NG-18-28-R02 Threshold Stress for SCC Through Overstain During Pipe-Forming Operation

Previous research showed that the threshold stress for stress corrosion cracking (SCC) of X52 steel under steady loading could be controlled at a high level (near the yield strength) if the steel were strained between 4 and 7 percent and then aged at 300F for about 1 hour. In an attempt to evaluate the feasibility of using such straining as a practical approach to preventing sec, an experimental program was conducted to evaluate the effect of such straining and aging on the threshold stress of a variety of grades of line-pipe steels subjected to the more realistic condition of cyclic stress superimposed on steady mean stress.