Effect of multiple dispersion of hard VC and soft cu particles on mechanical properties in ferritic steel

The tensile deformation behavior of the ferritic steel containing both hard VC and soft Cu particles was compared with the results of VC or Cu single dispersion ferritic steels. The work hardening rate during tensile deformation is much larger in VC single dispersion steel than in Cu single dispersion steel. Since the interaction with dislocation is different between hard VC particle and soft Cu particle, the density of geometrically dislocations tends to be more increased in VC dispersion steel than in Cu dispersion steel, leading to the larger work hardening rate of VC steel. On the other hand, the multiple dispersion of VC and Cu particles leads to the significant increase in the yield strength as well as tensile strength without reducing ductility compared with the VC or Cu single dispersion steels. This is because a large work hardening rate is kept in spite of the high strength in the VC-Cu multiple dispersion steel.