Effects of Sulphur, Oxygen and Silicon on Graphite Precipitation in Calcium Graphite Steel

概要

論文の詳細を見る
Effects of sulphur, oxygen and silicon on the graphite precipitation in calcium graphite steel were investigated. Sulphur greatly hindered the precipitation from γ solid solution. According as the amount from 0.03 to 0.18% of sulphur, primary cementite appeared not only in the matrix but also in the grain boundary. With increasing oxygen content above 0.008%, graphitization decreased and also primary cementite crystallized out preferentially from the γ solid solution. When the hypereutectoid steel was melted in vacuum, graphitization did not occur without a suitable addition of silicon. Fundamental conditions on graphite precipitation by the calcium treatment were summarized in the following three points : (1) effect of deoxidization and desulphurization, (2) instabilization of cementite to precipitate from the γ solid solution, and (3) formatian of crystal imperfections such as voids in the solidifying process. Effective acceleration of graphite precipitation due to silicon was also discussed.
東北大学の論文