Stress corrosion cracking (SCC) is the growth of a crack in a corrosive environment. It requires three conditions to take place: 1)corrosive environment 2)stress 3)susceptible material. SCC can lead to unexpected sudden and hence catastrophic failure of normally ductile metals under tensile stress. This is usually exacerbated at elevated temperature. SCC is highly chemically specific in that certain alloys are likely to undergo SCC only when exposed to a small number of chemical environments. It is common for SCC to go undetected prior to failure. SCC usually quite progresses rapidly after initial crack initiation, and is seen more often in alloys as opposed to pure metals. The corrosion engineer thus must be aware of this phenomenon.