JP6345945B2 - Powdered high-speed tool steel with excellent wear resistance and method for producing the same - Google Patents
Powdered high-speed tool steel with excellent wear resistance and method for producing the same Download PDFInfo
- Publication number
- JP6345945B2 JP6345945B2 JP2014034797A JP2014034797A JP6345945B2 JP 6345945 B2 JP6345945 B2 JP 6345945B2 JP 2014034797 A JP2014034797 A JP 2014034797A JP 2014034797 A JP2014034797 A JP 2014034797A JP 6345945 B2 JP6345945 B2 JP 6345945B2
- Authority
- JP
- Japan
- Prior art keywords
- carbide
- diameter
- area ratio
- wear resistance
- less
- 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.)
- Active
Links
- 229910001315 Tool steel Inorganic materials 0.000 title claims description 28
- 238000004519 manufacturing process Methods 0.000 title claims description 6
- 239000000843 powder Substances 0.000 claims description 34
- 150000001247 metal acetylides Chemical class 0.000 claims description 32
- 229910000831 Steel Inorganic materials 0.000 claims description 20
- 239000010959 steel Substances 0.000 claims description 19
- 238000000465 moulding Methods 0.000 claims description 9
- 238000007711 solidification Methods 0.000 claims description 9
- 230000008023 solidification Effects 0.000 claims description 9
- 238000005242 forging Methods 0.000 claims description 8
- 238000005096 rolling process Methods 0.000 claims description 8
- 238000010791 quenching Methods 0.000 claims description 7
- 230000000171 quenching effect Effects 0.000 claims description 7
- 239000012535 impurity Substances 0.000 claims description 4
- 238000005520 cutting process Methods 0.000 description 14
- 230000000694 effects Effects 0.000 description 13
- 238000001513 hot isostatic pressing Methods 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 10
- 239000000203 mixture Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 8
- 229910052721 tungsten Inorganic materials 0.000 description 8
- 229910052720 vanadium Inorganic materials 0.000 description 8
- 229910052799 carbon Inorganic materials 0.000 description 7
- 229910052804 chromium Inorganic materials 0.000 description 7
- 229910052748 manganese Inorganic materials 0.000 description 7
- 238000005496 tempering Methods 0.000 description 7
- 229910052750 molybdenum Inorganic materials 0.000 description 6
- 229910052710 silicon Inorganic materials 0.000 description 6
- 229910000997 High-speed steel Inorganic materials 0.000 description 4
- 239000005539 carbonized material Substances 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 238000004663 powder metallurgy Methods 0.000 description 2
- 238000005204 segregation Methods 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000009689 gas atomisation Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- OXNIZHLAWKMVMX-UHFFFAOYSA-N picric acid Chemical compound OC1=C([N+]([O-])=O)C=C([N+]([O-])=O)C=C1[N+]([O-])=O OXNIZHLAWKMVMX-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
- Heat Treatment Of Articles (AREA)
Description
本発明は、切削工具や金型等に使用される粉末高速度工具鋼およびその製造方法に関する。 The present invention relates to powder high-speed tool steel used for cutting tools, dies, and the like, and a method for producing the same.
従来、高速度工具鋼はＣ，Ｃｒ，Ｗ，Ｍｏ，Ｖ，Ｃｏ等の合金元素を多量に加えて高温で硬さや耐摩耗性を一層高めた工具鋼であり、エンドミルやドリルのように比較的靱性が要求される切削工具の素材として汎用されている。ところで、このような高速度工具鋼は、従来では溶製法によって製造されていたのであるが、この溶製法によって得られた高速度工具鋼では、粗大炭化物の存在や偏析という問題があったことから、近年では、従来の溶製法に代わって、粉末冶金法を用いた粉末高速度工具鋼が広く使用されるようになっている。この粉末高速度工具鋼は、高速度工具鋼の溶湯をアトマイズ法によって急冷凝固粉末とし、この粉末を熱間静水圧加圧（ＨＩＰ）等の粉末冶金法によって製造される。 Conventionally, high-speed tool steel is a tool steel that has been further increased in hardness and wear resistance at high temperatures by adding a large amount of alloying elements such as C, Cr, W, Mo, V, Co, etc. Compared to end mills and drills It is widely used as a material for cutting tools that require high toughness. By the way, such a high-speed tool steel has been conventionally produced by a melting method, but the high-speed tool steel obtained by this melting method has problems such as the presence of coarse carbides and segregation. In recent years, powder high-speed tool steel using a powder metallurgy method has been widely used in place of the conventional melting method. This powder high-speed tool steel is produced by a powder metallurgy method such as hot isostatic pressing (HIP) using a molten metal of the high-speed tool steel as a rapidly solidified powder by an atomizing method.
一方、上記のような粉末高速度工具鋼を切削工具の素材として実際使用した場合には、耐摩耗性および靱性が不十分なことから、工具の切削性能の向上という要求に十分対応できないことから、耐摩耗性および靱性をより高めて工具の切削性能をより向上させると言う観点で、これまでにも様々な粉末高速度工具鋼について提案されている。
例えば、特開２００１−２９４９８６号公報（特許文献１）に開示されているように、Ｃ：１．２〜３％、Ｓｉ：≦３．０％、Ｍｎ：≦３．０％、Ｃｒ：３〜６％、Ｗ：１０〜１５％、Ｍｏ：≦１．０％、Ｖ：３〜５％、Ｃｏ：≦１０％を含有する高速度工具鋼用粉末が提案されている。
On the other hand, when powder high-speed tool steel as described above is actually used as a raw material for cutting tools, the wear resistance and toughness are insufficient, and the demand for improved tool cutting performance cannot be fully met. Various powder high-speed tool steels have been proposed so far in view of further improving wear resistance and toughness to further improve the cutting performance of the tool.
For example, as disclosed in Japanese Patent Application Laid-Open No. 2001-294986 (Patent Document 1), C: 1.2 to 3%, Si: ≦ 3.0%, Mn: ≦ 3.0%, Cr: 3 High-speed tool steel powders containing -6%, W: 10-15%, Mo: ≤ 1.0%, V: 3-5%, Co: ≤ 10% have been proposed.
また、特開平９−５９７４８号公報（特許文献２）に開示されているように、ＮｉおよびＣｏを含むＭｏ系高速度工具鋼であって、Ｎｂを０．５〜２．０％含有すると共に、炭化物の平均粒径が０．４０〜０．８０μｍであり、且つ最大粒径が５μｍ以下である耐摩耗性及び耐チッピング性に優れた粉末高速度工具鋼が提案されている。 Further, as disclosed in JP-A-9-59748 (Patent Document 2), it is a Mo-based high-speed tool steel containing Ni and Co, and contains 0.5 to 2.0% of Nb. A powder high-speed tool steel excellent in wear resistance and chipping resistance having an average particle size of carbide of 0.40 to 0.80 μm and a maximum particle size of 5 μm or less has been proposed.
さらに、特開平４−３５８０４６号公報（特許文献３）は、Ｃ：１．７〜３．５％、Ｓｉ：≦０．４％、Ｍｎ：≦０．４％、Ｃｒ：３〜２０％、Ｖ，Ｔｉ，Ｎｂのいずれか１種ないし２種以上の元素：≦１２％、Ｗ：５〜１４％、Ｍｏ：３〜９％、Ｃｏ：７〜１４％、残部実質的にＦｅからなり、基地中に、粒径１０〜５０μｍの炭化物粒が均一に分散し、その面積率は１０〜５０％である耐摩耗性・靱性等にすぐれた高速度鋼系焼結合金が提案されている。 Furthermore, JP-A-4-358046 (Patent Document 3) describes C: 1.7 to 3.5%, Si: ≦ 0.4%, Mn: ≦ 0.4%, Cr: 3 to 20%, One or more elements of V, Ti, Nb: ≦ 12%, W: 5-14%, Mo: 3-9%, Co: 7-14%, the balance substantially consisting of Fe, A high-speed steel-based sintered alloy having excellent wear resistance, toughness, etc., in which carbide grains having a particle size of 10 to 50 μm are uniformly dispersed in the base and the area ratio is 10 to 50% has been proposed.
上述した、特許文献１は成分制御により耐摩耗性、靱性改善を狙っているが、しかし、炭化物サイズが２．０μｍと微細で、耐摩耗性に懸念があり十分ではない。また、特許文献２はＮｂを０．５〜２．０％添加し、かつＮｉ，Ｃｏを含む粉末高速度鋼と耐摩耗性、靱性を高めているが、しかしながら、Ｎｂを含む必要があり、そのため成分系に制約があり、コストアップに繋がる問題がある。さらに、特許文献３は１０〜５０μｍの炭化物を１０〜５０％含む粉末高速度鋼で、破壊靱性改善を狙っているが、本発明の観点から見ると微細な炭化物が殆ど存在しないことに起因して、耐チッピング性に問題がある。 The above-mentioned Patent Document 1 aims to improve wear resistance and toughness by controlling the components. However, the carbide size is as small as 2.0 μm, and there is concern about wear resistance, which is not sufficient. In addition, Patent Document 2 adds 0.5 to 2.0% of Nb and improves the high-speed powder steel and wear resistance and toughness including Ni and Co. However, it is necessary to include Nb. Therefore, there is a problem in the component system, leading to cost increase. Furthermore, Patent Document 3 is a powder high-speed steel containing 10 to 50% carbide of 10 to 50 μm, and aims to improve fracture toughness. However, from the viewpoint of the present invention, there is almost no fine carbide. There is a problem with chipping resistance.
一般に、粉末高速度工具鋼は、微細な炭化物が析出するため靱性に優れる特徴を持ち、上記特許文献１〜３のような粉末高速度工具鋼が提案されているが、近年の切削工具に要求されるより高度な特性（例えば高速で切削を行う場合の特性）が求められた場合には、耐摩耗性や靱性が依然として不十分であり、さらなる改善が求められているのが現状である。 In general, powder high-speed tool steel has characteristics of excellent toughness because fine carbides precipitate, and powder high-speed tool steels such as those in Patent Documents 1 to 3 have been proposed. However, when more advanced characteristics (for example, characteristics when cutting at high speed) are required, the wear resistance and toughness are still insufficient, and further improvements are required.
例えば、粉末高速度工具鋼の耐摩耗性を改善する方法として、非特許文献１（電気製鋼、第５８巻 第４号 ２５１〜２５９頁 常陸美朝、松田幸紀著）にて、組織中の炭化物を多量に析出させたり、大きくすることが有効であるが、過度に行うと靱性が低下する場合があることが報告されている。しかし、この報告では高速切削用途の工具に実際に使用した時の耐摩耗性については記載されておらず、高速切削用途の工具に適した成分、炭化物の大きさ、量、すなわち、耐摩耗性と靱性のバランスの最適値、そして、その場合の工具寿命については述べられていない。そこで、実際に高速切削用途の粉末高速度鋼の成分と組織中の炭化物を適切に制御することにより、耐摩耗性と靱性に優れた粉末高速度工具鋼を得ることを目的としたものである。 For example, as a method for improving the wear resistance of powder high-speed tool steel, Non-Patent Document 1 (Electric Steel, Vol. 58, No. 4, pp. 251-259, written by Mika Hitachi and Yuki Matsuda) It is effective to precipitate a large amount or increase the amount, but it has been reported that if it is excessively performed, the toughness may be lowered. However, this report does not describe the wear resistance when actually used for tools for high speed cutting applications, and the components, carbide size and quantity suitable for tools for high speed cutting applications, that is, wear resistance. The optimum balance between toughness and toughness and the tool life in that case are not mentioned. Therefore, it is intended to obtain powder high-speed tool steel with excellent wear resistance and toughness by appropriately controlling the composition of powder high-speed steel for high-speed cutting applications and carbides in the structure. .
その発明の要旨とするところは、
（１）質量％で、Ｃ：１．０〜１．８％、Ｓｉ：０．１〜１．０％、Ｍｎ：０．１〜１．０％、Ｃｒ：２．０〜７．０％、Ｍｏ：２．０〜７．０％、Ｗ：３．０〜１５．０％、Ｖ：２．０〜５．０％を含有し、残部Ｆｅおよび不可避的不純物よりなる鋼粉末を固化成形後、鍛造または圧延により熱間加工後、焼入、焼戻したミクロ組織において１００μｍ2中の炭化物径（円相当径）の最大値が２〜１０μｍの範囲にあり、さらに、炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％、２μｍ未満の微細炭化物の面積率が３〜１０％であることを特徴とする耐摩耗性に優れた粉末高速度工具鋼。
The gist of the invention is that
(1) By mass%, C: 1.0 to 1.8%, Si: 0.1 to 1.0%, Mn: 0.1 to 1.0%, Cr: 2.0 to 7.0% , Mo: 2.0 to 7.0%, W: 3.0 to 15.0%, V: 2.0 to 5.0%, solidified and formed into a steel powder comprising the remainder Fe and inevitable impurities Then, after hot working by forging or rolling, the maximum value of the carbide diameter (equivalent circle diameter) in 100 μm 2 in the quenched and tempered microstructure is in the range of 2 to 10 μm, and the carbide diameter is 2 to 10 μm. A powder high-speed tool steel excellent in wear resistance, characterized in that the area ratio of coarse carbides is 2 to 10%, and the area ratio of fine carbides less than 2 μm is 3 to 10%.
（２）質量％で、Ｃ：１．０〜１．８％、Ｓｉ：０．１〜１．０％、Ｍｎ：０．１〜１．０％、Ｃｒ：２．０〜７．０％、Ｍｏ：２．０〜７．０％、Ｗ：３．０〜１５．０％、Ｖ：２．０〜５．０％、Ｃｏ：１０．０％以下を含有し、残部Ｆｅおよび不可避的不純物よりなる鋼粉末を固化成形後、鍛造または圧延により熱間加工後、焼入、焼戻したミクロ組織において１００μｍ2中の炭化物径（円相当径）の最大値が２〜１０μｍの範囲にあり、さらに、炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％、２μｍ未満の微細炭化物の面積率が３〜１０％であることを特徴とする耐摩耗性に優れた粉末高速度工具鋼。 (2) By mass%, C: 1.0 to 1.8%, Si: 0.1 to 1.0%, Mn: 0.1 to 1.0%, Cr: 2.0 to 7.0% , Mo: 2.0 to 7.0%, W: 3.0 to 15.0%, V: 2.0 to 5.0%, Co: 10.0% or less, balance Fe and inevitable after solidifying and molding a steel powder of impurity, after hot working by forging or rolling, quenching, in the range the maximum value is 2~10μm carbide diameter of 100μm 2 in tempered microstructure (equivalent circle diameter), Furthermore, the powder high speed tool excellent in wear resistance, characterized in that the area ratio of coarse carbide having a carbide diameter of 2 to 10 μm is 2 to 10%, and the area ratio of fine carbide having a diameter of less than 2 μm is 3 to 10%. steel.
（３）前記（１）または（２）に記載の鋼粉末を、１２００〜１２４０℃の温度域でＨＩＰ固化成形を行う後、鍛造または圧延により熱間加工後、焼入、焼戻したミクロ組織において１００μｍ2 中の炭化物径（円相当径）の最大値が２〜１０μｍの範囲にあり、さらに、炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％、２μｍ未満の微細炭化物の面積率が３〜１０％としたことを特徴とする耐摩耗性に優れた粉末高速度工具鋼の製造方法。 (3) In the microstructure in which the steel powder described in the above (1) or (2) is subjected to HIP solidification in a temperature range of 1200 to 1240 ° C., then hot worked by forging or rolling, and then quenched and tempered. The maximum value of the carbide diameter (equivalent circle diameter) in 100 μm 2 is in the range of 2 to 10 μm, and the area ratio of coarse carbide having a carbide diameter of 2 to 10 μm is 2 to 10%, and the area of fine carbide less than 2 μm. A method for producing powder high-speed tool steel having excellent wear resistance, characterized in that the rate is 3 to 10%.
（４）前記（１）または（２）に記載の鋼粉末を、１１００〜１２００℃未満の温度域でＨＩＰ固化成形を行い、１２００〜１２４０℃の温度域で２時間以上保持する熱処理後、鍛造または圧延による熱間加工後、焼入、焼戻したミクロ組織において１００μｍ2 中の炭化物径（円相当径）の最大値が２〜１０μｍの範囲にあり、さらに、炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％、２μｍ未満の微細炭化物の面積率が３〜１０％としたことを特徴とする耐摩耗性に優れた粉末高速度工具鋼の製造方法にある。 (4) The steel powder described in the above (1) or (2) is subjected to HIP solidification molding in a temperature range of 1100 to less than 1200 ° C., and after heat treatment for 2 hours or more in a temperature range of 1200 to 1240 ° C., forging Alternatively, after the hot working by rolling, in the quenched and tempered microstructure, the maximum carbide diameter (equivalent circle diameter) in 100 μm 2 is in the range of 2 to 10 μm, and the coarse carbide has a carbide diameter of 2 to 10 μm. The area ratio of fine carbides having a surface area of 2 to 10% and a fine carbide of less than 2 μm is 3 to 10%.
以上述べたように、本発明により耐摩耗性および靱性をより優れるものとすることによって、切削工具のより長寿命化を達成することができるような粉末高速度工具鋼、およびこうした高速度工具鋼の製造方法を提供することが出来る。 As described above, the powder high-speed tool steel capable of achieving a longer tool life by making the present invention more excellent in wear resistance and toughness, and such a high-speed tool steel. The manufacturing method can be provided.
以下、本発明に係る限定理由について説明する。
Ｃ：１．０〜１．８％
Ｃは、硬さ、焼入性に必要な元素である。しかし、１．０％未満ではその効果が十分でない。また、１．８％を超えると、靱性、加工性を悪化させることから、その範囲を１．０〜１．８％とした。
Hereinafter, the reason for limitation according to the present invention will be described.
C: 1.0 to 1.8%
C is an element necessary for hardness and hardenability. However, the effect is not sufficient if it is less than 1.0%. Further, if it exceeds 1.8%, the toughness and workability deteriorate, so the range was made 1.0 to 1.8%.
Ｓｉ：０．１〜１．０％
Ｓｉは、脱酸剤であり、基地の硬さを得るために必要な元素である。しかし、０．１％未満では、その効果が十分に得られず、１．０％を超えると靱性と加工性が悪化することから、その範囲を０．１〜１．０％とした。
Si: 0.1 to 1.0%
Si is a deoxidizer and is an element necessary for obtaining the hardness of the matrix. However, if it is less than 0.1%, the effect is not sufficiently obtained, and if it exceeds 1.0%, toughness and workability deteriorate, so the range was made 0.1 to 1.0%.
Ｍｎ：０．１〜１．０％
Ｍｎは、脱酸剤であり、焼入性を得るために必要な元素である。しかし、０．１％未満では、その効果が十分に得られず、１．０％を超えるとマトリックスを脆化させ靱性、熱間加工性が悪化することから、その範囲を０．１〜１．０％とした。
Mn: 0.1 to 1.0%
Mn is a deoxidizer and is an element necessary for obtaining hardenability. However, if the content is less than 0.1%, the effect cannot be obtained sufficiently. If the content exceeds 1.0%, the matrix becomes brittle and the toughness and hot workability deteriorate. 0.0%.
Ｃｒ：３．０〜７．０％
Ｃｒは、焼入性を得るために必要な元素である。しかし、３．０％未満ではその効果が十分でない。また、７．０％を超えると靱性、熱間加工性が悪化することから、その範囲を３．０〜７．０％とした。
Cr: 3.0-7.0%
Cr is an element necessary for obtaining hardenability. However, if it is less than 3.0%, the effect is not sufficient. Further, if it exceeds 7.0%, the toughness and hot workability deteriorate, so the range was made 3.0 to 7.0%.
Ｍｏ：２．０〜７．０％
Ｍｏは、炭化物を形成し、焼入性、硬さおよび耐摩耗性を与え、かつ焼戻し軟化抵抗性を得るために必要な元素である。しかし、２．０％未満ではその効果が十分でない。また、７．０％を超えると靱性、熱間加工性が悪化することから、その範囲を２．０〜７．０％とした。好ましくは３．０〜７．０％とする。
Mo: 2.0-7.0%
Mo is an element necessary for forming carbide, giving hardenability, hardness and wear resistance, and obtaining temper softening resistance. However, if it is less than 2.0%, the effect is not sufficient. Moreover, since toughness and hot workability will deteriorate when it exceeds 7.0%, the range was made into 2.0 to 7.0%. Preferably it is 3.0 to 7.0%.
Ｗ：３．０〜１５．０％
Ｗは、Ｍｏと同様に、炭化物を形成し、焼入性、硬さおよび耐摩耗性を与え、かつ焼戻し軟化抵抗性を得るために必要な元素である。しかし、３．０％未満ではその効果が十分でない。また、１５．０％を超えると靱性、熱間加工性が悪化することから、その範囲を３．０〜１５．０％とした。好ましくは４．０〜１３．０％とする。
W: 3.0-15.0%
W, like Mo, is an element necessary for forming carbide, imparting hardenability, hardness and wear resistance, and obtaining temper softening resistance. However, if it is less than 3.0%, the effect is not sufficient. Moreover, since toughness and hot workability will deteriorate when it exceeds 15.0%, the range was made into 3.0 to 15.0%. Preferably it is 4.0 to 13.0%.
Ｖ：２．０〜５．０％
Ｖは、微細な炭化物を形成し２次硬化に寄与し、耐軟化抵抗性を改善し、結粒微細化および耐摩耗性を得るために必要な元素である。しかし、２．０％未満ではその効果が十分でない。また、５．０％を超えると靱性、被削性が悪化することから、その範囲を２．０〜５．０％とした。好ましくは３．０〜４．０％とする。
V: 2.0-5.0%
V is an element necessary for forming fine carbides and contributing to secondary curing, improving resistance to softening, and obtaining finer grains and wear resistance. However, if it is less than 2.0%, the effect is not sufficient. Further, if it exceeds 5.0%, the toughness and machinability deteriorate, so the range was made 2.0 to 5.0%. Preferably it is 3.0 to 4.0%.
Ｃｏ：１０．０％以下
Ｃｏは、耐熱性、耐摩耗性、耐焼戻し軟化抵抗性を得るために必要な元素である。本元素を含まなくても本発明の効果は得られるが、高速切削用途の工具鋼では、使用時の温度上昇から耐熱性、耐焼戻し軟化抵抗性が特に重要となるため、含有することが好ましい。しかし、１０．０％を超える添加は炭化物の偏析や脱炭を促進することから、その範囲を１０．０％以下とした。
Co: 10.0% or less Co is an element necessary for obtaining heat resistance, wear resistance, and tempering softening resistance. The effect of the present invention can be obtained even if this element is not included, but in tool steel for high-speed cutting applications, heat resistance and resistance to tempering softening are particularly important due to temperature rise during use, so it is preferable to contain it. . However, addition over 10.0% promotes segregation and decarburization of carbides, so the range was made 10.0% or less.
１００μｍ2 中の炭化物径（円相当径）の最大値が２〜１０μｍ
上記炭化物径の範囲を設定するに当たって、耐摩耗性を改善するには、炭化物を大きくすることが有効であるが、過度に炭化物を大きくすると靱性が低下することが、電気製鋼、第５８巻 第４号 ２５１〜２５９頁 常陸 美朝、松田 幸紀著（非特許文献１）に報告されている。そのため、微細な炭化物と粗大な炭化物を混在させることにより、靱性を保ちつつ耐摩耗性を改善することができると考え、１００μｍ2 中の炭化物径（円相当径）の最大値が２μｍとした場合に耐摩耗性が向上することを見出した。しかし、炭化物径が１０μｍを超えると靱性を著しく阻害し、チッピングを誘発するため、炭化物円相当径の最大値を２〜１０μｍとした。
The maximum value of carbide diameter (equivalent circle diameter) in 100 μm 2 is 2 to 10 μm
In setting the range of the carbide diameter, it is effective to increase the carbide in order to improve the wear resistance. However, if the carbide is excessively increased, the toughness is lowered. No. 4, pp. 251 to 259 This is reported in Hitachi Minako and Matsuda Yuki (non-patent document 1). Therefore, it is considered that wear resistance can be improved while maintaining toughness by mixing fine carbide and coarse carbide, and the maximum value of the carbide diameter (equivalent circle diameter) in 100 μm 2 is 2 μm. It was found that the wear resistance was improved. However, when the carbide diameter exceeds 10 μm, the toughness is remarkably inhibited and chipping is induced. Therefore, the maximum value of the carbide equivalent diameter is set to 2 to 10 μm.
炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％
耐摩耗性を向上させるためには、炭化物径の最大値と共に、２〜１０μｍである粗大炭化物の面積率が重要であることを見出した。２〜１０μｍの粗大炭化物の面積率が２％以上ないと耐摩耗性向上の効果が十分に得られない。また、１０％を超えると靱性が低下するために、炭化物径が２〜１０μｍの粗大炭化物の面積率を２〜１０％とする。
The area ratio of coarse carbide having a carbide diameter of 2 to 10 μm is 2 to 10%.
In order to improve the wear resistance, it has been found that the area ratio of coarse carbides of 2 to 10 μm is important together with the maximum value of the carbide diameter. If the area ratio of coarse carbides of 2 to 10 μm is 2% or more, the effect of improving wear resistance cannot be obtained sufficiently. Moreover, since toughness will fall when it exceeds 10%, the area ratio of the coarse carbide | carbonized_material of 2-10 micrometers of carbide diameters shall be 2-10%.
２μｍ未満の微細炭化物の面積率が３〜１０％
靱性を確保してチッピングを防止するために、２μｍ未満の微細炭化物が存在しなくてはならない。微細炭化物が存在しないと、組織中の結晶粒成長をピン止め効果が得られず、結晶粒粗大化が起きやすくなり母相の靱性が低下し、チッピングが起こりやすくなる。チッピングを防止する効果は、２μｍ未満の微細炭化物の面積率が３％以上でなければ十分に得られない。また、微細炭化物の面積率が１０％を超えると粗大炭化物が形成されにくく耐摩耗性の向上効果が得られないことから、その微細炭化物の面積率を３〜１０％とした。
The area ratio of fine carbides less than 2 μm is 3 to 10%
In order to ensure toughness and prevent chipping, there must be fine carbides less than 2 μm. Without the presence of fine carbides, the effect of pinning the crystal grain growth in the structure cannot be obtained, the crystal grain coarsening tends to occur, the toughness of the parent phase decreases, and chipping tends to occur. The effect of preventing chipping cannot be sufficiently obtained unless the area ratio of fine carbides less than 2 μm is 3% or more. Further, if the area ratio of fine carbides exceeds 10%, coarse carbides are hardly formed and the effect of improving wear resistance cannot be obtained. Therefore, the area ratio of the fine carbides was set to 3 to 10%.
図１は、本発明鋼（表Ｎｏ．１）の焼入れ焼戻し後の炭化物状況を示す図である。この図に示すように、本発明に示す成分組成、ＨＩＰ条件で作製し、炭化物最大径、面積率を制御して粗大炭化物と微細炭化物が混在する組織に制御しているため耐摩耗性が向上し、耐チッピング性にも優れている。また図２は、比較例鋼（表Ｎｏ．１１）の焼入れ焼戻し後の炭化物状況を示す図である。この図に示すように、本発明に示す成分組成と同じであるが、本発明の条件で作製せず、炭化物が微細で本発明範囲外のため耐摩耗性に劣る。 FIG. 1 is a view showing a carbide state after quenching and tempering of the steel of the present invention (Table No. 1). As shown in this figure, the wear resistance is improved because it is manufactured under the component composition and HIP conditions shown in the present invention, and controlled to a structure in which coarse carbide and fine carbide are mixed by controlling the maximum carbide diameter and area ratio. And excellent chipping resistance. FIG. 2 is a view showing a carbide state after quenching and tempering of the comparative example steel (Table No. 11). As shown in this figure, it is the same as the component composition shown in the present invention, but it is not produced under the conditions of the present invention, and the carbide is fine and out of the scope of the present invention, resulting in poor wear resistance.
高速度工具鋼の成分に調整した金属粉末に対して、１２００〜１２４０℃の温度域でＨＩＰ固化成形を行う。もしくは、１１００〜１２００℃未満でＨＩＰ固化成形を行い１００％密度としたビレットに対して、１２００〜１２４０℃の温度範囲で２時間以上保持する熱処理を行う。上記の処理を行う理由としては、ＨＩＰ固化成形中、もしくはその後の工程において、１２００℃で２時間以上で保持を行うことで、炭化物の成長を促し炭化物の大きさを制御するためである。ただし、１２４０℃より高い温度で保持を行うと、炭化物の成長が顕著になり過ぎ、微細な炭化物が消失、それに伴い結晶粒の粗大化が起こり靱性が著しく低下するため１２４０℃を上限とした。例えば、１２５０℃でＨＩＰ固化成形を行った比較鋼（表Ｎｏ．１３）の組織を図３に示す。この図３は、本発明範囲外の成分組成であり、かつ１２５０℃でＨＩＰ固化成形を行っているため、炭化物が顕著に粗大化し、微細炭化物が殆んど存在しないことから、結晶粒が粗大化している。そのため耐チッピング性が悪い。 HIP solidification molding is performed in a temperature range of 1200 to 1240 ° C. with respect to the metal powder adjusted to the component of the high-speed tool steel. Alternatively, heat treatment is performed on the billet that is HIP solidified at 1100 to less than 1200 ° C. and made 100% density, and is held in a temperature range of 1200 to 1240 ° C. for 2 hours or more. The reason for performing the above treatment is to promote the growth of carbides and control the size of the carbides by holding at 1200 ° C. for 2 hours or more during the HIP solidification molding or in the subsequent steps. However, when holding at a temperature higher than 1240 ° C., carbide growth becomes excessive, fine carbide disappears, crystal grains become coarser, and the toughness is remarkably lowered. For example, the structure of the comparative steel (Table No. 13) subjected to HIP solidification at 1250 ° C. is shown in FIG. This FIG. 3 is a component composition outside the scope of the present invention, and since HIP solidification molding is performed at 1250 ° C., the carbides are significantly coarsened and there are almost no fine carbides, so the crystal grains are coarse. It has become. Therefore, chipping resistance is poor.
以下、本発明について実施例によって具体的に説明する。
表１の成分組成の金属粉末をガスアトマイズ法で作製し、５００μｍ以下の篩目にて分級し、直径２３５ｍｍ、長さ１００ｍｍの缶に充填し、これを表１に示すＨＩＰ条件にて焼結し、その後、表１に示す条件で大気炉で熱処理を行ったものと、ＨＩＰ成形ままの固化成形体を作製した。それを約１０７５℃に加熱して３０ｍｍ径に鍛造加工した後１１９０℃焼入れてから５６０℃で３回焼き戻し処理を行った。耐摩耗性、靱性の評価は、上記の熱処理品をホブへ加工し、このホブを使って切削加工を施すことにより評価した。
Hereinafter, the present invention will be specifically described with reference to examples.
Metal powders having the composition shown in Table 1 were prepared by gas atomization method, classified by a sieve size of 500 μm or less, filled into a can having a diameter of 235 mm and a length of 100 mm, and sintered under the HIP conditions shown in Table 1. Then, what was heat-processed with the atmospheric furnace on the conditions shown in Table 1, and the solidification molded object as HIP shaping | molding were produced. It was heated to about 1075 ° C. and forged to a diameter of 30 mm, quenched at 1190 ° C., and then tempered three times at 560 ° C. The evaluation of wear resistance and toughness was performed by processing the heat-treated product into a hob and performing cutting using the hob.
耐摩耗性は被削材としてＳＣＭ４１５を用い、乾式で１分当たりの周速が３００ｍの切削速度で１時間切削した時の摩耗量により評価した。また、その時のチッピングの有無で靱性を評価した。汎用粉末高速度工具鋼（表Ｎｏ．１１）と比較しその結果を表１に示す。なお、炭化物としては、縦２０ｍｍ、横２０ｍｍ、長さ１０ｍｍの角棒を切出し、湿式研磨、ピクラル腐食を行い、光学顕微鏡にてミクロ組織を１０００倍で観察した時、１００μｍ2 の範囲内に存在する炭化物を画像解析ソフトを用いて円相当径を算出し、炭化物の最大径、２〜１０μｍの粗大炭化物の面積率、２μｍ未満の微細炭化物の面積率を評価した。 The wear resistance was evaluated based on the amount of wear when SCM415 was used as a work material and the cutting speed was 1 hour at a cutting speed of 300 m at a peripheral speed per minute. Further, the toughness was evaluated by the presence or absence of chipping at that time. The results are shown in Table 1 in comparison with general-purpose powder high-speed tool steel (Table No. 11). In addition, as carbide, a 20 mm long, 20 mm wide, 10 mm long square bar is cut out, wet-polished, picral corrosion is performed, and when the microstructure is observed with an optical microscope at a magnification of 1000 times, it exists in the range of 100 μm 2. The equivalent circle diameter of the carbide to be calculated was calculated using image analysis software, and the maximum carbide diameter, the area ratio of coarse carbide of 2 to 10 μm, and the area ratio of fine carbide of less than 2 μm were evaluated.
表１に示すように、比較例Ｎｏ．１１は、最大炭物径が小さく、微細炭化物の面積率が多く、かつ粗大炭化物の面積率が０のため、耐摩耗性が劣る。比較例Ｎｏ．１２は、成分組成においてＣ、Ｍｏ、Ｗ，Ｖ，Ｃｏ含有量が高く、最大炭化物径が大きく、微細炭化物の面積率が少なく、かつ粗大炭化物の面積率が多いために、チッピング性が悪い。比較例Ｎｏ．１３は、成分組成においてＣ、Ｓｉ、Ｍｎ含有量が高く、Ｖ含有量が低く、最大炭化物径が大きく、微細炭化物の面積率が少なく、かつ粗大炭化物の面積率が多いために、チッピング性が悪く、かつ耐摩耗性がやや劣る。 As shown in Table 1, Comparative Example No. No. 11 has a small maximum carbide diameter, a large area ratio of fine carbides, and an area ratio of coarse carbides of 0, resulting in poor wear resistance. Comparative Example No. No. 12 has a high C, Mo, W, V, and Co content in the component composition, a large maximum carbide diameter, a small area ratio of fine carbides, and a large area ratio of coarse carbides, and therefore has poor chipping properties. Comparative Example No. 13 has a high C, Si, Mn content, a low V content, a large maximum carbide diameter, a small area ratio of fine carbides, and a large area ratio of coarse carbides. Bad and slightly inferior in wear resistance.
比較例Ｎｏ．１４は、成分組成においてＣ，Ｓｉ，Ｍｎ，Ｃｒ，Ｍｏ，Ｗ，Ｖ含有量が低く、かつ粗大炭化物の面積率が少ないために、耐摩耗性が劣る。比較例Ｎｏ．１５は、成分組成においてＣ，Ｃｒ，Ｍｏ，Ｗ，Ｃｏ含有量が高く、Ｍｎ，Ｖ含有量が低く、かつ粗大炭化物の面積率が少ないために、耐摩耗性が劣る。これに対して、本発明であるＮｏ．１〜１０は、いずれも成分組成、ＨＩＰ条件で作製し、炭化物最大径、面積率を制御して粗大炭化物と微細炭化物が混在する組織に制御しているため耐摩耗性が向上し、耐チッピング性に優れていることが分かる。 Comparative Example No. No. 14 has a low content of C, Si, Mn, Cr, Mo, W, and V in the component composition, and the area ratio of coarse carbides is small, so that the wear resistance is inferior. Comparative Example No. No. 15 has a high C, Cr, Mo, W, Co content, a low Mn, V content, and a small area ratio of coarse carbides, so that the wear resistance is inferior. On the other hand, No. which is the present invention. Nos. 1 to 10 are manufactured under the component composition and HIP conditions, and the maximum diameter and area ratio of carbide are controlled to control the structure in which coarse carbides and fine carbides are mixed, thereby improving wear resistance and chipping resistance. It turns out that it is excellent in property.
以上述べたように、本発明による高速切削用途の粉末高速度鋼の成分組成と組織中の炭化物を適切に制御することにより、チッピング性と耐摩耗性を兼ね備えた高速度粉末工具鋼を提供することができる極めて優れた効果を奏するものである。
特許出願人 山陽特殊製鋼株式会社
代理人 弁理士 椎 名 彊
As described above, the high-speed powder tool steel having both chipping property and wear resistance is provided by appropriately controlling the composition of the powder high-speed steel for high-speed cutting use according to the present invention and the carbide in the structure. It has an extremely excellent effect.
Patent Applicant Sanyo Special Steel Co., Ltd.
Attorney: Attorney Shiina
Claims (4)
Ｃ：１．０〜１．８％、
Ｓｉ：０．１〜１．０％、
Ｍｎ：０．１〜１．０％、
Ｃｒ：２．０〜７．０％、
Ｍｏ：２．０〜７．０％、
Ｗ：３．０〜１５．０％、
Ｖ：２．０〜５．０％、
を含有し、残部Ｆｅおよび不可避的不純物よりなる鋼粉末を固化成形後、鍛造または圧延により熱間加工後、焼入、焼戻したミクロ組織において１００μｍ2中の炭化物径（円相当径）の最大値が２〜１０μｍの範囲にあり、さらに、炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％、２μｍ未満の微細炭化物の面積率が３〜１０％であることを特徴とする耐摩耗性に優れた粉末高速度工具鋼。 % By mass
C: 1.0-1.8%,
Si: 0.1 to 1.0%,
Mn: 0.1 to 1.0%,
Cr: 2.0-7.0%,
Mo: 2.0-7.0%,
W: 3.0-15.0%,
V: 2.0-5.0%,
The maximum value of the carbide diameter (equivalent circle diameter) in 100 μm 2 in a microstructure that has been solidified and then hot worked by forging or rolling, quenched, and tempered after the steel powder comprising Fe and the inevitable impurities is contained. In the range of 2 to 10 μm, the area ratio of coarse carbide with a carbide diameter of 2 to 10 μm is 2 to 10%, and the area ratio of fine carbide with a diameter of less than 2 μm is 3 to 10%. Powdered high-speed tool steel with excellent wear characteristics.
Ｃ：１．０〜１．８％、
Ｓｉ：０．１〜１．０％、
Ｍｎ：０．１〜１．０％、
Ｃｒ：２．０〜７．０％、
Ｍｏ：２．０〜７．０％、
Ｗ：３．０〜１５．０％、
Ｖ：２．０〜５．０％、
Ｃｏ：１０．０％以下
を含有し、残部Ｆｅおよび不可避的不純物よりなる鋼粉末を固化成形後、鍛造または圧延により熱間加工後、焼入、焼戻したミクロ組織において１００μｍ2中の炭化物径（円相当径）の最大値が２〜１０μｍの範囲にあり、さらに、炭化物径が２〜１０μｍの粗大炭化物の面積率が２〜１０％、２μｍ未満の微細炭化物の面積率が３〜１０％であることを特徴とする耐摩耗性に優れた粉末高速度工具鋼。 % By mass
C: 1.0-1.8%,
Si: 0.1 to 1.0%,
Mn: 0.1 to 1.0%,
Cr: 2.0-7.0%,
Mo: 2.0-7.0%,
W: 3.0-15.0%,
V: 2.0-5.0%,
Co: containing 10.0% or less, after solidifying and molding a steel powder of balance of Fe and unavoidable impurities, after hot working by forging or rolling, quenching, carbide diameter of 100μm 2 in tempered microstructure ( The maximum value of the equivalent circle diameter) is in the range of 2 to 10 μm, and the area ratio of coarse carbide with a carbide diameter of 2 to 10 μm is 2 to 10%, and the area ratio of fine carbide with a diameter of less than 2 μm is 3 to 10%. A high-powder high-speed tool steel with excellent wear resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2014034797A JP6345945B2 (en) | 2014-02-26 | 2014-02-26 | Powdered high-speed tool steel with excellent wear resistance and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2014034797A JP6345945B2 (en) | 2014-02-26 | 2014-02-26 | Powdered high-speed tool steel with excellent wear resistance and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2015160957A JP2015160957A (en) | 2015-09-07 |
| JP6345945B2 true JP6345945B2 (en) | 2018-06-20 |
Family
ID=54184282
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2014034797A Active JP6345945B2 (en) | 2014-02-26 | 2014-02-26 | Powdered high-speed tool steel with excellent wear resistance and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6345945B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111054411B (en) * | 2019-10-30 | 2022-10-21 | 中山大学 | Preparation method of multi-metal carbide electrocatalyst |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01240636A (en) * | 1988-03-18 | 1989-09-26 | Sumitomo Metal Ind Ltd | Tool having excellent surface treatability and its manufacture |
| JP2725333B2 (en) * | 1988-12-27 | 1998-03-11 | 大同特殊鋼株式会社 | Powder high speed tool steel |
| JPH02182867A (en) * | 1989-01-06 | 1990-07-17 | Daido Steel Co Ltd | Powdered tool steel |
| JPH05209255A (en) * | 1992-01-29 | 1993-08-20 | Daido Steel Co Ltd | High speed tool steel and composite |
| JP2972032B2 (en) * | 1992-06-16 | 1999-11-08 | 株式会社クボタ | High speed steel based sintered alloy |
| JP2003313642A (en) * | 2002-04-23 | 2003-11-06 | Nippon Koshuha Steel Co Ltd | Steel for high-speed tool and manufacturing method therefor |
| EP2662166A1 (en) * | 2012-05-08 | 2013-11-13 | Böhler Edelstahl GmbH & Co KG | Material with high wear resistance |
-
2014
- 2014-02-26 JP JP2014034797A patent/JP6345945B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2015160957A (en) | 2015-09-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6410515B2 (en) | Nitride powder high-speed tool steel excellent in wear resistance and method for producing the same | |
| TWI654318B (en) | High speed tool steel and manufacturing method thereof | |
| JP2008169411A (en) | Steel for die materials | |
| EP3315617B1 (en) | Method for producing high-speed tool steel material, method for producing high-speed tool steel product, and high-speed tool steel product | |
| JP2017043814A (en) | Die steel and die | |
| JP2009013439A (en) | High toughness high-speed tool steel | |
| WO2012118053A1 (en) | Hot work tool steel having excellent toughness, and process of producing same | |
| JP5029942B2 (en) | Hot work tool steel with excellent toughness | |
| JP6710484B2 (en) | Powder high speed tool steel | |
| JP2019019397A (en) | Preharden hot tool steel excellent in machinability | |
| JP6096040B2 (en) | Powdered high-speed tool steel with excellent high-temperature tempering hardness | |
| JP6345945B2 (en) | Powdered high-speed tool steel with excellent wear resistance and method for producing the same | |
| JP2005336553A (en) | Hot tool steel | |
| JP5212772B2 (en) | Hot work tool steel with excellent toughness and high temperature strength | |
| JP2020050917A (en) | Martensitic stainless steel for high hardness and high corrosion resistant applications, excellent in cold workability, and manufacturing method therefor | |
| JP4322239B2 (en) | Cold tool steel and manufacturing method thereof | |
| WO2020084352A1 (en) | A method of producing a high speed steel alloy | |
| KR102356521B1 (en) | Uniform steel alloys and tools | |
| JP6359241B2 (en) | Corrosion-resistant plastic molding steel with excellent specularity | |
| JP5907416B2 (en) | Method for producing hot work tool steel with excellent toughness | |
| JP6312120B2 (en) | Powdered high speed tool steel and manufacturing method thereof | |
| JP3894373B2 (en) | High hardness and corrosion resistant steel for blades | |
| KR100502193B1 (en) | High speed tool steel having superior hardness and method for manufacturing the same | |
| JPH0711377A (en) | Production of sintered tool steel | |
| JP2000273590A (en) | Cast steel for heat treatment, excellent in weldability and machinability |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20170116 |
|
| RD03 | Notification of appointment of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7423 Effective date: 20171020 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20171122 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20171128 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20180111 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20180522 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20180524 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6345945 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |