STEEL PLATE, HOT-DIP STEEL PLATE AND ALLOYED HOT-DIP STEEL PLATE AND PRODUCTION METHODS THEREFOR

摘要

This invention can form a sufficiently internal oxide layer in a surface layer portion of an iron matrix of a steel sheet by hot rolling a base steel and subjecting to a heat treatment at a temperature range of 650-950°C in an atmosphere substantially not causing reduction while being adhered with a black skin scale irrespectively of a chemical steel composition or production history, or even when a radiation type beating of a radial tube or the like is used in a recrystallization annealing before a hot dipping treatment, and hence excellent hot-dipping property and conversion treating property can be given to a steel sheet for hot dipping.