Experimental Procedures and Diagnostics of Sensitization by DL-EPR

Introduction There is great industrial interest in developing non-destructive tests for the detection of deleterious phases in stainless steels. In this context, the Electrochemical Potentiodynamic Reactivation [EPR] technique, described by the standard ISO 12732, can be used as a tool for quantitative analysis of the degree of sensitization [DOS] of austenitic stainless steels [1] . The influence of the experimental parameters on the results is an important limitation for practical use of the technique [2, 3, 4] . This study performs a critical analysis of the standard usefulness, mainly evaluating the influence of potential scan rate and concentration of potassium thiocyanate [KSCN] in the test solution. Actually, the EPR method can be sensitive to the DOS of the studied material. However, the classification given by ISO 12732 can lead to errors whether standard curves previously established for the steel are not considered.