BEARING PORTION FOR CHAIN, PIN, ITS MANUFACTURING METHOD, AND CHAIN USING THE SAME

摘要

PROBLEM TO BE SOLVED: To solve a problem on increase of early abrasion of a bearing portion under severe environment of poor lubrication in a chain composed of a pin having a vanadium carbide coating film.SOLUTION: At least one of members configuring a bearing portion for a chain, for example, a pin includes a surface layer composed of a vanadium carbonitride (VCN) coating film obtained by adding and dissolving high functional element such as Ti, Si, Mo and the like to a surface of a base material. An oxide coating film of a prescribed thickness is formed on a surface of the surface layer. A VO coating film can be prevented from being excessively formed by a VCN-(Ti, Si, Mo) coating film even under a severe environment. By the solid solution of the high functional element (for example, Mo), an applicable and acceptable range of N content can be expanded.SELECTED DRAWING: Figure 12