Influence of thermal aging on SCC susceptibility of DSS 2304 in the presence of chlorides and thiosulphates

In this paper, the effect of brief aging within the 650–850 °C temperature range on the resistance of DSS 2304 to stress corrosion cracking (SCC) was discussed. Slow strain rate tests (SSRT) were performed on both as-received and heat treated DSS 2304 in the standard NACE TM-0177 solution at pH 2.7 and 25 °C in the presence of 10-3 M S2O32-. High SCC susceptibility was detected with aging at 650 °C for 60 min, at 750 °C for 10 and 60 min and at 850 °C for 10 min, in good agreement with preceding results obtained for pitting resistance and degree of sensitization to intergranular corrosion. The SCC susceptibility is likely connected to chromium concentration levels in the depleted zones, which depend on the adopted aging times and temperatures.