| 摘要 |
[Problem] To provide a high-strength plated steel plate that is excellent in the corrosion resistance of the welded portion, the resistance to liquid metal embrittlement cracking, and the bending workability. [Solution to Problem] 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 µm 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. |
