Correspondence between hydrogen enhancing dezincification layer-induced stress and susceptibility to SCC of brass

Dezincification layer formed during corrosion or stress corrosion cracking (SCC) of brass in the ammonia solution could induce an additive stress. The effect of hydrogen on the dezincification layer-induced stress and the susceptibility to SCC were studied. The dezincification layer-induced stress was measured using the deflection method and the flow stress differential method. The susceptibility to SCC was measured using a slow strain rate test. Results showed that both the dezincification layer-induced stress and the susceptibility to SCC increased with increasing hydrogen concentration, and the hydrogen concentration dependence of the susceptibility to SCC was in a good agreement with that of the dezincification layer-induced stress. Hydrogen in brass facilitates the selective dissolution of Zn in the ammonia solution, and then enhances the dezincification layer-induced stress.