Investigations using smooth and notched specimens into validity of caustic cracking susceptibility diagram

Susceptibility to caustic cracking at different temperatures and caustic concentrations, as predicated by the caustic cracking susceptibility diagram, has been examined by stress corrosion cracking tests using smooth specimens (by slow strain rate testing) and notched specimens (by cylindrical notch tensile testing). Intergranular fracture, as established by scanning electron microscopy, was taken as the confirmatory evidence of caustic cracking. The results generated using notched specimens largely have been consistent with the prediction of the susceptibility diagram.