Corrosion Cracking of Steels of Various Strengths at a Constant Crack Opening

Resumo

Earlier, we proposed a technique to estimate the fracture toughness of a metallic material. It differs from standard techniques in the determination of the operating stresses in an improved compact specimen with an edge crack. Using this technique, we determine the corrosion damage resistance of martensitic 30KhGSA (σ_u ≈ 1080 MPa) and VKS-9n (σ_u ≈ 2010 MPa) steels under full-scale and laboratory conditions and analyze their corrosion fracture kinetics. The corrosion fractures of the steels with different strength levels are found to have different characters: the 30KhGSA steel is likely to undergo anodic dissolution at the crack tip, and the high-strength VKS-9 steel undergoes hydrogen embrittlement.