# US 2014/0197003 A1 · Sliding member, clutch plate, and production methods thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197003 A1 - Document ID: US20140197003A1 - Status: Published application - Kind: A1 - Application number: 14/155,714 - Filed: 2014-01-15 - Published: 2014-07-17 - Earliest claimed: 2013-01-15 - Assignees: CNK Co., Ltd.; Jtekt Corporation - Applicants: CNK Co., Ltd.; JTEKT Corporation - Inventors: Hiroyuki ANDO; Junji ANDO; Takuya TSUDA; Shuichi TAKAHASHI; Kiyoyuki HATTORI; Kazuhiro FUKUSHIMA; Tomoyuki NANBA; Hiroshi SHIRAYANAGI - Web page: https://patentgrep.com/patent/US20140197003A1 ## CPC - F16D 13/64: Clutch-plates; Clutch-lamellae (brake-plates, brake-lamellae F16D65/12) - C21D 1/06: Surface hardening - C21D 1/74: Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material - C21D 7/13: by hot working - C21D 9/0068: {for particular articles not mentioned below} - C23C 8/02: Pretreatment of the material to be coated (C23C8/04 takes precedence) - C23C 8/26: of ferrous surfaces - C23C 8/34: more than one element being applied in more than one step - C23C 8/80: After-treatment - F16D 13/648: {for clutches with multiple lamellae} - C21D 1/58: Oils - C21D 9/46: for sheet metals - F16D 27/115: with more than two discs, e.g. multiple lamellae - F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) ## Abstract A sliding member includes a base material portion formed of steel; a nitrogen diffusion layer with a thickness of 10 μm to 50 μm; and a nitrogen compound layer with a thickness of 10 μm to 50 μm. The nitrogen compound layer and the nitrogen diffusion layer are formed by performing a first heating process of performing heat treatment on a material formed of steel in an ammonia atmosphere at a temperature of 570° C. to 660° C., a second heating process of performing heat treatment on the material in a non-oxidizing and non-ammonia atmosphere at a temperature of 660° C. to 690° C., the temperature in the second heating process being higher than the temperature in the first heating process, and an oil cooling process of performing oil cooling treatment at an oil temperature of 60° C. to 80° C. subsequently to the second heating process. ## Claims ### Claim 1 A sliding member comprising: a base material portion that is formed of steel; a nitrogen diffusion layer that is formed to have a thickness of 10 μm to 50 μm on a surface side of the base material portion; and a nitrogen compound layer that is formed to have a thickness of 10 μm to 50 μm on a surface side of the nitrogen diffusion layer, and that constitutes an outermost surface, wherein the nitrogen compound layer and the nitrogen diffusion layer are formed by performing a first heating process of performing heat treatment on a material formed of steel in an ammonia atmosphere at a temperature of 570° C. to 660° C., a second heating process of performing heat treatment on the material in a non-oxidizing and non-ammonia atmosphere at a temperature of 660° C. to 690° C. subsequently to the first heating process, the temperature in the second heating process being higher than the temperature in the first heating process, and an oil cooling process of performing oil cooling treatment at an oil temperature of 60° C. to 80° C. subsequently to the second heating process. ### Claim 2 (depends on 1) The sliding member according to claim 1, wherein the temperature of the atmosphere in the first heating process is equal to or higher than 590° C. ### Claim 3 (depends on 1) The sliding member according to claim 1, wherein the oil cooling process is performed in a non-oxidizing atmosphere. ### Claim 4 (depends on 1) The sliding member according to claim 1, wherein the nitrogen compound layer and the nitrogen diffusion layer are formed by further performing a tempering process of performing tempering treatment at a temperature of 250° C. to 400° C. while pressurizing a surface side of the material, subsequently to the oil cooling process. ### Claim 5 (depends on 1) The sliding member according to claim 1, wherein a heat treatment time in the second heating process is set to be shorter than a heat treatment time at the temperature of 570° C. to 660° C. in the first heating process. ### Claim 6 (depends on 1) The sliding member according to claim 1, wherein the ammonia atmosphere is maintained while temperature raising is performed from the temperature at which the heat treatment is performed in the first heating process to the temperature at which the heat treatment is performed in the second heating process. ### Claim 7 (depends on 1) The sliding member according to claim 1, wherein the ammonia atmosphere is created at an atmosphere temperature of 500° C. to 550° C. immediately before the first heating process, and then temperature raising is performed from the atmosphere temperature of 500° C. to 550° C. to the temperature at which the heat treatment is performed in the first heating process. ### Claim 8 (depends on 1) The sliding member according to claim 1, wherein oxidation treatment is performed in an oxidizing atmosphere at a temperature of 300° C. to 450° C., before the first heating process is performed. ### Claim 9 (depends on 8) The sliding member according to claim 8, wherein hot pressing treatment is performed before the oxidation treatment is performed, and in the hot pressing treatment, a pressurizing force of 5 N or more is applied to the material at a temperature of 600° C. to 700° C. ### Claim 10 (depends on 1) A clutch plate constituting an electromagnetic clutch, comprising: the sliding member according to claim 1. ### Claim 11 A method of producing a sliding member including a base material portion that is formed of steel, a nitrogen diffusion layer that is formed to have a thickness of 10 μm to 50 μm on a surface side of the base material portion, and a nitrogen compound layer that is formed to have a thickness of 10 μm to 50 μm on a surface side of the nitrogen diffusion layer, and that constitutes an outermost surface, wherein the nitrogen compound layer and the nitrogen diffusion layer are formed by performing: a first heating process of performing heat treatment on a material formed of steel in an ammonia atmosphere at a temperature of 570° C. to 660° C.; a second heating process of performing heat treatment on the material in a non-oxidizing and non-ammonia atmosphere at a temperature of 660° C. to 690° C. subsequently to the first heating process, the temperature in the second heating process being higher than the temperature in the first heating process; and an oil cooling process of performing oil cooling treatment at an oil temperature of 60° C. to 80° C. subsequently to the second heating process. ### Claim 12 (depends on 11) A method of producing a clutch plate constituting an electromagnetic clutch, comprising: the method of producing a sliding member according to claim 11.