Stress Corrosion Cracking of Sensitized AISI 304 Stainless Steel in High-Temperature Sodium Sulfate Solutions

The susceptibility of sensitized AISI 304 stainless steel (SS) to intergranular stress corrosion cracking (IGSCC) was studied in 0.01 M Na₂SO₄ solution at temperatures ranging from 100 to 250 C under constant load conditions. The susceptibility increased in the middle of the passive potential at 150 and 175 C and in the transpassive potential at 200 and 250 C. IGSCC nucleated from the crevice corrosion (CC) around a pinhole of a flat tensile specimen occurred over a wide range of potentials at 100 C and in the transpassive potential range at temperatures ranging from 125 to 175 C. IGSCC was significantly accelerated by an artificial crevice. The susceptibility was discussed from the nature of (1) the passive film and (2) environmental solution.