Effect of non-equilibrium grain-boundary segregation of phosphorus on the intermediate-temperature ductility minimum of an Fe–17Cr alloy

The ductility of an Fe–17Cr alloy was examined experimentally in the range of 350–700 °C. The results showed that the ductility of the alloy, evaluated by the reduction in area, had a minimum at an intermediate temperature of approximately 450 °C. Auger electron spectroscopy demonstrated that the ductility minimum corresponded to a maximum in grain boundary segregation of phosphorus, which could be elucidated by the theory of non-equilibrium grain-boundary segregation. Thus, the intermediate temperature ductility minimum for the Fe–17Cr alloy could be explained on the basis of non-equilibrium grain-boundary segregation of phosphorus.