Stress corrosion cracking behavior of 2205 duplex stainless steel in concentrated NaCl solution

The stress corrosion cracking (SCC) behavior of 2205 duplex stainless steel (DSS) in 26 wt% NaCl solution at 90 degrees C was investigated. Slow strain rate testing was performed at a strain rate of 4.1 x 10(-6) s(-1). The susceptibility of 2205 DSS to SCC at open circuit potential and at various anodic potentials was evaluated. The experimental results showed that 2205 DSS was immune to SCC in the solution at potentials less than -160 mV (SCE). At potentials: greater than -160 mV (SCE), a dramatic reduction in ductility was observed, indicating the susceptibility to SCC. The critical potential for the occurrence of SCC of 2205 DSS was coincident with its pitting potential in the above environment. Fractographical examination revealed that pitting corrosion assisted the initiation and selective dissolution was involved in the propagation of SCC of 2205 DSS in concentrated NaCl solution at 90 degrees C. (C) 2000 Elsevier Science Ltd. All rights reserved.