研究論文
球状黒鉛鋳鉄のレーザ硬化におけるミク口組織の影響
1998 年 70 巻 1 号 p. 33-39
詳細
1998 年 70 巻 1 号 p. 33-39
Influence of microstructure on the effect of laser beam surface hardening of spheroidal gphite cast iron was investigated. Cast irons with a bull’s eye structure and ferritic matrix were used to clarify the effect of matrix microstructure by laser treatment. At the same time, cast irons with different graphite nodule sizes were laser treated for the investigation of the effect of graphite size on melting behavior. Spheroidal graphite cast irons were coated by graphite powder and/or tungsten powder for YAG laser carburizing and/or tungsten alloying. Microscopic observations were carried out on the laser-treated surface layers. The surface layer of the cast irons formed into a chill structure by rapid melting and cooling with laser beam scanning. The melted depth of cast irons were varied with the microstructure and coatings. For example, the melted depth of ferritic matrix irons was deeper than that of bull’s eye cast irons. Moreover, the carbide fraction of chilled layers was varied with graphite nodule size.
