Environmentally assisted cracking behavior of duplex stainless steel in concentrated sodium chloride solution

The effect of applied potential on the environmentally assisted cracking in 2205 duplex stainless steels (DSSs) in 26 wt% NaCl of pH 2 was investigated. Slow strain rate testing (SSRT) technique was employed. The results showed that the reduction in ultimate tensile strength (UTS), the uniform elongation (UEL) and the reduction of area (RA) varied with the applied potential. A complicated function of potential for the environmentally assisted cracking was found. Stress corrosion cracking occurred in a narrow potential range (-380 to -500 mV) near to corrosion potential. Hydrogen assisted cracking, on the other hand, participated in the fracture process of 2205 DSS under cathodic polarization in this acidic concentrated chloride solution. Fractographical examinations showed that ferrite phase, as compared with the austenite phase, was less resistant to environmentally assisted cracking. (C) 2000 Elsevier Science Ltd. All rights reserved.