METHOD OF METALLIZED SHEET-IRON STRIPS TREATMENT MADE OF LOW-CARBON WELDING STEELS

摘要

A method of treating coated sheet metal strips of low-carbon welding steel designed for the automobile industry or profile warping while hot with cold rolling, pyrogenic treatment of zinc or its alloys, inclusive of alloys of zinc with aluminium with additives, based on the fact that the rolls of coated sheet metal strips are diffusively annealed in bell furnaces at 200 to 535 degrees C and then they are lightly rolled with reduction of 0.4 to 1.5 %. With this method of processing the sheet metal strips are preferably rolled while cold to a coarseness of Re=0.04 to 1.0 micrometers and they are coated with zinc with rising coarseness of 40 to 80 g.m<-2> on one side, or 80 to 160 g.m<-2> on both sides. Diffusion annealing occurs during 2.5 to 3.5 hours operation at the selected temperature and with retardation for another 9.0 to 10.5 hours.