| 摘要 |
<p>A process for producing an alloyed hot-dip zinc-coated steel sheet which has better processability than steel sheets produced by the Sendzimir process and non-oxidizing furnace process and is satisfactory also in non-powdering properties and sliding properties. The process is characterized by: subjecting a steel billet which contains, in terms of mass%, 0.01-0.12% C, 0.05-0.6% Mn, 0.002-0.1% Si, up to 0.05% P, up to 0.03% S, 0.005-0.1% sol.Al, and up to 0.01% N, the remainder being Fe and unavoidable impurities, to hot rolling, pickling, and cold rolling; subsequently annealing the work at 650-900°C; cooling it to 250-450°C and holding it for 120 seconds or longer; thereafter cooling the work to room temperature; pickling the cooled work; preplating it with nickel or nickel-iron without conducting temper rolling; heating it to 430-500°C at a rate of 5 °C/sec or higher; plating the heated work with zinc in a plating bath; wiping the plated work; heating it to 460-550°C at a heating rate of 20 °C/sec or higher; cooling it at a rate of 3 °C/sec or higher either without soaking or after soaking for less than 5 seconds; and then conducting final temper rolling so as to result in an elongation of 0.4-2%.</p> |
