Influence of internal stresses on corrosion crack of single-phase brasses in ammonia atmosphere.

The effect of internal stresses on corrosion crack of single-phase brasses in ammonia atmosphere is presented. The pipes made of CuZn28Sn1 and CuZn20Al2 brasses were investigated. The stress simulating the remainders after the drawing process and mechanical damages in the form of indentation were introduced. It was found that the tin brass is more sensitive to corrosion cracking than the other. It was also stated that the amount of cracking on the degree of deformation dependence is different for each grade of brass. In the aluminium brass the cracks are shorter. The corrosion cracks lead of the brittle fracture.