Intergranular Corrosion in Alloy 800: Intercomparison between the Strauss Test, the EPR Method and Magnetic Permeability Measurements

The susceptibility to intergranular corrosion of different heats of Alloy 800 has been evaluated by three different methods: the ASTM A 262 Practice E (or modified Strauss test), the Electrochemical Potentiokinetic Reactivation method and by magnetic susceptibility measurements. Reasonably good agreement has beenfound between the sensitisation areas as defined by the three methods in the TTS diagrams. In some cases the area defined by the Strauss test was slightly smaller than that determined by the other two tests. The differences might be explained by the fact that the methods present different sensitivities to the chromium concentration at the grain boundaries.