Study on the role of tarnishing film in stress-corrosion cracking of brass in Mattsson's solution

In this paper, the influence of tarnishing film-induced stress and tarnishing film-induced brittle cracking on stress-corrosion cracking (SCC) of brass in Mattsson’s solution are investigated using hydrogen charging. Results showed that the SCC susceptibility of brass in Mattsson’s solution increased with the increase of tarnishing film-induced tensile stress. Also, the film-induced brittle cracking showed little effect on SCC susceptibility. From the results obtained, an improved SCC mechanism is proposed to explain the role of the tarnishing film-induced stress and the film-induced brittle cracking in SCC of brass in Mattsson’s solution. It seems that the film-induced brittle cracking is responsible for crack initiation of ductile brass. Also, the SCC susceptibility of brass in Mattsson’s solution was controlled by the growth rate of tarnishing film. Hydrogen enhanced the SCC susceptibility, which can be ascribed to the fact that hydrogen facilitates the tarnishing film growth.