| 摘要 |
PURPOSE:To inexpensively produce a high strength zinc hot dipped steel of excellent workability by subjecting a cold rolled steel plate of a steel contg. specific ratios of C, Si, Mn, P, S, solAl to zinc hot dipping under specific conditions. CONSTITUTION:Steel consisting of 0.01-0.15% C, <=0.08% Si, 0.10-1.2% Mn, 0.05-0.15% P, <=0.025% S, 0.01-0.10% solAl, and the balance iron and unavoidable impurities is hot rolled and cold rolled, whereby a cold rolled strip is produced. The resultant cold rolled strip is passed through a Sendzimir type zinc hot dipping device. At this time, it is heated for 5-120sec at Ac1-850 deg.C. Thence, the zinc plated layer is subjected to alloying treatment at 500-600 deg.C to have improve resistance weldability. Further, it is over aged at 200-400 deg.C to have improved elongation. |
