Production manner null of the melting Zn plated steel sheet and the alloy melting Zn plated steel sheet due to pre- Ni alloy plated

摘要

PURPOSE: To provide a method for manufacturing a hog dip galvanized steel sheet and a galvannealed steel sheet by a pre-Ni alloy plating method for improving the galvanizing properties of a steel sheet for building materials, house appliances and automobiles and also the plating adhesion of galvannealing, to suppress the elution of pre-plating at the time of galvanizing. ;CONSTITUTION: This steel sheet is a hot dip galvanized steel sheet having features that the surface of a steel sheet is plated with an Ni alloy contg. ≥0.1% of one or ≥two kinds of P, S, B, Mo, Zn, Fe, Co, Cu, Cr, Sn and W by 0.2 to 2g/m², and after that, it is heated to 420 to 500°C sheet temp. in a nonoxidizing atmosphere, is immersed into a galvanizing both contg. 0.05 to 1% Al for ≤15sec at ≥350°C or at ≥30°C/s temp. rising rate in a stage till the steel sheet is impregnated into the bath and is galvanized. Furthermore, right after wiping subsequent to the galvanizing, this steel sheet is subjected to alloying treatment in the temp. range of 470 to 550°C for 5 to 40sec.;COPYRIGHT: (C)1993,JPO&Japio