Comparison in the Stress Corrosion Cracking Susceptibility of Austenitic Stainless Steels in the Japanese Industrial Standard

Stress corrosion cracking of the types SUS 27,28,32 and 33 austenitic stainless steels in the Japanese Industrial Standard exposed to 42% MgCl_2 aqueous solution was investigated. The relationships between time-to-failure and applied stress at a temperature of 154℃ (boiling), 140℃ and 125℃ respectively were tested and obtained results are as follows. 1. The resistance to stress corrosion cracking increased in the order SUS 27,28,32 and 33 type steels, namely the type SUS 33 was most resistant, but the difference of types SUS 33 and 32 was very minor and also that of the types SUS 28 and 27 was minor, furthermore this difference was not noticed at 140℃ and 125℃. 2. The time to failure by stress corrosion is increased by a decrease in temperature. 3. The resistance of quenched steels was superior to that of rolled steels, especially it was markedly at lower applied stress. 4. Stress corrosion failures can occur also in austenitic steel with only residual stress as rolled. 5. In our experiments transgranular cracks were observed at all and intergranular crack was not observed.