| 摘要 |
PURPOSE:To produce an alloyed and galvanized steel sheet having good processability, by heat-treating a Ti-added steel sheet at a specific max. temp. then subjecting the same to zinc-hot-dipping followed by a heat treatment. CONSTITUTION:The max. temp. Tmax. for the heat treatment prior to zinc hot dippling is so determined as to satisfy the equation I (R; rolling reduction, CTi; the content of Ti in steel %) and the equation II, in the stage of zinc-hot-dipping a steel sheet contg. 0.05-0.15% Ti followed by a heat treatment thereby producing the plated steel plate. The reactivity of molten zinc in the Ti-added steel sheet of aluminum-killed ultralow carbon steel is decreased to the reactivity equivalent to ordinary steels and the alloyed and galvanized steel sheet having good processability is produced stably. |
