭ７Ｃ，型およびＭＣ型の１次炭
化物量を調整する手段として、本発明鋼の製造するに当
って鋼塊または鋼塊を熱間加工する過程で、少なくとも
１回以上１１５０〜１２５０℃で保持し高温拡散処理す
る工程を含むことが望ましい。拡散温度は１１５０℃未
満だと十分な元素の拡散、均質化が行なわれないため、
下限を１１５０℃とし、１２５０℃を越えると一部炭化
物が溶融し、機械的強度を下げるため上限を１２５０℃
とした。In order to manufacture the steel of the present invention, impurities such as S and P must be reduced,
In order to improve toughness by minimizing nonmetal content, it is desirable to apply one or more refining methods selected from vacuum melting, vacuum degassing, and electroslag melting. Furthermore, as a means of adjusting the amount of primary carbides in the above-mentioned M7C, type and MC type, in the process of hot working a steel ingot or steel ingot in manufacturing the steel of the present invention, at least once at a temperature of 1150 to 1250°C. It is desirable to include a step of holding at a high temperature and performing a high-temperature diffusion treatment. If the diffusion temperature is less than 1150℃, sufficient diffusion and homogenization of elements will not occur.
The lower limit is set at 1150°C, and if the temperature exceeds 1250°C, some of the carbide will melt, reducing mechanical strength, so the upper limit is set at 1250°C.
And so.
以下、本発明を実施例に基づいて説明する。第１表は本
発明鋼を評価するために従来鋼および比較鋼とともに製
造した本発明鋼の化学成分を示すものである。供試鋼Ｎ
ｏのうち、Ｎ ｏ 、 １が従来鋼であり、Ｎ０９２は
Ｐ、Ｓ以外は本発明の成分範囲内にあるが、Ｍ□Ｏ１型
Ｏ１物の多いもの、Ｎｏ、３は成分は本発明鋼と同一で
あるが、Ｍ７Ｃ，型炭化物が本発明鋼より多いものであ
る。供試鋼Ｎｏ、１とＮ００２については高周波溶解、
供試鋼Ｎｏ、３ないしＮｏ、７については真空誘導溶解
、供試鋼Ｎｏ、８とＮｏ、９についてはＥＳＲ溶解、お
よび供試鋼Ｎｏ。Hereinafter, the present invention will be explained based on examples. Table 1 shows the chemical composition of the inventive steel produced together with conventional steel and comparative steel in order to evaluate the inventive steel. Test steel N
Among o, No. 1 is conventional steel, No. 092 is within the composition range of the present invention except for P and S, but M□O1 type has a large amount of O1, and No. 3 has the composition of the steel of the present invention. , but has more M7C type carbides than the steel of the present invention. For test steel No. 1 and No. 002, high frequency melting,
Test steel No. 3 to No. 7 was vacuum induction melted, test steel No. 8 and No. 9 were ESR melting, and test steel No.
１０ないしＮｏ、１２については、真空脱ガス処理を行
なったものである。供試鋼Ｎｏ、４ないしＮｏ、１２の
本発明鋼の鋼塊については、１次炭化物、特にＭ７Ｃ，
型炭化物を調整するために、１１７０℃で２０時間保持
する高温拡散処理を行なった。Samples No. 10 to No. 12 were subjected to vacuum degassing treatment. Regarding the steel ingots of test steel No. 4 to No. 12 of the present invention steel, primary carbides, especially M7C,
In order to adjust the type carbide, a high temperature diffusion treatment was performed at 1170° C. for 20 hours.
この高温拡散処理の条件は、１次炭化物が溶融しない範
囲でできるだけ高い温度が望ましいので、温度としては
１１５０〜１２５０℃の範囲が最適である。The conditions for this high-temperature diffusion treatment are preferably as high as possible without melting the primary carbide, so the temperature is optimally in the range of 1150 to 1250°C.
すべての鋼塊は鍛造圧延により、断面寸法が１０１００
ｍｍＸ１００の鋼片とした。この鋼片に焼なまし処理を
行ない供試材とした。All steel ingots are forged rolled and have a cross-sectional dimension of 10100.
A steel piece of mm×100 was used. This steel piece was annealed and used as a test material.
抗折試験片は、鋼片の圧延方向（以下り方向という）と
圧延方向に直角な方向（以下Ｔ方向という）よりφ５Ｘ
７０ｎｍ＋２の試験片を採取し、所定の焼入れ焼もどし
を行ない試験に供した。なお、焼もどしは供試鋼Ｎ ｏ
、 ｌは低温焼もどし、他は二次硬化を示す範囲での
高温焼もどしである。抗折試験は２点支持で、支点間隔
５０ｍｍで行ない、ミクロ組織の炭化物の定量はＬ方向
とＴ方向の試料の平均値として表わした。これらの結果
を第２表にまとめて示す。The bending test piece was φ5
A 70 nm+2 test piece was taken, subjected to predetermined quenching and tempering, and then used for testing. In addition, the tempering was performed on the test steel No.
, l is low-temperature tempering, and the others are high-temperature tempering in a range that indicates secondary hardening. The bending test was carried out using two-point support with a supporting point spacing of 50 mm, and the amount of carbide in the microstructure was expressed as the average value of the samples in the L direction and the T direction. These results are summarized in Table 2.
本発明鋼は、ＨＲＣ６２以上の高い硬さが得られるとと
もに一次炭化物の調整により、従来材に比較して高い抗
折力と大きなたわみが得られ、靭性の優れた材質である
ことがわかる。It can be seen that the steel of the present invention has a high hardness of HRC 62 or higher, and by adjusting the primary carbide, a higher transverse rupture strength and greater deflection than conventional materials can be obtained, and it is a material with excellent toughness.
また、本発明鋼と類似する比較鋼でも、−次炭化物の多
いものは抗折力が小さいこと、およびＰ、Ｓの不純物の
少ない供試ｔｌＮｏ、４ないしＮｏ、１２の抗折力のＬ
／Ｔの比は、不純物の多い供試鋼Ｎ００１、Ｎｏ、２に
比較して大きく、本発明鋼の靭性値の縦横の差異が小さ
いことがわかる。In addition, even among comparative steels similar to the steel of the present invention, those with a large amount of primary carbides have a small transverse rupture strength, and the transverse rupture strength of the sample tl No. 4 to No. 12 with a small amount of P and S impurities is L.
It can be seen that the ratio of /T is larger than that of test steels No. 001, No. 2, which contain many impurities, and the vertical and horizontal differences in toughness values of the steel of the present invention are small.
また耐摩耗性について、大館式摩耗試験を行なった結果
を同時に示した。これは相手材を５ＫＤ６１ （）ｌＲ
ｃ４０）とし、摩擦速度１．３７ｍ／ｓ、摩擦距離４０
０ｍ、最終荷重６．３ｋｇの条件で試験を行ない、摩耗
体積を測定し、従来鋼の摩耗体積を１００とした場合の
指数である。比較鋼はＭ７Ｃ，型炭化物およびＭＣ型炭
化物量が多く耐摩耗性に優れているが靭性で劣る１本発
明鋼は靭性を重視した材質であるが、耐摩耗性において
も従来鋼と遜色なく、またＭＣ型炭化物の多い供試鋼Ｎ
０１６、Ｎｏ、１２では従来鋼より優れていることがわ
かる。In addition, regarding wear resistance, the results of an Odate type wear test were also shown. This is the mating material 5KD61 ()lR
c40), friction speed 1.37 m/s, friction distance 40
The test was conducted under the conditions of 0 m and a final load of 6.3 kg, and the wear volume was measured, and the index is based on the wear volume of conventional steel being set as 100. The comparison steel has a large amount of M7C type carbide and MC type carbide, and has excellent wear resistance, but is inferior in toughness.1 Although the steel of the present invention is a material that emphasizes toughness, it is comparable to conventional steel in terms of wear resistance. In addition, test steel N with many MC type carbides
It can be seen that samples No. 016, No. 12 are superior to conventional steels.
比較のため゛に供試１ｉＮｏ、１とＮｏ、５のミクロ組
織を第１図に示す。For comparison, the microstructures of samples 1iNo. 1 and No. 5 are shown in FIG.
本発明は、従来の転造ダイスの廃却原因の解析に基づき
なされたものであり、１次炭化物を適正化することによ
り、高硬度でしかも高い靭性を有する転造ダイス用鋼を
開発したものである。本発明により、過酷な転造条件に
おいても、長寿命を有する転造ダイスを製造することが
できる。The present invention was made based on an analysis of the causes of scrapping of conventional rolling dies, and developed a steel for rolling dies that has high hardness and high toughness by optimizing the primary carbide content. It is. According to the present invention, it is possible to manufacture a rolling die that has a long life even under severe rolling conditions.
Claims (1)
１．４０％、Ｍｎ１．０％以下、Ｓ０．００４％以下、
Ｃｒ６．０〜１０．０％、ＭｏとＷの１種または２種を
Ｍｏ＋Ｗ／２で１．５〜２．５％、ＶとＮｂの１種また
は２種をＶ＋Ｎｂ／２で０．１５〜２．５％を含み、残
部Ｆｅおよび不可避的不純物からなり、さらに焼入れ焼
もどし組織において、Ｍ＿７Ｃ＿３型炭化物の面積率を
２％以上９％以下、ＭＣ炭化物の面積率を２．５％以下
としたことを特徴とする転造ダイス用鋼。 ２ 重量％でＣ０．９０〜１．３５％、Ｓｉ０．７０〜
１．４０％、Ｍｎ１．０％以下、Ｓ０．００４％以下、
Ｃｒ６．０〜１０．０％、ＭｏとＷの１種または２種を
Ｍｏ＋Ｗ／２で１．５〜２．５％、ＶとＮｂの１種また
は２種をＶ＋Ｎｂ／２で０．１５〜２．５％、ＮｉとＣ
ｏの１種または２種をＮｉ＋Ｃｏで０．３〜１．５％を
含み、残部Ｆｅおよび不可避的不純物からなり、さらに
焼入れ焼もどし組織において、Ｍ＿７Ｃ＿３型炭化物の
面積率を２％以上９％以下、ＭＣ炭化物の面積率を２．
５％以下としたことを特徴とする転造ダイス用鋼。 ３ 重量％でＣ０．９０〜１．３５％、Ｓｉ０．７０〜
１．４０％、Ｍｎ１．０％以下、Ｓ０．００４％以下、
Ｐ０．０１５％以下、Ｃｒ６．０〜１０．０％、Ｍｏと
Ｗの１種または２種をＭｏ＋Ｗ／２で１．５〜２．５％
、ＶとＮｂの１種または２種をＶ＋Ｎｂ／２で０．１５
〜２．５％を含み、残部Ｆｅおよび不可避的不純物から
なり、さらに焼入れ焼もどし組織において、Ｍ＿７Ｃ＿
３型炭化物の面積率を２％以上９％以下、ＭＣ炭化物の
面積率を２．５％以下としたことを特徴とする転造ダイ
ス用鋼。 ４ 重量％でＣ０．９０〜１．３５％、Ｓｉ０．７０〜
１．４０％、Ｍｎ１．０％以下、Ｓ０．００４％以下、
Ｐ０．０１５％以下、Ｃｒ６．０〜１０．０％、Ｍｏと
Ｗの１種または２種をＭｏ＋Ｗ／２で１．５〜２．５％
、ＶとＮｂの１種または２種をＶ＋Ｎｂ／２で０．１５
〜２．５％、ＮｉとＣｏの１種または２種をＮｉ＋Ｃｏ
で０．３〜１．５％を含み、残部Ｆｅおよび不可避的不
純物からなり、さらに焼入れ焼もどし組織において、Ｍ
＿７Ｃ＿３型炭化物の面積率を２％以上９％以下、ＭＣ
炭化物の面積率を２．５％以下としたことを特徴とする
転造ダイス用鋼。 ５ 真空溶解、真空脱ガスおよびエレクトロスラグ溶解
から選ばれる１種または２種以上の精錬方法により鋼塊
を製造する工程、該鋼塊または該鋼塊を熱間加工する過
程で、少なくとも一回以上１１５０〜１２５０℃で保持
し、高温拡散処理する工程を含む請求項１ないし４のい
ずれかに記載の転造ダイス用鋼の製造法。[Claims] 1% by weight: C0.90~1.35%, Si0.70~
1.40%, Mn 1.0% or less, S 0.004% or less,
Cr6.0-10.0%, one or two of Mo and W in Mo+W/2 1.5-2.5%, one or two of V and Nb in V+Nb/2 0.15-2.5% 2.5%, with the balance consisting of Fe and unavoidable impurities, and furthermore, in the quenched and tempered structure, the area ratio of M_7C_3 type carbide was 2% to 9%, and the area ratio of MC carbide was 2.5% or less. A steel for rolling dies characterized by: 2% by weight: C0.90~1.35%, Si0.70~
1.40%, Mn 1.0% or less, S 0.004% or less,
Cr6.0-10.0%, one or two of Mo and W in Mo+W/2 1.5-2.5%, one or two of V and Nb in V+Nb/2 0.15-2.5% 2.5%, Ni and C
Contains 0.3 to 1.5% of one or two types of o in Ni + Co, the balance consists of Fe and unavoidable impurities, and furthermore, in the quenched and tempered structure, the area ratio of M_7C_3 type carbide is 2% or more and 9% or less , the area ratio of MC carbide is 2.
Steel for rolling dies characterized by having a content of 5% or less. 3 C0.90~1.35% by weight, Si0.70~
1.40%, Mn 1.0% or less, S 0.004% or less,
P0.015% or less, Cr6.0-10.0%, one or both of Mo and W in Mo+W/2 1.5-2.5%
, one or both of V and Nb at V+Nb/2 = 0.15
~2.5%, the balance consists of Fe and unavoidable impurities, and in the quenched and tempered structure, M_7C_
A steel for rolling dies, characterized in that the area ratio of type 3 carbide is 2% or more and 9% or less, and the area ratio of MC carbide is 2.5% or less. 4 C0.90~1.35%, Si0.70~ by weight%
1.40%, Mn 1.0% or less, S 0.004% or less,
P0.015% or less, Cr6.0-10.0%, one or both of Mo and W in Mo+W/2 1.5-2.5%
, one or both of V and Nb at V+Nb/2 = 0.15
~2.5%, one or both of Ni and Co added to Ni+Co
The balance consists of Fe and unavoidable impurities, and in the quenched and tempered structure, M
_7C_3 type carbide area ratio from 2% to 9%, MC
Steel for rolling dies, characterized in that the area ratio of carbides is 2.5% or less. 5 At least once in the process of manufacturing a steel ingot by one or more refining methods selected from vacuum melting, vacuum degassing, and electroslag melting, and in the process of hot working the steel ingot or the steel ingot. The method for producing steel for rolling dies according to any one of claims 1 to 4, comprising a step of holding at 1150 to 1250°C and performing a high-temperature diffusion treatment.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027162A JP2710941B2 (en) | 1988-02-08 | 1988-02-08 | Rolling die steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027162A JP2710941B2 (en) | 1988-02-08 | 1988-02-08 | Rolling die steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01201442A true JPH01201442A (en) | 1989-08-14 |
| JP2710941B2 JP2710941B2 (en) | 1998-02-10 |
Family
ID=12213362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63027162A Expired - Fee Related JP2710941B2 (en) | 1988-02-08 | 1988-02-08 | Rolling die steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2710941B2 (en) |
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| JPH0215146A (en) * | 1988-06-30 | 1990-01-18 | Aichi Steel Works Ltd | Cold tool steel |
| US6053991A (en) * | 1998-01-06 | 2000-04-25 | Sanyo Special Steel Co., Ltd. | Production of cold working tool steel |
| EP1024208A1 (en) * | 1999-01-28 | 2000-08-02 | Hitachi Metals Co. Ltd. | Blade material for metallic band saw and metallic band saw made therefrom |
| EP1905858A1 (en) * | 2006-09-29 | 2008-04-02 | Crucible Materials Corporation | Cold-work tool steel article |
| CN102644027A (en) * | 2011-02-22 | 2012-08-22 | 宝山钢铁股份有限公司 | Fixed-length shear blade and manufacturing method thereof |
| CN103692153A (en) * | 2013-09-17 | 2014-04-02 | 马鞍山市益华液压机具有限公司 | Manufacturing method of reaction arm |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102653837A (en) * | 2012-02-24 | 2012-09-05 | 宝山钢铁股份有限公司 | High-toughness wear-resistant cold-working die steel and preparation method thereof |
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| JPS59179762A (en) * | 1983-03-30 | 1984-10-12 | Daido Steel Co Ltd | Cold tool steel |
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| JPS5237511A (en) * | 1975-09-22 | 1977-03-23 | Hitachi Metals Ltd | Alloy tool steel for cold working |
| JPS59179762A (en) * | 1983-03-30 | 1984-10-12 | Daido Steel Co Ltd | Cold tool steel |
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Cited By (9)
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|---|---|---|---|---|
| JPH0215146A (en) * | 1988-06-30 | 1990-01-18 | Aichi Steel Works Ltd | Cold tool steel |
| US6053991A (en) * | 1998-01-06 | 2000-04-25 | Sanyo Special Steel Co., Ltd. | Production of cold working tool steel |
| EP1024208A1 (en) * | 1999-01-28 | 2000-08-02 | Hitachi Metals Co. Ltd. | Blade material for metallic band saw and metallic band saw made therefrom |
| US6272963B1 (en) | 1999-01-28 | 2001-08-14 | Hitachi Metals, Ltd. | Blade material for metallic band saw and metallic band saw made therefrom |
| CN1100892C (en) * | 1999-01-28 | 2003-02-05 | 日立金属株式会社 | Saw edge material for metal band saw and metal band saw manufactured therefrom |
| EP1905858A1 (en) * | 2006-09-29 | 2008-04-02 | Crucible Materials Corporation | Cold-work tool steel article |
| US7615123B2 (en) | 2006-09-29 | 2009-11-10 | Crucible Materials Corporation | Cold-work tool steel article |
| CN102644027A (en) * | 2011-02-22 | 2012-08-22 | 宝山钢铁股份有限公司 | Fixed-length shear blade and manufacturing method thereof |
| CN103692153A (en) * | 2013-09-17 | 2014-04-02 | 马鞍山市益华液压机具有限公司 | Manufacturing method of reaction arm |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2710941B2 (en) | 1998-02-10 |
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