Q: What are Stress Corrosion Cracking and Corrosion Fatigue? A: STRESS CORROSION CRACKING: Tensile stresses act in concert with corrosion. Stresses can be external or residual. Can result in catastrophic failure. Intergranular or transgranular caracking can occur. Intergranular corrosion tendencies are good initiation points. Austenitic SS and precipitation hardening Al alloys are prime candidates. CORROSION FATIGUE: Fluctuating or cyclic stress imposed on corrosive environment produces fine to broad cracks with little or no branching. Typically filled with corrosion product. Stress concentrations are frequently present (pits, grooves). Transgranular is more common. In less aggressive environments, "shot peening" helps to increase fatigue life.