| 摘要 |
A hot dip zinc plated steel sheet having high strength, which has substantially a chemical composition in mass %: C: 0.03 to 0.25 %, Si: 0.7 % or less, Mn: 1.4 to 3.5 % or less, P: 0.05 % or less, S: 0.01 % or less, Cr: 0.05 to 1 %, Nb: 0.005 to 0.1 % and balance: Fe, and comprises a composite structure being composed of ferrite and a second phase and having an average grain diameter of 10 .mu.m or less. The hot dip zinc plated steel sheet havi ng high strength is advantageous in that, when it is welded, HAZ of the steel sheet is less susceptible to softening, and thus it can be suitably used for a structural member of an automobile utilizing a tailored blank (TWB) material . |
