An extended tensile flow curve model for carburized steels

An extended tensile flow curve model is derived for quenched-tempered as-carburized steels. It comprises a theoretical formula for calculating the yield strength of tempered martensite and a dislocation based strengthening theory. Precipitates transition in different tempering durations were taken into account, and an impact factor m was implemented to adjust the effect of confined precipitates in martensite matrix. The effective grain size dα′ evolution on tensile deformation behavior was taken into account to modify the tensile flow curve calculation as well. Favorable agreement was obtained between experimental and theoretical results. By means of this manner, it is feasible to evaluate the effect of microstructure evolution on strength and calculate the tensile flow curve, in terms of composition with defined treatment process.