Author: RN. Parkins

Publisher:

Published: 1988

Total Pages: 10

ISBN-13:

The stress corrosion cracking of alloys is markedly sensitive to the environment to which they are exposed, so that an alloy developed to have low susceptibility to such failure in a particular environment will not necessarily show such behavior in a different environment, as illustrated by a number of examples. It is also possible for results from tests using standard environments to lead to the exclusion of the use of materials that may behave satisfactorily in service. While it is obvious that tests should be conducted, whenever possible, in environments relevant to particular service conditions, these are not necessarily known when alloy development programs are being undertaken in the laboratory, hence the need for standardized or synthetic solutions. Evidence for the cracking domains for ferritic steels and ?-brasses suggests that stress corrosion cracking in a range of environments occurs at potentials and pH's where the lower oxide of the relevant metal can form. This suggests that laboratory tests should involve more than a single standardized environment, and that variation from test to test of potential and pH, guided by the potential pH diagram, may provide a more reliable guide to stress corrosion cracking propensities than that obtained from tests in a single solution.