JPH0243346A - Tool steel for hot working - Google Patents
Tool steel for hot workingInfo
- Publication number
- JPH0243346A JPH0243346A JP19419488A JP19419488A JPH0243346A JP H0243346 A JPH0243346 A JP H0243346A JP 19419488 A JP19419488 A JP 19419488A JP 19419488 A JP19419488 A JP 19419488A JP H0243346 A JPH0243346 A JP H0243346A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- less
- toughness
- hot working
- strength
- 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
- 229910001315 Tool steel Inorganic materials 0.000 title claims abstract description 8
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 9
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 9
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 9
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 8
- 239000012535 impurity Substances 0.000 claims abstract description 6
- 229910052710 silicon Inorganic materials 0.000 claims abstract 6
- 229910000717 Hot-working tool steel Inorganic materials 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 abstract description 56
- 239000010959 steel Substances 0.000 abstract description 56
- 239000000203 mixture Substances 0.000 abstract description 4
- 229910052799 carbon Inorganic materials 0.000 abstract description 3
- 238000005336 cracking Methods 0.000 abstract description 3
- 229910052759 nickel Inorganic materials 0.000 abstract description 3
- 229910052717 sulfur Inorganic materials 0.000 abstract description 3
- 229910052720 vanadium Inorganic materials 0.000 abstract description 3
- 229910052742 iron Inorganic materials 0.000 abstract description 2
- 238000005299 abrasion Methods 0.000 abstract 1
- 230000002035 prolonged effect Effects 0.000 abstract 1
- 230000000694 effects Effects 0.000 description 24
- 150000001247 metal acetylides Chemical class 0.000 description 16
- 239000000463 material Substances 0.000 description 12
- 238000009826 distribution Methods 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 6
- 238000005496 tempering Methods 0.000 description 6
- 238000001816 cooling Methods 0.000 description 5
- 238000010791 quenching Methods 0.000 description 5
- 230000000171 quenching effect Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 230000001681 protective effect Effects 0.000 description 4
- 230000009466 transformation Effects 0.000 description 4
- 238000005266 casting Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000004512 die casting Methods 0.000 description 3
- 238000005242 forging Methods 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 2
- 230000001070 adhesive effect Effects 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910001563 bainite Inorganic materials 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000005121 nitriding Methods 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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〕
本発明は常温強度、高温強度に優れ、かつ十分な焼入性
を備えており、実用上十分な靭性を備えていることを特
徴とする熱間加工用工具鋼に関するものである。さらに
詳しくは、近年のアルミダイカスト技術における鋳造合
金溶湯温度の上昇または、寸法精度向上のための熱間鍛
造型のシャープコーナー化など使用条件の過酷化に耐え
るための高温域の強度が優れ、かつ大割れを生ぜず長寿
命の金型に代表される熱間加工用工具鋼に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized by having excellent room temperature strength and high temperature strength, sufficient hardenability, and practically sufficient toughness. This relates to tool steel for hot working. More specifically, it has excellent strength in the high-temperature range to withstand harsher operating conditions, such as the rise in the temperature of the molten casting alloy in recent aluminum die-casting technology and the sharp corners of hot forging dies to improve dimensional accuracy. It relates to tool steel for hot working, typified by molds that do not cause large cracks and have a long life.
従来、アルミダイカスト型材としては、５ＫＤ６１が広
く使用されてきた。しかし近年、ダイカスト製品が複雑
形状化し、寸法精度、耐摩耗性も向上させたいという製
品からの要請に応じて、鋳造合金の溶湯温度を上昇させ
たり、成形圧力を高めるなど型材に負荷される応力が過
酷化している。Conventionally, 5KD61 has been widely used as an aluminum die-casting material. However, in recent years, die-cast products have become more complex in shape, and in response to product demands for improved dimensional accuracy and wear resistance, the stress applied to the mold material has been increased by increasing the temperature of the molten metal of the casting alloy and increasing the molding pressure. is becoming harsher.
このため、５ＫＤ６１では高温域での強度や軟化抵抗が
不足し、ヒートクラックが発生し易く早期に型寿命に至
るので、５ＫＤ６１での対応は困難であった。For this reason, 5KD61 lacks strength and softening resistance in high temperature ranges, tends to generate heat cracks, and reaches the end of its mold life early, so it has been difficult to deal with this problem with 5KD61.
また、熱間鋳造技術の分野でも、成形品の歩留向上のた
め、成形品の寸法精度の高い閉塞鍛造の技術が進み、金
型に対する負荷が増し、やはり５ＫＤ６１での対応は困
難である。Furthermore, in the field of hot casting technology, in order to improve the yield of molded products, the technology of closed forging with high dimensional accuracy of molded products has advanced, increasing the load on the mold, which is still difficult to handle with 5KD61.
これらの分野には、５ＫＤ６１より強度の優れた５ＫＤ
７．５ＫＤ８が使用されてきたが、焼入性の不足に伴う
靭性面や、鋼材の熱間加工方向に整列する炭化物の紐状
分布に沿う縦方向の耐割れ性に問題があった。For these fields, 5KD, which is stronger than 5KD61, is used.
7.5KD8 has been used, but there were problems in terms of toughness due to insufficient hardenability and cracking resistance in the longitudinal direction along the string-like distribution of carbides aligned in the hot working direction of the steel material.
これらの従来鋼５ＫＤ７．５ＫＤ８の問題点の改善につ
いて特公昭５６−５４３７９号、特開昭５４−５０４２
１号、特開昭６２−１４９８５２号等、種々提案がなさ
れ、一定の改善効果が得られているものの、未だ、型寿
命を十分満たしたものではなかった。これらの問題点は
主に高温下で強度、耐力および軟化抵抗が十分でないた
め、ヒートクラックが発生しやすいことにあった（具体
的には後述の実施例で示す）。Regarding improvement of these problems of conventional steel 5KD7.5KD8, Japanese Patent Publication No. 56-54379 and Japanese Patent Application Laid-Open No. 54-5042
Various proposals have been made, such as No. 1 and JP-A-62-149852, and although certain improvement effects have been obtained, they still do not fully satisfy the mold life. The main problem with these materials is that they do not have sufficient strength, yield strength, or softening resistance at high temperatures, and therefore heat cracks are likely to occur (specifically, as shown in Examples below).
本発明は従来鋼の問題点である高温強度、靭性を改善し
、かつ炭化物の紐状分布を少なくし、高温でのヒートク
ラックの発生伸展を抑え、かつクラックが熱間加工方向
へ伸展しにくい型材を提供しようとするものである。The present invention improves high temperature strength and toughness, which are problems of conventional steel, and reduces the string-like distribution of carbides, suppresses the occurrence and extension of heat cracks at high temperatures, and makes it difficult for cracks to extend in the hot working direction. The aim is to provide mold materials.
本発明鋼の化学組成は、炭化物形成元素の量、成分間の
バランスについて系統的な検討を行ない、高温強度、靭
性の両面がらの最適化をはかり、かつ素材の炭化物の紐
状分布の形成傾向を減じ、適量の炭化物を分散分布させ
ることから決定されたものである。The chemical composition of the steel of the present invention was determined by systematically examining the amount of carbide-forming elements and the balance between the components, aiming to optimize both high-temperature strength and toughness, and the tendency of the material to form a string-like distribution of carbides. It was determined by reducing the amount of carbide and dispersing the appropriate amount of carbide.
本発明鋼は、併せて、Ｎ添加による結晶粒の微細化効果
が、Ｎ１添加による基地の本質的な靭性改善とあいまっ
て、特に優れた靭性が付与されている。In addition, the steel of the present invention has particularly excellent toughness due to the effect of grain refinement due to the addition of N, combined with the essential toughness improvement of the matrix due to the addition of N1.
また、熱間での耐摩耗性付与のためにＧｏを添加し、使
用時の昇温により型表面に緻密で固着性の大きい酸化皮
膜を形成させ、これによる潤滑作用および断熱効果によ
り母材の強度、適量の炭化物分布とあいまって、温間お
よび熱間での耐摩耗性、耐肌あれ性を大幅に改善したも
のである。In addition, Go is added to provide wear resistance in hot conditions, and as the temperature rises during use, a dense and highly adhesive oxide film is formed on the mold surface.The lubrication and heat insulation effects of this create a bonding effect on the base material. Combined with strength and a suitable amount of carbide distribution, it has greatly improved wear resistance and roughening resistance in both warm and hot conditions.
すなわち本発明は、重量％でＣ０．３６〜０．５％。That is, in the present invention, C0.36 to 0.5% by weight.
Ｓｉ １．００％以下、Ｍｎ１．００％以下、Ｃｒ ２
．６０−４．００％、ＷとＭｏの１種または２種が１．
／２Ｗ＋Ｍｏで２．６０−３．５０％、 Ｖ ０．７１
〜１．５％、Ｎｉ １．２０％以下、Ｓ ０．００５２
以下、および場合によっては、Ｃｏ ０．５０〜５．０
０％。Si 1.00% or less, Mn 1.00% or less, Cr2
．． 60-4.00%, one or two of W and Mo are 1.
/2W+Mo 2.60-3.50%, V 0.71
~1.5%, Ni 1.20% or less, S 0.0052
Below, and in some cases, Co 0.50-5.0
0%.
Ｎ ０．１０％以下を適宜含有し、残部Ｆｅおよび不可
避的不純物からなることを特徴とする熱間加工用工具鋼
である。This is a hot working tool steel characterized by appropriately containing 0.10% or less of N, with the remainder consisting of Fe and unavoidable impurities.
次に本発明鋼の成分範囲の限定理由について述べる。 Next, the reason for limiting the composition range of the steel of the present invention will be described.
Ｃは、本発明鋼の優れた焼入性、焼もどし硬さ、および
高温硬さを維持し、またＷ、Ｍ０．■およびＣｒなどの
炭化物形成元素と結合して炭化物を形成し、結晶粒の微
細化、耐摩耗性、焼もどし軟化抵抗、高温硬さを与える
ために添加するものである。Ｃは多すぎると靭性を低下
させ、また紐状の炭化物分布を過度に生じさせるので０
．５０％以下とし、少なすぎると上記添加の効果が得ら
れないので、含有量を０．３６％以上とする。C maintains the excellent hardenability, tempering hardness, and high temperature hardness of the steel of the present invention, and W, M0. (2) It combines with carbide-forming elements such as Cr and Cr to form carbides, and is added to refine crystal grains, provide wear resistance, temper softening resistance, and high-temperature hardness. Too much C reduces toughness and causes excessive string-like carbide distribution, so 0
．． The content should be 50% or less, and if it is too small, the above-mentioned effect of addition cannot be obtained, so the content should be 0.36% or more.
Ｓｉは、Ａ３変態点を高めることと用途に応じた耐酸化
性を付与するために添加されるが、過剰の添加は、使用
中の昇温による保護性酸化皮膜を形成させに＜＜シ、ま
た靭性、熱伝導性を低下させるので１．００％以下とす
る。Si is added to raise the A3 transformation point and provide oxidation resistance depending on the application, but excessive addition may cause the formation of a protective oxide film due to temperature rise during use. Further, since it lowers toughness and thermal conductivity, the content should be 1.00% or less.
Ｍｎは、焼入性を向上させるが、多すぎるとＡ１変態点
を過度に低下させ、焼なまし硬さを過度に高くし、被切
削性を低下させるので１．００％以下とする。Mn improves hardenability, but if it is too large, it will excessively lower the A1 transformation point, excessively increase annealing hardness, and reduce machinability, so it should be kept at 1.00% or less.
Ｎ］はＣ、Ｃｒ、 Ｍｎ、 Ｍ０．Ｗなどとともに、本
発明鋼に優れた焼入性を付与し、緩やかな焼入冷却速度
の場合にも、マルテンサイト主体の組織を形成し、靭性
の低下を防ぐための重要な添加元素である。また基地の
本質的な靭性改善を与える。N] is C, Cr, Mn, M0. Together with W and the like, it is an important additive element that imparts excellent hardenability to the steel of the present invention, forms a martensite-based structure even at a slow quenching cooling rate, and prevents a decrease in toughness. . It also gives an essential toughness improvement to the base.
Ｎ１は」二記効果を得るために添加されるが、多ずぎる
とＡ１変態点を過度に高くして機械加工性を低下させる
ので、１．２０％以下とする。N1 is added in order to obtain the effect mentioned above, but if too much, the A1 transformation point becomes excessively high and the machinability is reduced, so it is limited to 1.20% or less.
Ｃｒは、適正な添加量の設定により焼もどし軟化抵抗、
および高温強度、Ｃと結合して炭化物を形成することに
よる耐摩耗性および焼入性をそれぞれ向」ユさせ、また
迅速窒化性を付与する効果を有するものである。Ｃｒは
低すぎると耐酸化性が不足し、使用時に肌あれを生じや
すく、上記の添加効果と共に本発明鋼の特徴である優れ
た靭性を得るために２．６０％以上添加する。高すぎる
と昇温時凝集しやすい炭化物を形成し、軟化抵抗、高温
強度を低下させるので４．００％以下とする。Cr improves tempering softening resistance by setting the appropriate amount of addition.
It has the effect of improving high-temperature strength, wear resistance and hardenability by combining with C to form carbides, and imparting rapid nitriding properties. If the content of Cr is too low, the oxidation resistance will be insufficient and roughness will easily occur during use.In addition to the above-mentioned effects of addition, 2.60% or more of Cr is added in order to obtain the excellent toughness that is a characteristic of the steel of the present invention. If the content is too high, carbides that tend to aggregate when the temperature rises are formed, reducing softening resistance and high-temperature strength, so the content should be 4.00% or less.
Ｗ、Ｍｏは、焼入加熱時、基地に固溶しにくい炭化物を
形成して耐摩耗性向上に効果をもたらすものであり、ま
た焼もどし時に微細な炭化物を析出して軟化抵抗、高温
強度を増加させる効果を有するものである。W and Mo form carbides that are difficult to dissolve in the matrix during quenching and heating, and are effective in improving wear resistance.They also precipitate fine carbides during tempering, increasing softening resistance and high-temperature strength. It has the effect of increasing
Ｗ、Ｍｏは上記の効果を得るために添加されるものであ
り、ＷとＭｏは１種または２種から選ばれて添加できる
。これは１／２ＷとＭｏの量がその添加効果において等
価であるからである。Ｗおよび／またはＭｏは多すぎる
と、Ｃ量の関係において、炭化物量が多くなりすぎて、
これが熱間加工方向に紐状に整列し、熱間加工方向への
クラックが伸展しやすくなり、また焼もどし時析出する
微細炭化物量が過度に増え靭性を低下させるため、］／
２Ｗ ＋Ｍｏで３．５０％以下とし、低すぎると上記添
加の効果が得ら九ないので２．６０％以上とする。W and Mo are added to obtain the above effects, and W and Mo can be added singly or in combination. This is because the amounts of 1/2W and Mo are equivalent in terms of their addition effects. If W and/or Mo are too large, the amount of carbides will become too large in relation to the amount of C,
These are arranged in a string shape in the hot working direction, making it easier for cracks to extend in the hot working direction, and the amount of fine carbides precipitated during tempering increases excessively, reducing toughness.]/
2W + Mo is set to 3.50% or less, and if it is too low, the effect of the above addition cannot be obtained, so it is set to 2.60% or more.
■は昇温時にも固溶しにくい炭化物を形成して耐摩耗性
および耐焼付性の向上に効果を有するものであり、焼入
加熱時に基地に固溶して焼もどし時に微細な凝集しにく
い炭化物を析出し、高い温度域における軟化抵抗を大と
し、大きな高温耐力を与えるための重要な元素である。■ is effective in improving wear resistance and seizure resistance by forming carbides that are difficult to dissolve in solid form even when the temperature is raised; they are dissolved in solid form in the matrix during quenching heating and are difficult to form fine agglomerations during tempering. It is an important element for precipitating carbides, increasing softening resistance in high temperature ranges, and providing large high-temperature yield strength.
また、■は結晶粒を微細化して靭性を向上させるととも
に、Ａ１変態点を上げるので、優れた高温耐力とあいま
って耐ヒートクラツク性を向−１−させる効果をもたら
すものである。In addition, (1) refines the crystal grains and improves toughness, and also raises the A1 transformation point, which together with excellent high-temperature yield strength, has the effect of improving heat crack resistance.
本発明鋼の特徴である優れた靭性と高温強度の兼備のた
めにＶ量の適量の設定は非常に重要である。■は多すぎ
ると巨大な炭化物を生成し、熱間方向に沿う紐状炭化物
の分布傾向を増大させ、熱間方向に沿うクラックの伸展
を助長するため、１．５０％以下とし、低すぎると型表
面部の早期軟化をまねくなど上記添加の効果が得られな
いので０．７１％以上とする。Setting an appropriate amount of V is very important in order to achieve both the excellent toughness and high-temperature strength that are the characteristics of the steel of the present invention. If it is too large, large carbides will be generated, increasing the distribution tendency of string-like carbides along the hot direction, and promoting the extension of cracks along the hot direction. Since the above-mentioned effects of addition cannot be obtained, such as causing early softening of the mold surface, the content should be 0.71% or more.
ＣＯは、使用中の昇温時、極めて緻密で密着性の良い保
護酸化皮膜を形成し、これにより金型表面と相手材との
間の金属接触がなくなり、金型表面の温度上昇を防ぐと
共に優れた耐摩耗性をもたらすものである。When the temperature rises during use, CO forms an extremely dense and highly adhesive protective oxide film, which eliminates metal contact between the mold surface and the other material, preventing the mold surface from rising in temperature. It provides excellent wear resistance.
また、この保護酸化皮膜形成により断熱効果が高まり、
面と相手材との間の金属接触がなくなり、金型表面を保
護することによる耐ヒートクラツク性の向上およびクラ
ック発生の起点の成形の抑制などの効果が得られるもの
である。In addition, the formation of this protective oxide film increases the insulation effect,
There is no metal contact between the surface and the mating material, and by protecting the mold surface, effects such as improved heat crack resistance and suppression of molding at the starting point of cracks can be obtained.
ＣＯは上記効果を付与するために添加するが、多すぎる
と靭性を低下させるので５．００％以下とし、低すぎる
と上記添加の効果が得られないので０．５０２以上とす
る。CO is added to provide the above effect, but if it is too large it will reduce the toughness, so it should be 5.00% or less, and if it is too low, the above effect of addition cannot be obtained, so it should be 0.502 or more.
Ｎは結晶粒の微細化効果をもたらし、本発明鋼の靭性向
上をもたらすもので、この目的のために添加を行なう。N has the effect of refining crystal grains and improves the toughness of the steel of the present invention, and is added for this purpose.
多量の添加は必要なく、溶製、造塊時の製造性を考慮し
て、０．１０％以下とする。It is not necessary to add a large amount, and the content should be 0.10% or less in consideration of productivity during melting and agglomeration.
ＳはＭｎと硫化物を形成し、熱間加工方向に伸びて分布
し、熱間加工方向の靭性を低下させるので少ない方がよ
い。これに及ぼすＳの影響は、０．００５％以下でその
効果が大きくなり、さらにＳ０．００３％以下でその効
果が際立って大きくなることを見出したものでＳの上限
を０．００５％とし、−層望ましい範囲を０．００３％
以下とする。S forms a sulfide with Mn, extends and distributes in the hot working direction, and reduces toughness in the hot working direction, so the smaller the amount, the better. It was found that the effect of S on this is large at 0.005% or less, and that the effect becomes significantly greater at 0.003% or less, so the upper limit of S is set at 0.005%. -layer desirable range 0.003%
The following shall apply.
以下、本発明を実施例に基づき詳細に説明する。 Hereinafter, the present invention will be explained in detail based on examples.
第１表に本発明鋼および従来鋼の化学組成を示す。Table 1 shows the chemical compositions of the steel of the present invention and the conventional steel.
第２表に本発明鋼および従来鋼の標準的な熱処理条件に
おける高温強度を示す。Table 2 shows the high temperature strength of the steel of the present invention and the conventional steel under standard heat treatment conditions.
高温強度は６５０℃、７００℃における引張強さで示す
。High temperature strength is indicated by tensile strength at 650°C and 700°C.
本発明鋼（Ａ−Ｆ）は従来鋼Ｇ（ＳＫＤ６１）に対し高
温強度が明らかに優れている。The steels of the present invention (A-F) are clearly superior in high temperature strength to the conventional steel G (SKD61).
また、本発明鋼を従来鋼Ｊ（特公昭５６−５４３７９号
に開示される鋼）、従来鋼Ｌ（特開昭６２−１４９８５
２号に開示される鋼）と比較すると６５０℃では強度の
差は比較的小さいが、７００℃で比較すると強度が明ら
かに優れている。これは本発明鋼の大きな特徴であり、
金型表面が６５０℃以上に昇温する用途の金型に本発明
鋼が使用されるとき、金型表面のヒートクラックや塑性
流動が起こりにくいことを示している。In addition, the steel of the present invention can be used as conventional steel J (steel disclosed in Japanese Patent Publication No. 56-54379), conventional steel L (steel disclosed in Japanese Patent Publication No. 62-14985).
The difference in strength is relatively small at 650°C compared to the steel disclosed in No. 2), but the strength is clearly superior when compared at 700°C. This is a major feature of the steel of the present invention,
This shows that when the steel of the present invention is used in a mold for which the temperature of the mold surface is raised to 650° C. or higher, heat cracks and plastic flow on the mold surface are less likely to occur.
第
表
第
表
次に、本発明鋼の高温強度と従来鋼Ｈ（ＳＫＤ７）、従
来鋼Ｉ（ＳＫＤ８）、従来鋼Ｋ（特開昭５４５０４２１
号）の高温強度とを比較すると同等ないしは従来鋼の方
が若干優れた値を示す。Table 1 Next, the high-temperature strength of the steel of the present invention, conventional steel H (SKD7), conventional steel I (SKD8), conventional steel K (Japanese Patent Application Laid-open No. 5450421
Comparing the high-temperature strength of No. 1), conventional steel shows equivalent or slightly superior values.
第３表は、第１表に示す本発明鋼および従来鋼試料を半
冷時間３０ｍ１ｎ （焼入温度と室温との中間温度まで
降温するまでの所要時間が３０ｍ１ｎとなるような冷却
速度）で焼入後、ＨＲＣ４５に焼もどした場合の破壊靭
性値（Ｋ ＩＣ）を示す。Table 3 shows the results of sintering the inventive steel and conventional steel samples shown in Table 1 with a half-cooling time of 30 m1n (cooling rate such that the time required to lower the temperature to an intermediate temperature between the quenching temperature and room temperature is 30 m1n). The fracture toughness value (K IC) is shown when the material is tempered to HRC45 after heating.
従来鋼Ｈ（ＳＫＤ７）、従来鋼Ｋ（特開昭５４５０４２
１号に開示される鋼）の場合は、半冷３０ｍｊｎの焼入
で上部ベイナイト主体の組織となるため、焼もどし後十
分な靭性が得られない。また従来鋼Ｉ（ＳＫＤ８）の場
合は、組織中に存在する炭化物が多すぎ靭性が低い。そ
のうえ、金型でテスト使用した結果では紐状に分布した
炭化物にそった大割れが早期に起こる頻度が多かった。Conventional Steel H (SKD7), Conventional Steel K (JP-A-545042
In the case of the steel disclosed in No. 1), it becomes a structure mainly composed of upper bainite by semi-cooling quenching for 30 mjn, and therefore sufficient toughness cannot be obtained after tempering. Furthermore, in the case of conventional steel I (SKD8), there are too many carbides present in the structure and the toughness is low. Furthermore, the results of test use in molds showed that large cracks along the string-like distribution of carbide often occurred early.
これに対し、本発明鋼は従来鋼Ｊに準する靭性値を備え
ている。In contrast, the steel of the present invention has a toughness value comparable to conventional steel J.
すなわち、従来鋼（Ｇ−Ｌ）は高温強度が優れる場合に
は、靭性が劣り（従来鋼Ｈ，Ｉ、Ｋ）、逆に靭性が優れ
る場合には、高温強度が劣る（従来鋼Ｇ。That is, when the conventional steel (GL) has excellent high-temperature strength, it has inferior toughness (conventional steels H, I, and K), and conversely, when it has excellent toughness, it has inferior high-temperature strength (conventional steel G).
Ｊ、Ｌ）のに対し、本発明鋼は高温強度、靭性の両者を
兼備していることがわかる。It can be seen that, in contrast to J and L), the steel of the present invention has both high temperature strength and toughness.
第４表に本発明鋼の耐ヒートクラツク性試験結果を示す
。この試験結果は、１５ｗｎφ×２５ｍの試験片の表面
を６８０℃に急熱し、水中で２０°Ｃに急冷する操作を
１５００回繰り返した結果である。Table 4 shows the heat crack resistance test results of the steel of the present invention. This test result is the result of repeating 1500 times the operation of rapidly heating the surface of a 15wnφ×25m test piece to 680°C and rapidly cooling it to 20°C in water.
本発明鋼は、従来鋼Ｇ、Ｊに比ベヒートクラック個数が
少ない。これは本発明鋼の大きな特色の一つであり、ヒ
ートクラックが発生しにくいことを示すものである。ヒ
ートクラックの深さは従来鋼と大差がない。The steel of the present invention has fewer beheat cracks than conventional steels G and J. This is one of the major features of the steel of the present invention, and shows that heat cracks are less likely to occur. The depth of heat cracks is not much different from conventional steel.
第５表は、本発明鋼の高温焼付試験における焼付臨界荷
重（比）を示す。試料は、円柱状試料で、熱処理、研磨
仕上後あらかじめ５５０°Ｃにおける空気酸化処理を行
なったのち、７００℃に加熱した鋼材（相手材）に高速
で回転しながら端面を押しつけた場合の焼付が起こらな
い最大荷重（臨界荷重）を求め、従来鋼Ｈ（ＳＫＤ７）
の焼付臨界荷重を１００として指数で示したものである
。Table 5 shows the baking critical load (ratio) in the high temperature baking test of the steel of the present invention. The sample was a cylindrical sample, and after heat treatment and polishing, it was previously subjected to air oxidation treatment at 550°C, and the end face was pressed against a steel material (component material) heated to 700°C while rotating at high speed. Determine the maximum load (critical load) that will not occur, and calculate the maximum load (critical load) that will not occur.
It is expressed as an index with the critical seizure load of 100.
本発明鋼は、従来鋼より明らかに焼付臨界荷重が高いこ
とがわかる。It can be seen that the steel of the present invention has a clearly higher seizure critical load than the conventional steel.
これは、本発明鋼は高温強度が高く、炭化物の適正な分
布などによる耐摩耗性付与効果に加えて、上記酸化処理
により本発明鋼の試料表面に形成された緻密で剥離しに
くい酸化皮膜による保護作用、ならびに潤滑作用による
ものであり、本発明鋼の大きな特色の一つである。This is because the steel of the present invention has high high-temperature strength, and in addition to the effect of imparting wear resistance due to proper distribution of carbides, this is due to the dense oxide film that is formed on the surface of the steel sample of the present invention by the above-mentioned oxidation treatment, which is difficult to peel off. This is due to the protective effect and lubricating effect, which is one of the major features of the steel of the present invention.
以上説明したように本願発明鋼は、ダイカスト型、熱間
鍛造型などの熱間加工用工具に使用されるのに十分な焼
入性を備えつつ、高温域の強度に優れた特性を有し、ま
た優れた酸化皮膜特性を備えている。そのため、工具の
へたり、ヒートクラック、大割れ、摩耗が生じにくく工
具寿命を延ばすことができるので、その効果は非常に大
きい。As explained above, the steel of the present invention has sufficient hardenability to be used in hot working tools such as die casting dies and hot forging dies, and has excellent strength in high temperature ranges. It also has excellent oxide film properties. Therefore, tool fatigue, heat cracks, large cracks, and wear are less likely to occur, and the tool life can be extended, which is extremely effective.
Claims (1)
下、Ｍｎ１．００％以下、Ｃｒ２．６０〜４．００％、
ＷとＭｏの１種または２種が１／２Ｗ＋Ｍｏで２．６０
〜３．５０％、Ｖ０．７１〜１．５％、Ｎｉ１．２０％
以下、Ｓ０．００５％以下、残部Ｆｅおよび不可避的不
純物からなることを特徴とする熱間加工用工具鋼。 ２ 重量％でＣ０．３６〜０．５％、Ｓｉ１．００％以
下、Ｍｎ１．００％以下、Ｃｒ２．６０〜４．００％、
ＷとＭｏの１種または２種が１／２Ｗ＋Ｍｏで２．６０
〜３．５０％、Ｖ０．７１〜１．５％、Ｎｉ１．２０％
以下、Ｃｏ０．５０〜５．００％、Ｓ０．００５％以下
、残部Ｆｅおよび不可避的不純物からなることを特徴と
する熱間加工用工具鋼。 ３ 重量％でＣ０．３６〜０．５％、Ｓｉ１．００％以
下、Ｍｎ１．００％以下、Ｃｒ２．６０〜４．００％、
ＷとＭｏの１種または２種が１／２Ｗ＋Ｍｏで２．６０
〜３．５０％、Ｖ０．７１〜１．５％、Ｎｉ１．２０％
以下、Ｓ０．００５％以下、Ｎ０．１０％以下、残部Ｆ
ｅおよび不可避的不純物からなることを特徴とする熱間
加工用工具鋼。 ４ 重量％でＣ０．３６〜０．５％、Ｓｉ１．００％以
下、Ｍｎ１．００％以下、Ｃｒ２．６０〜４．００％、
ＷとＭｏの１種または２種が１／２Ｗ＋Ｍｏで２．６０
〜３．５０％、Ｖ０．７１〜１．５％、Ｎｉ１．２０％
、以下、、Ｃｏ０．５０〜５．００％、Ｓ０．００５％
以下、Ｎ０．１０％以下、残部Ｆｅおよび不可避的不純
物からなることを特徴とする熱間加工用工具鋼。[Claims] 1% by weight: C 0.36-0.5%, Si 1.00% or less, Mn 1.00% or less, Cr 2.60-4.00%,
One or two types of W and Mo are 1/2W + Mo, 2.60
~3.50%, V0.71~1.5%, Ni1.20%
The following is a hot working tool steel characterized by comprising 0.005% or less of S, the balance being Fe and unavoidable impurities. 2% by weight: C 0.36-0.5%, Si 1.00% or less, Mn 1.00% or less, Cr 2.60-4.00%,
One or two types of W and Mo are 1/2W + Mo, 2.60
~3.50%, V0.71~1.5%, Ni1.20%
A tool steel for hot working characterized by comprising 0.50 to 5.00% Co, 0.005% or less S, and the balance Fe and unavoidable impurities. 3% by weight: C 0.36-0.5%, Si 1.00% or less, Mn 1.00% or less, Cr 2.60-4.00%,
One or two types of W and Mo are 1/2W + Mo, 2.60
~3.50%, V0.71~1.5%, Ni1.20%
Below, S 0.005% or less, N 0.10% or less, remainder F
A tool steel for hot working, characterized in that it consists of e and inevitable impurities. 4% by weight: C 0.36-0.5%, Si 1.00% or less, Mn 1.00% or less, Cr 2.60-4.00%,
One or two types of W and Mo are 1/2W + Mo, 2.60
~3.50%, V0.71~1.5%, Ni1.20%
, Hereinafter, Co0.50-5.00%, S0.005%
A tool steel for hot working characterized by comprising 0.10% or less of N, the remainder Fe and unavoidable impurities.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63194194A JP2953663B2 (en) | 1988-08-03 | 1988-08-03 | Tool steel for hot working |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63194194A JP2953663B2 (en) | 1988-08-03 | 1988-08-03 | Tool steel for hot working |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0243346A true JPH0243346A (en) | 1990-02-13 |
| JP2953663B2 JP2953663B2 (en) | 1999-09-27 |
Family
ID=16320515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63194194A Expired - Fee Related JP2953663B2 (en) | 1988-08-03 | 1988-08-03 | Tool steel for hot working |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2953663B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005264325A (en) * | 2004-02-18 | 2005-09-29 | Sumitomo Denko Shoketsu Gokin Kk | Sintered high speed steel and method for manufacturing the same, and sliding components made of the sintered high speed steel |
| US7494618B2 (en) * | 2004-01-26 | 2009-02-24 | Daido Tokushuko Kabushiki Kaisha | Alloy tool steel |
| JP2018109235A (en) * | 2012-05-07 | 2018-07-12 | ヴァルス ベジッツ ゲーエムベーハー | Low temperature hard steel with excellent machinability |
| JP2021505772A (en) * | 2017-12-12 | 2021-02-18 | ポスコＰｏｓｃｏ | Heat treatment curable high carbon steel sheet and its manufacturing method |
| EP4219783A1 (en) * | 2014-03-18 | 2023-08-02 | Innomaq 21, Sociedad Limitada | Extremely high conductivity low cost steel |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5450421A (en) * | 1977-09-30 | 1979-04-20 | Daido Steel Co Ltd | Hot tool steel |
| JPS62112761A (en) * | 1985-11-12 | 1987-05-23 | Hitachi Metals Ltd | Tool steel for warm and hot working |
| JPS62149852A (en) * | 1985-12-23 | 1987-07-03 | Hitachi Metals Ltd | Tool steel for hot working |
-
1988
- 1988-08-03 JP JP63194194A patent/JP2953663B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5450421A (en) * | 1977-09-30 | 1979-04-20 | Daido Steel Co Ltd | Hot tool steel |
| JPS62112761A (en) * | 1985-11-12 | 1987-05-23 | Hitachi Metals Ltd | Tool steel for warm and hot working |
| JPS62149852A (en) * | 1985-12-23 | 1987-07-03 | Hitachi Metals Ltd | Tool steel for hot working |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7494618B2 (en) * | 2004-01-26 | 2009-02-24 | Daido Tokushuko Kabushiki Kaisha | Alloy tool steel |
| JP2005264325A (en) * | 2004-02-18 | 2005-09-29 | Sumitomo Denko Shoketsu Gokin Kk | Sintered high speed steel and method for manufacturing the same, and sliding components made of the sintered high speed steel |
| JP2018109235A (en) * | 2012-05-07 | 2018-07-12 | ヴァルス ベジッツ ゲーエムベーハー | Low temperature hard steel with excellent machinability |
| EP4219783A1 (en) * | 2014-03-18 | 2023-08-02 | Innomaq 21, Sociedad Limitada | Extremely high conductivity low cost steel |
| JP2021505772A (en) * | 2017-12-12 | 2021-02-18 | ポスコＰｏｓｃｏ | Heat treatment curable high carbon steel sheet and its manufacturing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2953663B2 (en) | 1999-09-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TW200305655A (en) | Steel block for the manufacture of moulds for the injection moulding of plastics material or for the manufacture of metal-working parts | |
| CN103282530B (en) | Die steel excellent in rust resistance and thermal conductivity, and manufacturing method thereof | |
| CN102912241B (en) | A kind of moulding stock of heat-resistant antifriction | |
| KR100368540B1 (en) | A low alloyed high speed tool steel for hot and warm working having good toughness and high strength and manufacture method thereof | |
| CN101743335A (en) | Steel for cold working dies and dies for cold stamping | |
| CN113621876A (en) | Manufacturing method of high-performance hot-work die steel | |
| CN115679194B (en) | Plastic mold steel plate and manufacturing method thereof | |
| JP2953663B2 (en) | Tool steel for hot working | |
| JP2005336553A (en) | Hot work tool steel | |
| JPS6154864B2 (en) | ||
| JPH0688166A (en) | Mold for hot working with excellent heat crack resistance | |
| JPH11106868A (en) | Tool steel for hot working | |
| JP2001214238A (en) | Powder hot tool steel excellent in heat crack resistance and wear resistance and hot die | |
| JPH03134135A (en) | Tool steel for hot working | |
| CN103233170A (en) | Steel for hot working mold and production method thereof | |
| JP2755301B2 (en) | Tool steel for hot working | |
| JPS62112761A (en) | Tool steel for warm and hot working | |
| JPH04318148A (en) | Tool steel for hot working | |
| JP2746919B2 (en) | Tool steel for warm and hot working | |
| JPH02125840A (en) | Tool steel for hot working | |
| JP3191008B2 (en) | Hot tool steel | |
| JPH06145884A (en) | Die for hot working excellent in plastic flow resistance | |
| JPH028347A (en) | Tool steel for warm and hot working | |
| JP3196901B2 (en) | Steel for aluminum extrusion dies | |
| JPH07278737A (en) | Pre-hardened steel for plastic molding and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |