Modeling the microstructure-mechanical property relationship for a 12Cr-2W-V-Mo-Ni power plant steel

For a 12Cr-2W-V-Mo-Ni power plant steel, the microstructure was characterized and the 0.2% proof strength was quantitatively related to its microstructure and chemical composition. The microstructural features including martensite lath width, carbide size and dislocation density were measured from transmission electron microscopy and the equilibrium concentrations of alloying elements dissolved in the matrix after tempering were calculated using the 'Metallurgical Thermodynamic Data Bank' (MTDATA). The strengthening contribution to the 0.2% proof stress was evaluated from each individual strengthening mechanism by using measured microstructural parameters. The modeled 0.2% proof stress is compared with the experimental result and a reasonable agreement is reached by root mean-square summation, while the simple linear summation gives an overestimated result. The accuracy and limitation of the present modeling is also discussed