Activation of Superalloys and Stainless Steels for Chromium Plating

摘要

the adhesion of electrodeposited chromium on cobalt, nickel and iron-nickel based superalloys such as CG-27, Haynes alloy 25, and Udimet 700, as well as stainless steels was investigated. A number of pretreatments were used to activate these alloys. The results show that a hydrofluoric-sulfuric acid pretreatment used anodically produces excellent adhesion. A qualitative adhesion test, named the 'Groove Test' was developed to evaluate the adhesion of thick deposits of chromium on metallic substrates. The development of this test is described. (Author)