Evaluation Of Susceptibility Of 316L To Stress Corrosion Cracking In Aqueous Ammonium Chloride Environments With Low Dissolved Oxygen

Corrosion of stainless steel in applied industrial environments continues to be an area of concern for various refining operators. It is well accepted that a certain concentration of dissolved oxygen is required for chloride stress corrosion cracking (SCC). However, there are some environments where it is suspected that chloride SCC can occur even in the absence of dissolved oxygen. The susceptibility to SCC of 316L stainless steel has been studied in the pursuit of extending operating boundaries at higher temperatures under low dissolved oxygen concentrations. Slow strain rate tensile (SSRT) tests have been carried out for various temperatures and ammonium chloride concentrations under low dissolved oxygen conditions. The susceptibility to SCC was assessed in terms of the relative reduction in area (RRA). Detailed fractography and cross section inspections were used to identify the damage mechanisms. The implications of this behavior and its influence on improving material selection have been discussed.