PIN FOR CHAIN AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To improve wear resistance of a pin for a chain under high contact pressure. SOLUTION: A carbide layer which is mainly made of vanadium carbide and contains small quantity of chromium carbide is formed on a topmost surface part of steel to be a base material of the pin for the chain. In a boundary region between the carbide layer and the base material, a boundary layer (chromium rich layer) in which contents of vanadium carbide is rapidly reduced and contents of chromium carbide is rapidly increased is formed. In this case, generation of peeling from a surface layer of the carbide layer can be prevented since the carbide layer formed on the topmost surface part of the base material is mainly made of vanadium carbide. Since the boundary layer between the carbide layer and the base material contains comparatively large quantity of chromium, coupling force of the carbide layer and the base material becomes high via the boundary layer and peeling of the carbide layer from the base material can be prevented. Thus, wear resistance of the pin can be improved also under high surface pressure.