Evaluation of Microstructure and Ductile-Brittle Transition Temperature in Thermally aged 2.25Cr-1Mo Steel by Electrical Resistivity Measurement

An attempt was made to evaluate the degree of aging degradation in thermally aged 2.25Cr-1Mo steel by electrical resistivity measurement. Artificial aging was performed to simulate the microstructural degradation in 2.25Cr-1Mo steel arising from long time exposure at . Microstructural parameter (amount of solid solution element), mechanical property (ductile-brittle transition temperature) and electrical resistivity were measured to investigate the mutual relationship among these parameters. Depletion of solid solution element(Mo and Cr) in matrix was detected after aging. The ductile-brittle transition temperature(DBTT) increased rapidly in the initial stage of aging and then saturated afterward. On the other hand, the electrical resistivity decreased rapidly in the beginning and then saturated in the later stage of aging.