Antiwear chain

Abstract

An antiwear chain which can be efficiently produced with excellent productivity and, despite this, has high durability even under severe use conditions as for, e.g., the timing chain of an engine. Inthe vanadium diffusion / penetration treatment of a steel base, a silicon-containing size-reducing agent is added. The vanadium carbide forming a surface-hardening layer has, in the crystal grains, a second phase comprising a silicon-containing amorphous structure. This vanadium carbide has a crystal grain diameter reduced to 1 ¢mu!m or smaller.

Description

technical field [0001] The present invention relates to transmission chains such as silent chains and roller chains. More specifically, the present invention relates to the formation of bearings that rotate relative to each other such as pin shafts and links, or pin shafts and bushes, etc. in the above chains. Vanadium carbide surface-hardened layer for wear-resistant chains. Background technique [0002] Recently, transmission chains are often used in severe conditions such as engine timing chains in high-temperature environments and repeated high surface pressures. In addition, a large amount of EGR is caused by the strengthening of exhaust gas restrictions. Whether it is a diesel engine or a gasoline engine, it is often used in a severe state such as the mixing of soot into the oil is promoted. In such a case, high durability is still required. Therefore, it is proposed to use the pin shaft as a bearing. A surface hardened layer composed of vanadium carbide (VC) is forme...

AI Technical Summary

Problems solved by technology

[0008] However, when the high-temperature treatment is performed by the conventional vanadium diffusion and infiltration treatment, the grains of the vanadium carbide coating may be coarsened, and the product quality may not be ensured by the adhesion of the coating.

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