Daido Kogyo Co., Ltd.

Honda Motor Co., Ltd.

Yoshio Okumura

Akira Fujiwara

Motoki Tanaka

Mitsuru Yasuta

Yukihiro Kishi

Masashi Nishikawa

Yuma Ohsaka

At least one member composing a chain bearing, such as a pin, includes a surface layer composed of vanadium carbonitride (VCN) coating on a surface of a base material of the at least one member. An oxide (VO) film having a predetermined thickness is also formed on a surface of the surface layer such that the oxide film is interposed between the surface layer and another member, such as a pin hole, composing the chain bearing.

Chain bearing, chain pin, and chain

There is provided a wear-resistant chain having a high durability even in severe use environments such as those of a timing chain of an engine even though it is highly efficient and productive. A miniaturizing agent containing silicon is doped in a vanadium cementation process of a base material of steel. Vanadium carbide forming a surface-hardened layer contains a secondary phase composed of an amorphous structure containing silicon within crystal grains and a crystal grain size of the vanadium carbide is miniaturized to 1 &#x3bc;m or less.

Wear-resistant chain

A chain pin manufacturing method that requires only one heat treatment step of forming a boundary part composed of (V, Cr)Cby Cr and C in a base material at first through a cementation process in a VCl atmosphere by using Cr-rich steel as the pin base material and of forming a surface layer composed of VC. A Cr content in the boundary part decreases gradually toward the base material and the surface layer and the boundary part is not clearly divided. The inventive manufacturing method is simple and enables to manufacture the pin having high abrasion resistance and suitably used in a severe environment like a timing chain.

Pin for chain and method for manufacture thereof

Growing community of inventors

Kaga, Japan

Yoshio Okumura