ZN-CR BASE SURFACE-BACK DIFFERENT PLATING RUST PREVENTIVE STEEL SHEET EXCELLENT IN CORROSION RESISTANCE

摘要

PURPOSE: To obtain a rust preventive steel sheet having excellent corrosion resistance both in the outer side and inner side by forming Zn-Cr base plating layers with different Cr content on both sides of a steel sheet. ;CONSTITUTION: One side of a steel sheet is applied with Zn-Cr base plating contg., by weight, 0.1 to 6% Cr and in which, as for the existing state of Cr, 0 valence is not substantially contained is applied on one side of a steel sheet. The other side is applied with Zn-Cr base alloy plating contg. 6 to 30% Cr. The plating layer on one side may contain 0.1 to 5% Co and 0.01 to 5% alumina sol. At the time of using it in such a manner that the one contg. lower Cr content as the outer side and the one contg. higher Cr content as the inner side, excellent corrosion resistance can be obtd. in corrosive environments on both sides.;COPYRIGHT: (C)1994,JPO&Japio