| 摘要 |
PROBLEM TO BE SOLVED: To provide a galvannealed steel sheet which has excellent surface appearance and press formability, and a production technique therefor. SOLUTION: At least either side of a steel sheet having a composition containing, by mass, 0.001 to 0.005% C, 0.010 to 0.040% Si, 0.05 to 0.25% Mn and 0.010 to 0.030% P, and in which the above Si, Mn and P are contained also so as to satisfy 0.030%<=Si+P+Mn/20<=0.070% is galvanized, and alloying treatment is performed thereto in the temperature range of 500 to 520 deg.C. |
