STEEL FOR STRUCTURAL PURPOSE EXCELLENT IN FATIGUE PROPERTY OF WELDED JOINT

摘要

PURPOSE: To stably produce steel for structural purpose in which high temp. strenth is reduced and welding residual stress is reduced and improved in the fatigue strength of a joint by specifying the compsn. constituted of C, Si, Mn, P, S, Ni, Cu, Al, B and iron. ;CONSTITUTION: This steel for structural purpose excellent in the fatigue properties of a welded joint is the one having a compsn. contg., by weight, 0.001 to 0.01% C, 0.005 to 0.05% Si, 0.05 to 1.00% Mn, ≤0.020% P, ≤0.010% S, 0.3 to 2.0% Ni, 0.5 to 2.0% Cu, 0.010 to 0.050% Al and 0.0001 to 0.0010% B, furthermore satisfying Ni/Cu ≥0.4, and the balance iron with other inevitable impurities, and in which the parameter A prescribed by the formula: A=0.350+22.8 C+12.5Si+16.8Mn+23.4P-164S+30.9Ni-2.24Cu-332Al is regulated to ≤15.;COPYRIGHT: (C)1995,JPO