The copper covering put in fused salts of chlorides at temperature of 450-500cC and preventing scuffs on the surface of steel of type 12X18H10T at cold stamping of case products and fixture was investigated. Metallurgical surveys have shown: 1) except cover zone and zone of base metal there is also transition zone, representing substitution type of solution; 2) in the course of application there is superficial alloying, due to penetration of atoms of copper deep into metal and diffusions of doping steel elements in coating material under the influence of melts's high temperature. The schedule of change of concentration of copper in diffusion zone allows to conclude that the copper covering consists not of pure copper, and that the alloy contains only 94% of copper; other 6% represent the chrome and the titanium diffusing in copper covering. It is established also that, despite strong cohesion with basis, the covering is completely removed from surface of the stamping details being dissolved in standard sulphuric acid solution.
Studies on the Corrosion of Stainless Steels in Organic Acid Solution (5)
