HIGH MANGANESE ULTRAHIGH TENSILE STRENGTH STEEL EXCELLENT IN TOUGHNESS IN WELD HEAT AFFECTED ZONE

摘要

PURPOSE:To manufacture a high manganese ultrahigh tensile strength steel excellent in toughness in a weld heat affected zone by preparing a steel having a specified compsn. in which each content of C, Mn and B is specified. CONSTITUTION:A steel contg., by weight, 0.01 to 0.06% C, 0.01 to 1.0% Si, 6 to 15% Mn, =0.01% P, =0.01% S, 0.005 to 0.1% Al, 0.0003 to 0.010% B and =0.010% N, furthermore contg., as necessary, one or two kinds of =3.0% Ni and =1.5% Cu and the balance Fe with inevitable impurities is prepd. In such a manner, a high manganese ultrahigh tensile strength steel having about =100kgf/mm2 tensile strength and furthermore excellent in toughness in a weld affected zone having good low temp. toughness even in welding by heat input in a wide area from middle heat input with about 40 to 200kJ/cm welding heat input to high heat input welding can be obtd.