Micromechanism of Cr, Ni and W alloying process in nitriding process of 1Cr11Ni2W2MoV stainless steel: First-principles calculation

The influence of alloying elements on plasma nitriding keeps mysterious right now. Combined by first-principle calculation and orthogonal experimental design methods, the micromechanism of Cr, Ni and W alloying process in nitriding process of 1Cr11Ni2W2MoV stainless steel was systemically studied and characterized. It is found the factor element plays the key role in affecting the structural stability of Fe(X) phases, including nitrogen absorption and penetration processes. The content of alloying elements acts the weakest influence on nitriding process among four factors as element, surface index, content, and alloying layer. Comprehensive consideration on the structural stability and activation energy, the optimized compound in nitriding process is α-Fe(110)Ni3N. Electronic structure shows its smallest activation energy originates from its weak interaction between N and Ni. And the Ni–Ni bond has weak interaction with each other. So the N atom can easily penetrate the Ni–Ni wall to overcome small activation energy. This study opens an avenue to optimize plasma nitriding designing in stainless steel.