OBERFLÄCHENBEHANDELTES STAHLBLECH MIT WENIGER BESCHICHTUNGSFEHLERN UND DESSEN PRODUKTION

摘要

A method of inhibiting failures in plating at a low cost in a stabilized manner in the step of subjecting a steel sheet containing a highly oxidizable element such as Si, Mn, P, Ti, Nb, Al, Ni, Cu, Mo, V, Cr or B to hot-dip galvanizing and hot-dip alloy galvanizing in a continuous line after annealing or to electroplating after annealing; and a surface-treated steel sheet reduced in plating defects. A surface-treated steel sheet which is reduced in plating defects, has an iron plating layer just under a zinc plating layer or a zinc alloy plating layer and has a layer enriched with steel ingredients just under the iron plating layer, is produced by applying iron plating to at least one side of a steel sheet in such a manner that the coating weight is 0.1-10 g/cm<2> and the oxygen content of the plating layer is 0.1-10 wt.%, followed by annealing and then zinc or zinc alloy plating. It is preferable to use an electroplating bath containing 0.1-10 g/l of Fe<3><+> ions and a carboxylic acid or an alkali metal salt thereof in the iron plating.