Stress corrosion cracking (SCC) can lead to rapid and catastrophic failure in many different
metals and alloys. This phenomenon occurs under conditions where a component is exposed to a
mildly corrosive substance while under applied and/or residual tensile stress. Since this type of
cracking does not generally result in significant surface appearance changes or elongation, failures
often occur with little or no prior warning. A systematic approach is needed in order to evaluate any
failure and identify its physical cause, and the proper use of such an approach will greatly increase
the likelihood of successful failure mode identification and appropriate corrective action counsel.
SCC results in the development of certain characteristic features that can be recognized by an
experienced analyst during the course of a comprehensive failure investigation. The case histories
within this article illustrate features that are commonly evident in various materials that experience
SCC.