STEEL SHEET WITH TIGHT SCALE AND ITS MANUFACTURE

摘要

PROBLEM TO BE SOLVED: To provide a steel sheet with tight scale on which the scale having structure more excellent than conventional scale in adhesion is generated and manufacturing method thereof. SOLUTION: This sheet is the steel sheet which has a ground iron and the scale layer of <=15μm thick which is formed on the surface of the ground iron. The scale layer has structure in which magnetite which is generated from the outer layer is suppressed as much as possible and a magnetite phase is generated from the boundary between the scale and the ground iron and, moreover, eutectoid transformation structure consisting of the magnetite and iron is generated from the intermediate layer of the scale so as to be >=6% by volume and the balance consists of wustite essentially.