MANUFACTURE OF 18 NI TYPE MARAGING STEEL

摘要

PURPOSE:To provide superior toughness to 18% Ni type maraging steel by combining a proper pressure reduction schedule in a hot working stage with a proper temp. conditions during the subsequent heat melting treatment. CONSTITUTION:When 18% Ni type maraging steel contg. =0.0005wt% B is hot worked at 1,200-1,600 deg.C, working is carried out in a temp. range except the temp. range of 800-900 deg.C and one or more passes of the hot working are carried out by working at =20% rate of working per one pass and at 900 deg.C. The hot worked steel is subjected to heat melting treatment in the temp. range of 1,050-750 deg.C. At this time, the steel is subjected to heat melting treatment by heating to a temp. in a temp. range except the temp. range of 930-850 deg.C. The steel is then aged.