Patent ID: 10100395

Abstract:
A high-strength plated steel plate for a welded structural member having a steel composition containing from 0.050 to 0.150% of C, from 0.001 to 1.00% of Si, from 1.00 to 2.50% of Mn, from 0.005 to 0.050% of P, from 0.001 to 0.020% of S, and from 0.005 to 0.100% of Al, having a steel base material having a metal structure containing a ferrite phase and a second phase containing mainly martensite having an average crystal grain diameter of 8 mm or less, and having a chemical composition and a thickness t (mm) of the steel base material regulated to obtain a value, C/0.2+Si/5.0+Mn/1.3+Cr/1.0+Mo/1.2+0.4t−0.7(Cr+Mo)1/2, of 2.9 or less. The high-strength plated steel plate is excellent in corrosion resistance of the welded portion, resistance to liquid metal embrittlement cracking, and bending workability.