Excellent tin-plated system or aluminum plating-based surface treatment steel to corrosion resistance

摘要

Tin plated or aluminum plated surface treated steel containing an intermetallic compound composed of one or more IIA (alkaline earth metal) elements and one or more IVB group elements in a tin based plating layer or an aluminum plating layer on the steel surface. In the case of the tin based plating layer, the large diameter of the intermetallic compound of the bulk is 1. Mu. M or more, and the ratio to the long diameter of the short diameter is 0.4 or more. In the case of the aluminum based plating layer, the ratio of the long intermetallic compound to the length of 10. Mu. M or more and the ratio to the long diameter of the short diameter is 0.4 or more.