Grain-Boundary Chemistry Effects on the Intergranular Stress Corrosion of Iron Alloys in Sulfate and Nitrate Solutions

摘要: Abstract Intergranular stress corrosion measurements have been made on Fe alloys in 1 M sodium sulfate at electrochemical potentials of +750 to +1250 +1250 mVSCE and 55% calcium nitrate 6CPC +750 mVSCE. Tests were conducted with variable grain-boundary S P concentrations ranging from 0.04 0.23 monolayers 0 0.31 P. Compact tension samples used measure the subcritical crack growth behavior. The solutions considerably more effective causing than was solution. Crack thresholds, KISCC, 6 MPam 3 MPam observed for P, respectively, when tested 13 MPam sulfate. A clear correlation between total S+P concentration KISCC velocity. rates about a factor 10 faster In general, grow...