白鋳鉄の黒鉛化に及ぼす窒化アルミニウムとアルミニウムの影響

抄録

  The influence of Al and AlN content upon the graphitization of white cast iron was investigated by repitition of heating and cooling. In white cast iron with low Si content, graphitization of about 0.55%Al specimen starts at about 1,000°C, and graphites precipitated are like snowflakes or starflakes. When Al content is over 1%, graphitization starts at about 650°C, and graphites precipitated are fine and granular. Aluminum nitride is also produced at the solid state and it reduces the solutionizied nitrogen which has the tendency of accelerating cementite crystallization. Graphitization of white cast iron and mottled cast iron containing Si starts at about 650°C, and graphites precipitated become finer. As Al content increase, the Ac₁ transformation temperature rises.