High strength prim. graphite-free cast iron@ prodn.

摘要

Prodn. of a prim. graphite-free cast iron, with a high strength of above 400 MPa, involves (a) desulphurising and deoxidation the cast iron melt with magnesium; (b) adjusting the final contents of oxygen and sulphur to below 0.001% and below 0.002% respectively by addn. of further magnesium and titanium and/or manganese, the titanium being mainly in oxide form; and (c) casting the melt after the requisite reaction time. Also claimed is a cast iron workpiece with a high strength of above 400 MPa and consisting of exclusively non-cellular solidified, finely dispersed, undercooled graphite in a ferritic and/or pearlitic cast iron matrix.