Stress Corrosion Cracking of Sensitized Type 304 Stainless Steel in Sulfate and Chloride Solutions at 250 C and 100 C

Abstract Slow strain rate tests have been used to study the stress corrosion susceptibility of sensitized Type 304 stainless steel in 0.01M Na2SO4 and 0.01M NaCl as a function of applied potential at 250 and 100 C. At 250 C, intergranular cracking occurs in both solutions at potentials greater than a critical potential, ∼ −0.3 VH, which is independent of the anion, but decreases with increasing degree of sensitization. At potentials higher than 0.0 VH, simultaneous transgranular and intergranular crack initiation occurs in chloride solution. The potential at which transgranular cracking appears on sensitized material coincides with the potential at which quenchannealed material is susceptible to transgranular cracking. At 100 C, intergranular cracking initiated on pits occurs only in chloride solution at potentials greater than the pitting potential.