High Temperature Deformation Behavior of P92 Steel

The ferritic-martensitic steels are superior steels based on the potential properties that they possess; especially, the elevated temperature properties. Among these ferritic-martensitic steels, Cr-Mo-W steel is a candidate structural material for high temperature applications such as future advanced reactors and aerospace applications. The hot deformation behavior of P92 steel was carried out at elevated temperatures between 600 and 700 A degrees C and different strain rates of 10(-5)-10(-3) s(-1). Thereafter, the hot deformation behavior was analyzed, taking into account the peak stress values for each condition. As a result, the activation energy of P92 steel and the stress exponent were obtained to be 6.7 and 628 kJ/mol, respectively. The activation energy assessed the high-temperature deformation mechanism for this class of steels. Even though, the obtained activation energy was much higher than that of iron self-diffusion, it came in good agreement with the reported values in literature. Subsequently, the relevant hot deformation constitutive equation and the relationship between peak stresses and deformation rate at elevated temperature were developed.