Environmental Influence on SCC

Stress corrosion cracking is dependent on the environment based on a number of factors including temperature, solution, metallic structure and composition, and stress.12 However, not all environments are equally potent to all metals; that is, specific metals are susceptible to specific chemical species, and some alloys are susceptible to SCC in one environment while others are more resistant.

Increasing the temperature of a system often works to accelerate the rate of SCC. The presence of chlorides or oxygen in the environment can also significantly influence the occurrence and rate of SCC. SCC is a concern in alloys that produce a surface film in certain environments, since the film may protect the alloy from other forms of corrosion, but not SCC. Some specific environments that can cause SCC of certain metals are listed in Table 15.