| 摘要 |
<p>A galvannealed sheet steel which has an oxide layer having a thickness of 10 nm or more formed on convex portions of the surface of its plating layer having been flatted by temper rolling. The galvannealed sheet steel is free from the occurrence of powdering during press forming and also exhibits a slidability being excellent with stability. The restriction of the area percentage of the convex portions of the surface of the plating layer having been flatted to 20 to 80 % and the preparation of a plating layer having δ 1 phase alone or having δ 1 phase mainly and, incorporated therein, z phase lead to imparting more excellent slidability and resistance to poedering to the sheet steel.</p> |
