共晶合金における安定系/準安定系圧力誘起遷移
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概要
- 論文の詳細を見る
Fe-C-Si eutectic alloys were melted and solidified under various cooling rates and pressures up to 1000 MPa using a piston-cylinder type high pressure apparatus. Metastable eutectic was observed in the inner region of a specimen slowly cooled under a pressure of about 800 MPa. The observed transition from stable eutectic (Gray) to metastable eutectic (White) was explained by the pressure dependence of the stable and metastable eutectic temperatures. Solidification analysis involving the pressure dependence of eutectic temperatures agreed well with the observed chill fraction. The critical pressure for Gray to White transition was estimated to be around 200 MPa for commercial grade cast irons. From the stress analysis for cylindrical castings having different sizes, it was suggested that the maximum pressure generated during solidification depends upon the strength of the outer solidified shell and that the pressure-induced stable to metastable transition possibly occurs in spheroidal cast iron with a pearlitic matrix.
- 長崎大学の論文