EFFECTS OF ALLOYING ELEMENTS ON α-Fe(100)/Cr(100) INTERFACE

Abstract

The [Formula: see text]-Fe(100)/Cr(100) interface has an important effect on the precipitation of the Cr-rich phase in ferritic stainless steel, and alloying elements affect the stability of the [Formula: see text]-Fe(100)/Cr(100) interface. However, it is difficult to clearly understand the effect of alloying elements on the [Formula: see text]-Fe(100)/Cr(100) interface behavior experimentally. Therefore, the first-principles calculation is employed to address this problem in this paper. First of all, the segregation behaviors of alloy elements (Mo, Nb, and Si) on the [Formula: see text]-Fe(100)/Cr(100) interface were systematically investigated. And then, the effects of these alloying elements on the property of the [Formula: see text]-Fe(100)/Cr(100) interface were studied. Based on the density functional theory, the work of adhesion ([Formula: see text]), interfacial energy ([Formula: see text]), doping energy ([Formula: see text]), and electronic properties of the [Formula: see text]-Fe(100)/Cr(100) interface were analyzed. The results show that the body-centered [Formula: see text]-Fe(100)/Cr(100) interface is constructed by using seven layers of [Formula: see text]-Fe(100) and Cr(100) surface models. The [Formula: see text] is 6.115 J.m[Formula: see text], and the [Formula: see text] is − 0.12 J.m[Formula: see text]. The doping atoms tend to segregate on the surface of [Formula: see text]-Fe(100). When the Si atom doped in the interface, the [Formula: see text] increases, and the [Formula: see text] reduces. The doping of the Si strengthens the bonding strength of the interface and promotes the nucleation of the Cr-rich phase. While the addition of Mo and Nb atoms decreases the [Formula: see text] of [Formula: see text]-Fe(100)/Cr(100) interface, increases the [Formula: see text]. The bonding strength of the interface is weakened and the nucleation of the Cr phase is inhibited. Based on this result, it is clearer to understand the effect of Mo, Nb, and Si atoms on the precipitation of the Cr-rich phase in ferritic stainless steel.