# US 8,783,006 B2 · Chain and manufacturing method of sliding member of the chain > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,006 B2 - Document ID: US8783006B2 - Status: Granted - Kind: B2 - Application number: 14/078,885 - Filed: 2013-11-13 - Published: 2014-05-22 - Granted: 2014-07-22 - Earliest claimed: 2012-11-16 - Assignees: Daido Kogyo Co., Ltd. - Applicants: Daido Kogyo Co., Ltd. - Inventors: Jun Baba - Web page: https://patentgrep.com/patent/US8783006B2 ## CPC - F16G 13/06: with links connected by parallel driving-pins with or without rollers {so-called open links} - C21D 1/06: Surface hardening - C21D 9/0087: {for chains, for chain links} - C23C 8/26: of ferrous surfaces - C21D 2211/008: Martensite - F16G: BELTS, CABLES, OR ROPES, PREDOMINANTLY USED FOR DRIVING PURPOSES; CHAINS; FITTINGS PREDOMINANTLY USED THEREFOR - 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 chain includes a plurality of sliding members that moves relative to each other. At least one of sliding members is formed of a martensitic stainless steel, and contains, in a superficial layer thereof, elemental substances of carbon and nitrogen at a range from 0.17 to 0.50 mass % in total, while a precipitation amount of carbide and nitride is 0.05 mass % or less in total. ## Claims ### Claim 1 A chain comprising: a plurality of sliding members that moves relative to each other, at least one of which is formed of a martensitic stainless steel, and contains, in a superficial layer thereof, elemental substances of carbon and nitrogen at a range from 0.17 to 0.50 mass % in total, while a precipitation amount of carbide and nitride is 0.05 mass % or less in total. ### Claim 2 (depends on 1) The chain according to claim 1, wherein the martensitic stainless steel includes a base material portion which containing carbon in a range from 0.02 to 0.3 mass % and exists in an inner side of the superficial layer. ### Claim 3 (depends on 2) The chain according to claim 2, further comprising a plurality of link plates, wherein the sliding members includes pins that bendably link the plurality of link plates, and wherein each one of all the sliding members and the plurality of the link plates is made of stainless steel. ### Claim 4 (depends on 1) The chain according to claim 1, further comprising: a plurality of outer link plates; and a plurality of inner link plates, wherein the sliding members include pins by which a pair of the outer link plates is linked at both end portions, thereby to form an outer link; and bushings by which a pair of the inner link plates is linked at both end portions, thereby to form an inner link, and through which the corresponding pins are inserted, thereby to alternatively link the outer links and the inner links, and wherein the pins and the bushings are included in the at least one of the sliding members. ### Claim 5 (depends on 3) The chain according to claim 3, wherein the plurality of the link plates includes: a plurality of outer link plates; and a plurality of inner link plates, wherein the sliding members include: pins by which a pair of the outer link plates is linked at both end portions, thereby to form an outer link; and bushings by which a pair of the inner link plates is linked at both end portions, thereby to form an inner link, and through which the corresponding pins are inserted, thereby to alternatively link the outer links and the inner links, and wherein the pins and the bushings are included in the at least one of the sliding members. ### Claim 6 (depends on 4) The chain according to claim 4, wherein the sliding members include rollers that enclose the corresponding bushings, and wherein the rollers are included in the sliding members. ### Claim 7 (depends on 5) The chain according to claim 5, wherein the sliding members include rollers that enclose the corresponding bushings, and wherein the rollers are included in the sliding members. ### Claim 8 (depends on 4) The chain according to claim 4, wherein the outer link plates and the inner link plates are made of austenitic stainless steel. ### Claim 9 (depends on 6) The chain according to claim 6, wherein the outer link plates and the inner link plates are made of austenitic stainless steel. ### Claim 10 (depends on 7) The chain according to claim 7, wherein the outer link plates and the inner link plates are made of austenitic stainless steel. ### Claim 11 A chain comprising: a plurality of link plates; and pins that bendably link the link plates, wherein the pins are formed of a martensitic stainless steel, and contains, in a superficial layer thereof, elemental substances of carbon and nitrogen at a range from 0.17 to 0.50 mass % in total, while a precipitation amount of carbide and nitride is 0.05 mass % or less in total. ### Claim 12 (depends on 11) The chain according to claim 11, further comprising bushings that enclose the corresponding pins thereby to link links formed by linking the link plates, wherein the bushings are formed of a martensitic stainless steel, and contains, in a superficial layer thereof, elemental substances of carbon and nitrogen at a range from 0.17 to 0.50 mass % in total, while a precipitation amount of carbide and nitride is 0.05 mass % or less in total. ### Claim 13 (depends on 11) The chain according to claim 11, further comprising rollers that enclose the corresponding bushings, wherein the rollers are formed of a martensitic stainless steel, and contains, in a superficial layer thereof, elemental substances of carbon and nitrogen at a range from 0.17 to 0.50 mass % in total, while a precipitation amount of carbide and nitride is 0.05 mass % or less in total. ### Claim 14 (depends on 11) The chain according to claim 11, wherein the link plates are formed of a martensitic stainless steel, and contains, in a superficial layer thereof, elemental substances of carbon and nitrogen at a range from 0.17 t 0.50 mass % in total, while a precipitation amount of carbide and nitride is 0.05 mass % or less in total. ### Claim 15 A manufacturing method of a sliding member of a chain that slides against another member, the method comprising: a first evacuating step, wherein an environment around a sliding member made from martensitic stainless steel base material is evacuated; a first heating-up step, wherein a temperature of the sliding member is raised to a temperature range from 950° C. to 1050° C. after the first evacuating step; a first maintaining step, where the sliding member is maintained at a temperature range from 950° C. to 1050° C. for a period of time from 1 to 3 hours after the first hating step; a first nitrogen introducing step, wherein the environment around the sliding member is filled with nitrogen treatment gas, during a time period after the first evacuating step and before the first maintaining step; a first cooling step, wherein the sliding member is cooled by a nitrogen treatment gas to a normal temperature after the first maintaining step; a second evacuating step, wherein the environment around the sliding member is evacuated to vacuum after the first cooling step; a second heating-up step, wherein the sliding member is heated to a temperature range from 150° C. to 200° C. after the second evacuating step; a second maintaining step, wherein the sliding member is maintained at a temperature range from 150° C. to 200° C. after the second heating-up step; a second nitrogen introducing step, wherein the environment around the sliding member is filled with nitrogen treatment gas, during a time period after the second evacuating step and before the second maintaining step; and a second cooling step, wherein the sliding member is gradually cooled to a normal temperature after the second maintaining step. ### Claim 16 (depends on 15) The manufacturing method of the sliding member of the chain that slides against another member, according to claim 15, wherein the environment around the sliding member is kept at less than 20 Pa in the first evacuating step and the second evacuating step. ### Claim 17 (depends on 15) The manufacturing method of the sliding member of the chain that slides against another member, according to claim 15, wherein the sliding member formed by the martensitic stainless steel containing carbon in a range from 0.02 to 0.3 mass %.