Numerical investigation on the stress corrosion cracking of FV520B based on the cohesive zone model

Tensile failure process of plane specimens and unilateral V-notched specimens is simulated basing on cohesive zone model (CZM). The internal stress in corrosion scales and film-induced stress in matrix increases with the increase of corrosion scale thickness. The thicker the corrosion scales are, the smaller the crack initiation strength is and the easier to initiate and propagate for stress corrosion cracks are. Meanwhile, with the thickness of corrosion scale increasing, the stress corrosion cracking (SCC) sensitivity of plane specimen increases and K-ISCC of unilateral V-notch specimens are reduced, making the stress corrosion cracks more likely to propagate. Simulation results show that the stress corrosion cracks nucleate on the surface of corrosion scale and propagate gradually until corrosion scale broke with the continuous tensile load. Finally, stress corrosion cracks propagate into the matrix.