Effect of Minor Elements on Intergranular Stress-Corrosion Cracking of Carbon Steel in Aqueous Amine Solution

Abstract

Effect of minor elements on the intergranular stress-corrosion cracking (IGSCC) of carbon steel in an aqueous amine solution has been studied using slow strain rate testing (SSRT) technique at potentials in an active-passive transition range. A series of carbon steels with varying content of minor elements such as C, N, P, S and Si was used as specimens. The SSRT was carried out at a strain rate of 1.11×10^-6/s in a 20mass%MEA solution of pH8 at 333K. It was found that the IGSCC of the carbon steels depended upon potentials and susceptibility maxima to the IGSCC were attained at potentials in the center of active-passive transition ranges. The susceptibility to the IGSCC increased with decreasing C and N content and with increasing P and Si content of the carbon steels. The susceptibility to the IGSCC hardly changed with increasing S content of the carbon steels.