HIGH STRENGTH LOW ALLOY STEEL WITH SUPERIOR PLATING CRACK RESISTANCE AT WELD HEAT-AFFECTED ZONE

摘要

PURPOSE:To enhance the plating crack resistance of a high strength low alloy steel at the weld heat-affected zone by restricting the amounts of C, Mn, Si, Nb, Ti, V and Al contained in the steel to specified ranges. CONSTITUTION:The components of a low alloy steel having =55kg/mm.2 strength are restricted to 0.04-0.11% C, 0.90-1.70% Mn, 0.05-0.30% Si, 0.01-0.08% Nb, 0.02-0.09% V, 0.005-0.030% Ti and 0.005-0.050% Al while satisfying quantitative relation represented by 93-8.8X103C(C-0.1)-63Si-38M+430V=42. The occurrence of intercrystalline cracks in the resulting steel at the weld heat- affected zone is prevented when the steel is subjected to galvanizing or other plating.