The Study On EPR Behavior Of 30Cr2MoV Rotor Steel

This paper investigated the EPR behaviors of 30Cr2MoV steel used for the turbine rotor. EPR test, short for electrochemical potentiodynamic reaction, aims to detect the sensitization of intergranular corrosion. The temper embrittlement of long-running turbine rotor steel mainly results from the phosphorus segregation in the grain boundary, and picric acid has a good selectivity to the phosphorus, produce the effect of intergranular attack, so the double loop EPR test was adopted to measure the reactive charge Qr in picric acid solution system. In the best test condition, the reactive charge Qr was got for the rotor steel with the different P% content and different aging degree. The data results indicate that the FATT50 (fracture appearance transition temperature) has a close linear relationship with Qr, chemical ingredient, mechanical performance, so FATT50 could be estimate from the math model. The result could be used as the bases in the management work of turbine, including overhaul, life-forecast and abandonment.