Effect of Si and P elements on the stability of Fe2Mo-Laves phase in ferritic stainless steel

Abstract

It is of great significance to study the nucleation mechanism of Si and P elements in the Fe₂Mo-Laves phase to control their precipitation and improve the strength of steel. Based on the first-principles calculations, the effects of Si and P elements on the stability of Fe₂Mo were studied. The addition of Si and P greatly increases the possibility of its formation in steel. When the Si and P concentrations are 37.5 %, the formation energy is the lowest. Si and P elements improve the stress deformation resistance and the stiffness of Laves phase, which makes Laves phase more stable in high-temperature environment. The addition of Si and P significantly improves the kinetic stability of Fe₂Mo, but the improvement effect of P is not as good as that of Si. This study provides theoretical guidance for controlling the precipitation of the Fe₂Mo-Laves phase in practical production.