Stress Corrosion Cracking Behavior of Materials
Alireza Khalifeh
Abstract
Stress corrosion cracking is a phenomenon associated with a combination of tensile stress, corrosive environment and, in some cases, a metallurgical condition that causes the component to premature failures. The fractures are often sudden and catastrophic, which may occur after a short period of design life and a stress level much lower than the yield stress. It can also occur after several years of satisfactory services due to operating errors and changing process conditions. Two classic cases of stress corrosion cracking are seasonal cracking of brass in ammoniacal environment and sensitization and stress corrosion cracking of stainless steels in existence of chlorides, caustic, and polythionic acid. Presence of crack and other defects on the material surfaces accelerates the fracture processes. Therefore, when designing components, the role of imperfections and aggressive agents together must be taken into account. The fracture mechanic introduces a material characteristic namely fracture toughness or K ISCC = σ πa = σ π a , which properly describes the fracture behavior of materials in such conditions. The main objective in writing of this chapter is to present scientific findings and relevant engineering practice involving this phenomenon.