Stress corrosion cracking (SCC) of chloride exposed stainless steels under evaporative conditions has for long been recognized as a factor that needed special attention. In this investigation the SCC resistance of welded and rolled UNS S31803, UNS S32760 and UNS S31254 has been studied. The intention of the project was to generate some data on temperature limits for stress corrosion cracking in aggressive chloride environment. The assessment of SCC resistance has been done using a modified Drop Evaporation Test. The Drop Evaporation Test was performed at constant load using C - ring specimens. The specimens were loaded to yield point at ambient temperature and heated by electrical resistance heating. Synthetic seawater was used as electrolyte. No surface treatment prior to exposure was performed neither for the unwelded nor the welded specimens. The time to failure and the temperature at which cracking occurred were determined. The experimental data have been compared with literature data and practical experience from the use of these materials in aggressive chloride environment. All the three materials tested were found to suffer chloride stress corrosion cracking (CSCC) under severe evaporative conditions. The ranking of the materials tested was found to be UNS S31254> UNS S32760 > UNS S31803, i.e. UNS S31803 having the highest susceptibility to chloride stress corrosion cracking.
Keywords: Test method, chloride stress corrosion cracking, highly alloyed stainless steels, concentrated sea water, evaporative conditions, safe temperature limits.