Honda Giken Kogyo Kabushiki Kaisha

Tsuyoshi Kokusho

Hideaki Ikeda

Masami Watanabe

Masanobu Ishikawa

Hideo Nakamura

Keizou Tanaka

Shigeru Ohno

The composition of a hard-facing welding material to be overlaid onto a cast iron base metal followed by a supercooling treatment for hardening must lie above a line LA in a Schaeffler's structure diagram which is represented by a Cr equivalent and a Ni equivalent. On the other hand, if the base metal is preheated, the carbon precipitation line will be at the Ni equivalent of 34 (LC1), and the Cr equivalent will thus be above 4. However, if the Cr equivalent is above 4, there will occur cracks after welding (examples in which cracks occurred are shown by square marks represented by a in FIG. 1). As a solution, the carbon precipitation line was raised up to the Ni equivalent of 38 without preheating the base metal, and the Cr equivalent of the welding material was made to be 4 or less.

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Saitama-ken, Japan

Tsuyoshi Kokusho