MANUFACTURE OF HOT-DIP ZN-AL PLATED STEEL SHEET EXCELLENT IN APPEARANCE, SECULAR BLACKENING RESISTANCE AND CORROSION RESISTANCE

摘要

PURPOSE: To provide a hot-dip Zn-Al plated steer sheet excellent in appearance, secular blackening resistance and workability and its manufacturing method. ;CONSTITUTION: In a continuous galvanizing line, the steel sheet to be plated is plated by using a plating bath of 410 to 470°C having a compsn. constituted of, by weight, 3 to 10% Al, 0.01 to 1% Ti and the balance Zn. After that, at the time of cooling the above steel sheet, its cooling rate is regulated to 15 to 100°C/sec in a process in which the sheet temp. reduces from 400 to 380°C, by which the hot-dip Zn-Al plated steel sheet excellent in appearance, secular blackening resistance and workability can be manufactured.;COPYRIGHT: (C)1993,JPO&Japio