PRODUCTION OF MULTIPLE ZINC-CONTAINING COATINGS

摘要

Markedly superior corrosion protective properties are imparted to metal-bearing surfaces at substantially reduced costs by depositing upon said surfaces one or more superimposed zinc containing layers located intermediate the metal bearing surfaces and a sacrificial layer of generally pure zinc. The initial layer which is in direct contact with the metal bearing surface includes therein from about 3 to about 15% of an alloying element selected from the group consisting of nickel, iron or cobalt and a second layer deposited upon the initial layer having a relatively lower content of the alloying element as compared with the initial layer. In this manner penetration of rust inducing substances into the metal bearing surfaces is effectively precluded under substantially all environmental conditions normally encountered.