HIGH CARBON HIGH MANGANESE STEEL WITH HIGH MACHINABILITY

摘要

PURPOSE:To enhance the machinability of a high carbon high manganese steel of a predetermined compsn. by specifying the amt. of oxides entering the anorthite region in the ternary phase diagram of nonmetallic inclusion CaO-Al2O3-SiO2 of the steel. CONSTITUTION:In a high Mn steel consisting of C=2.0%, Si=2.0%, Mn 7-40% and the balance Fe essentially, the compsn. of nonmetallic inclusions (oxides) is set in the anorthite region in the CaO-Al2O3-SiO2 ternary phase diagram. This ternary oxide amt. is adjusted to 80% of the total oxide amt., and 0.0005-0.02% Ca is added optionally together with Pb, S and Se. By this restricted compsn. a high carbon high manganese steel is obtd. which is suitable for use as a high strength nonmagnetic material or a wear and impact resistant material requiring machinability.