JP2006312767A

JP2006312767A - Surface treatment method for imparting abrasion resistance and oxidation resistance to steel member

Info

Publication number: JP2006312767A
Application number: JP2005135921A
Authority: JP
Inventors: Keizo Tsukamoto; 塚本恵三; Hiroaki Wakayama; 若山宏明; Minoru Fumoto; 稔麓
Original assignee: AYABO KK
Current assignee: AYABO KK
Priority date: 2005-05-09
Filing date: 2005-05-09
Publication date: 2006-11-16

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a surface treatment process for imparting oxidation resistance and abrasion resistance to a steel member such as a shaped member and a cutting tool requires a high material cost, because the substrate material for the steel member needs to have high hardness, and consequently needs to employ a high alloy steel such as SKH-51 which is a tool steel, or a hard metal. <P>SOLUTION: The method for manufacturing the steel member which employs an inexpensive low alloy for the substrate material and is provided with the abrasion resistance and the oxidation resistance comprises the steps of: using the low alloy like carbon steel or malleable cast iron, as the substrate material; forming a film containing a Ti-Al-N, Al-Cr-N or Al-Cr-Si-N film in the outermost layer, which has the oxidation resistance and the heat resistance at a quenching temperature for the substrate material or at a higher temperature, by an arc-type ion plating technique; and quenching a necessary portion to be given the abrasion resistance by local heat treatment such as flame hardening. The surface treatment method for imparting heat resistance and oxidation resistance to the low alloy includes forming a film durable to hardening heat treatment to be performed on the substrate material having the film already formed on the surface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、物理蒸着法を用いた、基板材の材質に関わらず優れた耐摩耗性、耐酸化性を得る鉄鋼製部材の表面処理方法に関する。 The present invention relates to a surface treatment method for a steel member using physical vapor deposition to obtain excellent wear resistance and oxidation resistance regardless of the material of a substrate material.

鉄鋼製部材の耐酸化性にすぐれた表面処理方法としては、Al-Cr-N系複合硬質皮膜をイオンプレーティングにより基板上に形成する方法が示されている(例えば、特許文献１参照) 。また、耐酸化性、耐摩耗性に優れた表面処理方法として、被処理物の外側表面にAl, Cr及びSiを主成分とする窒化物からなるコーティング層と、該コーティング層と該被処理物の間にTi又はCrの窒化物からなる下地層と、該コーティング層と該下地層との界面に設けられる中間層であって該中間層に接する前記コーティング層と前記下地層の組成成分を含む中間層とを備えることを特徴とする高硬度皮膜が開示されている(例えば、特許文献２参照) 。 As a surface treatment method excellent in oxidation resistance of steel members, a method of forming an Al—Cr—N based composite hard film on a substrate by ion plating is shown (for example, see Patent Document 1). Further, as a surface treatment method excellent in oxidation resistance and wear resistance, a coating layer made of a nitride mainly composed of Al, Cr and Si on the outer surface of the object to be processed, the coating layer and the object to be processed Including an underlayer made of a nitride of Ti or Cr, and an intermediate layer provided at an interface between the coating layer and the underlayer, the coating layer being in contact with the intermediate layer, and a composition component of the underlayer A high-hardness film comprising an intermediate layer is disclosed (for example, see Patent Document 2).

特開平１０-２５５６６号公報JP-A-10-25566 特開２００５-４２１４６号公報JP 2005-42146 A

従来の耐酸化性、耐摩耗性に優れた表面処理方法では、基板材の最終熱処理後に表面処理を行っていた。このため、基板材の表面部は該表面処理の温度で焼鈍された状態となるので、基板材には工具鋼のような焼鈍状態でも高い硬度を有する高合金を使用することが必要であった。実際に、例えば特開平１０−２５５６６の例では工具鋼であるSKH-51を母材に用いた例が開示されており、特開２００５―４２１４６においてもやはりSKH-51や超硬合金であるTH10を母材として用いた例が開示されており、基板材の材料コストの点から大きな課題であった。 In the conventional surface treatment method excellent in oxidation resistance and wear resistance, the surface treatment is performed after the final heat treatment of the substrate material. For this reason, since the surface part of the board | substrate material will be in the state annealed by the temperature of this surface treatment, it was necessary to use the high alloy which has high hardness also in an annealing state like tool steel for a board | substrate material. . Actually, for example, in the example of Japanese Patent Laid-Open No. 10-25566, an example in which SKH-51 which is a tool steel is used as a base material is disclosed, and also in Japanese Patent Application Laid-Open No. 2005-42146, TH10 which is also SKH-51 or cemented carbide. An example in which is used as a base material is disclosed, which is a big problem in terms of the material cost of the substrate material.

本発明者らは上記の課題に鑑み、耐酸化、耐摩耗性に優れた鉄鋼製部材の新たな製造工程を確立することにより、例えば鋳造用材料として用いられている可鍛鋳鉄や炭素鋼のような低合金を基板材として使用し、目的の性質を得て材料コストの大幅な低減を達成する方法を鋭意研究を行った結果、本発明を完成するに至ったものである。 In view of the above problems, the present inventors have established a new manufacturing process for steel members having excellent oxidation resistance and wear resistance. For example, the present invention can be applied to malleable cast iron and carbon steel used as a casting material. As a result of intensive studies on a method of using such a low alloy as a substrate material and obtaining a desired property to achieve a significant reduction in material cost, the present invention has been completed.

すなわち、本発明の骨子とするところは、可鍛鋳鉄や炭素鋼のような低合金を基板材に用いて、母材の焼き入れ温度以上の耐酸化性、耐熱性を有する皮膜をPVD処理により基板材表面に形成させることにより、通常の製造工程とは逆にPVD処理による皮膜形成のあとに母材の耐摩耗性を要する部分に火炎焼入れ等の局部的熱処理を施し、母材の硬さを上昇させ、かつ局部的な焼き入れ加熱により熱処理歪も小さい状態で所要の耐摩耗性を付与しようとするものである。 That is, the main point of the present invention is that a low alloy such as malleable cast iron or carbon steel is used as a substrate material, and a film having oxidation resistance and heat resistance higher than the quenching temperature of the base material is obtained by PVD treatment. By forming it on the surface of the substrate material, a local heat treatment such as flame quenching is applied to the part that requires wear resistance of the base material after film formation by PVD processing, contrary to the normal manufacturing process, and the hardness of the base material The required wear resistance is imparted in a state where the heat treatment strain is small by local quenching heating.

本発明により、プレス金型や切削工具等の鉄鋼製の耐摩耗性を必要とする部材を製作する場合に、工具鋼のような高合金鋼や超硬合金を用いず炭素鋼や可鍛鋳鉄のような低合金を基板材料として用い、耐熱性、耐酸化性に優れた耐摩耗表面処理を行った後、基板材料の必要部分に火炎焼き入れのような局部的硬化熱処理を行うことにより所要の耐摩耗性を付与することができ、基板材料の大幅なコスト低減が可能となった。 According to the present invention, when manufacturing a steel member that requires wear resistance such as a press die or a cutting tool, carbon steel or malleable cast iron is used without using high alloy steel or cemented carbide such as tool steel. It is necessary to use a low alloy such as, as a substrate material, and after performing a wear-resistant surface treatment with excellent heat resistance and oxidation resistance, a necessary part of the substrate material is subjected to a local hardening heat treatment such as flame quenching. Thus, the cost of the substrate material can be greatly reduced.

請求項に基づいて、本発明の実施の形態について説明を行う。これまでの耐摩耗性、耐酸化性を要する鉄鋼製部材の製造手段としては、例えばSKD-51のような工具鋼を基板材として用い、基板材を調質処理してHRc50以上の高い硬度にした後、ＰＶＤ処理により表面にTi-Al--N系又はAl-Cr--N系又はAl-Cr-Si-N系複合硬質皮膜を最外層にもつ皮膜をコーティングすること等により所要の耐摩耗性を達成している。 Based on the claims, embodiments of the present invention will be described. As a conventional means of manufacturing steel members that require wear resistance and oxidation resistance, for example, tool steel such as SKD-51 is used as a substrate material, and the substrate material is tempered to a high hardness of HRc 50 or higher. After that, the PVD treatment is applied to the surface by coating with a Ti-Al--N-based, Al-Cr--N-based, or Al-Cr-Si-N-based composite hard coating as the outermost layer. Abrasion is achieved.

本発明においては、請求項1及び２に述べているように、基板材料として工具鋼のような高合金鋼を用いることなく、例えば可鍛鋳鉄や炭素鋼のような低合金を用いて、基板材料の硬化熱処理温度（８００〜９５０℃）以上の耐熱性、耐酸化性を有する皮膜を基板材料表面にコーティング後、基板材のうちの耐摩耗性を要する部分に例えば火炎焼入れのような局部的表面硬化処理を行うことにより、所要の耐摩耗性を達成する。 In the present invention, as described in claims 1 and 2, without using a high alloy steel such as tool steel as a substrate material, a low alloy such as malleable cast iron or carbon steel is used. After coating the surface of the substrate material with a film having heat resistance and oxidation resistance higher than the heat treatment temperature (800 to 950 ° C.) of the material, the portion of the substrate material that requires wear resistance is localized such as flame quenching. The required wear resistance is achieved by performing a surface hardening treatment.

所要の耐熱性、耐酸化性を有するコーティング材料としては、請求項３に示しているように、最表面部がTi-Al-N系又はAl-Cr-N系又はAl-Cr-Si-N系である皮膜が基板材料の硬化熱処理温度以上の耐熱性、耐酸化性を有し、なおかつ耐摩耗性にも優れており、コーティング後に基板材に対し局部的な表面硬化処理を行った場合にも、皮膜が損傷を受けることがなく好適である。 As a coating material having required heat resistance and oxidation resistance, as shown in claim 3, the outermost surface portion is Ti—Al—N, Al—Cr—N, or Al—Cr—Si—N. When the coating that is a system has heat resistance and oxidation resistance higher than the curing heat treatment temperature of the substrate material, and also has excellent wear resistance, when the substrate material is subjected to local surface curing treatment after coating However, it is preferable that the film is not damaged.

請求項4に示すように、基板材料の硬化熱処理温度以上の耐熱性、耐酸化性を有し、なおかつ耐摩耗性にも優れている被膜を表面にコーティングすることにより、硬化表面処理後に部材の必要部位に火炎焼き入れ等の局部的熱処理を施すことにより、可鍛鋳鉄あるいは炭素鋼のような低合金を基板材として用いた耐摩耗性に優れた鉄鋼部材の製造が可能である。 As shown in claim 4, by coating the surface with a film having heat resistance and oxidation resistance equal to or higher than the curing heat treatment temperature of the substrate material and excellent in wear resistance, By performing a local heat treatment such as flame quenching on a required part, it is possible to manufacture a steel member having excellent wear resistance using a low alloy such as malleable cast iron or carbon steel as a substrate material.

また、コーティング方法としては請求項５に示したように、アーク式イオンプレーティング法のPVD処理によるコーティングが皮膜の密着性や作業性の面から好適である。 As a coating method, as described in claim 5, coating by PVD treatment using an arc ion plating method is preferable from the viewpoint of film adhesion and workability.

アーク式イオンプレーティング装置を用いて、SKD-51及び可鍛鋳鉄、及び炭素鋼の基板材に対しTi-Al-Si-N系、Al-Cr-N系、Al-Cr-Si-N系、Ti-N系、TiCN系及びTi-C系の皮膜が最外層となる皮膜を形成した。皮膜の厚みはそれぞれ５−７μmである。皮膜の形成後、部材の耐摩耗性必要個所に火炎焼入れを施した。この時の加熱温度は８００-９５０℃とした。火炎焼入れ後、皮膜硬さ及び基板材の最表面硬さを測定した。この結果を、PVD処理前の基板材の硬さと合わせて表１に示す。 Ti-Al-Si-N, Al-Cr-N, Al-Cr-Si-N for SKD-51, malleable cast iron, and carbon steel substrates using arc ion plating equipment Ti-N, TiCN and Ti-C films were formed as the outermost layers. The thickness of each film is 5-7 μm. After the formation of the film, flame quenching was applied to the parts where the wear resistance of the member was required. The heating temperature at this time was 800-950 ° C. After flame quenching, the film hardness and the outermost surface hardness of the substrate material were measured. The results are shown in Table 1 together with the hardness of the substrate material before PVD processing.

本発明例であるNo.1-No.4は、火炎焼入れ後にもPVD処理による皮膜が正常に維持されており、Hv2500程度の硬さを示しているのに対し、比較例であるNo.5-No.7では火炎焼入れ時の加熱により皮膜が剥離しており、表面部の硬さは母材の硬さとなっていることがわかった。 No.1-No.4 which is an example of the present invention, the film by PVD treatment is normally maintained even after flame quenching, and shows a hardness of about Hv2500, whereas No.5 which is a comparative example -In No.7, the film was peeled off by heating during flame quenching, and the hardness of the surface was found to be that of the base material.

火炎焼入れ後の各試験片に対し、耐摩耗性を評価するためアルミナボール（径６）を使用したボールオンディスク摩耗試験を実施した。試験条件は、荷重５Ｎ、すべり速度１２０ｍ／秒、摺動距離３００ｍ、室温、無潤滑とした。摩耗量の測定は、摩耗試験後の試験片表面の摩耗深さ及び摩耗幅を測定することにより行った。また、熱処理及び表面処理後の熱処理歪を測定するため、ドリルチップ形状の試験片に表１に示す１〜７の条件で熱処理及びPVD処理を行い、処理後のドリルチップの寸法測定により熱処理歪の大小を判定した。 A ball-on-disk wear test using alumina balls (diameter 6) was performed on each test piece after flame quenching in order to evaluate the wear resistance. The test conditions were a load of 5 N, a sliding speed of 120 m / sec, a sliding distance of 300 m, room temperature, and no lubrication. The amount of wear was measured by measuring the wear depth and wear width on the surface of the test piece after the wear test. In addition, in order to measure heat treatment strain after heat treatment and surface treatment, heat treatment and PVD treatment are performed on the drill tip-shaped test piece under the conditions 1 to 7 shown in Table 1, and heat treatment strain is measured by measuring the dimensions of the drill tip after treatment. Judged the size of.

表２に、ボールオンディスク摩耗試験及び熱処理歪の結果を示す。本発明例であるNo.1−No.4の試験における摩耗量は、比較例であるNo.5−No.7に比較して摩耗深さおよび摩耗幅がいずれも少なく耐摩耗性に優れており、また熱処理歪も小さいことが判明した。また、基板材として炭素鋼あるいは可鍛鋳鉄を用いたNo.1〜 No.3と、SKD-51を用いたNo.4との間にも摩耗試験結果に顕著な差は認められず、本発明によれば基板材料としてSKD-51のような工具鋼を用いず、より安価な炭素鋼あるいは可鍛鋳鉄を用いても所要の耐摩耗性が達成されており、基板材料の低合金化による大幅なコストダウンが可能であることが明らかとなった。 Table 2 shows the results of the ball-on-disk wear test and heat treatment strain. The amount of wear in the test of No.1-No.4, which is an example of the present invention, is less in wear depth and wear width than the comparative example No.5-No.7 and has excellent wear resistance. It was also found that the heat treatment strain was small. In addition, there is no significant difference in wear test results between No. 1 to No. 3 using carbon steel or malleable cast iron as a substrate material and No. 4 using SKD-51. According to the invention, the required wear resistance is achieved even if cheaper carbon steel or malleable cast iron is used without using tool steel such as SKD-51 as the substrate material. It became clear that a significant cost reduction was possible.

Claims

耐摩耗性を必要とする鉄鋼製部材の表面硬化処理において、表面部に、耐熱性、耐酸化性に優れ、かつ室温での耐摩耗性にすぐれた皮膜を形成したあと、基材の耐摩耗性必要部分に火炎焼入れ等の局部的な表面硬化熱処理を施すことにより、基材の材質にかかわらず、熱処理歪が小さく、母材の靭性を損なうことなく優れた耐摩耗性、耐酸化性を得る鉄鋼製部材の表面処理方法。 In the surface hardening treatment of steel parts that require wear resistance, after forming a film with excellent heat resistance and oxidation resistance on the surface and excellent wear resistance at room temperature, wear resistance of the base material By applying local surface hardening heat treatment such as flame quenching to the necessary properties, heat treatment distortion is small regardless of the material of the base material, and excellent wear resistance and oxidation resistance without impairing the toughness of the base material A surface treatment method for a steel member to be obtained.

請求項１の表面硬化処理において、最表面部に形成される皮膜が基材の焼き入れ温度より高い温度での耐熱性、耐酸化性を有し、常温での耐摩耗性に優れた被膜であることを特徴とする、優れた耐摩耗性、耐酸化性を得る鉄鋼製部材の表面処理方法。 In the surface hardening process of Claim 1, the film formed in the outermost surface part has heat resistance and oxidation resistance at a temperature higher than the quenching temperature of the substrate, and is a film excellent in wear resistance at room temperature. A method for treating a surface of a steel member that has excellent wear resistance and oxidation resistance.

請求項１又は２の表面硬化処理において、最表面部に形成される皮膜がTi-Al-N系又はAl-Cr-N系又はAl-Cr-Si-N系の耐熱性、耐酸化性、耐摩耗性に優れた皮膜であることを特徴とする耐摩耗性、耐酸化性に優れた鉄鋼製部材の表面処理方法。 In the surface hardening treatment according to claim 1 or 2, the film formed on the outermost surface part is a Ti-Al-N-based, Al-Cr-N-based, or Al-Cr-Si-N-based heat resistance, oxidation resistance, A surface treatment method for a steel member having excellent wear resistance and oxidation resistance, characterized by being a film having excellent wear resistance.

普通鋼や可鍛鋳鉄のような低合金を用いて製作された鉄鋼製部材に、硬化表面処理後に基板材の硬化熱処理を行うために実施される、請求項1又は２又は３に記載の表面処理サービス。 The surface according to claim 1, 2 or 3, which is carried out for performing a heat treatment of the substrate material after the hardened surface treatment on a steel member manufactured using a low alloy such as ordinary steel or malleable cast iron. Processing service.

請求項１又は２又は３の表面硬化処理において、表面皮膜の形成方法がアーク式イオンプレーティングによるPVD処理であることを特徴とする耐摩耗性、耐酸化性に優れた鉄鋼製部材の表面処理方法。
The surface treatment of a steel member having excellent wear resistance and oxidation resistance, characterized in that the surface film is formed by PVD treatment using arc ion plating in the surface hardening treatment according to claim 1, 2 or 3. Method.