Proceedings of the Third International Conference on Metals & Hydrogen P19

Effect of alloying on the hydrogen-enhanced decohesion (HEDE) in steel and Ni-base alloys

Vsevolod I. Razumovskiy (1)1 , Shuang He (1)1 , Anastasiya S. Kholtobina (1)1 , Werner Ecker (1)1

  • (1) 1

    Materials Center Leoben Forschung GmbH (MCL), Roseggerstraße 12, A-8700 Leoben, Austria

Abstract

The hydrogen-enhanced decohesion (HEDE) mechanism of hydrogen embrittlement (HE) is based on the idea of the metal-metal bond weakening in the material due to the presence of hydrogen in the lattice. We focus on this mechanism as the first step toward development of new H-resistant steels and Ni-base alloys and we choose density functional theory (DFT) as one of the best suitable methods to study HEDE at the atomic level. We apply DFT calculations to an investigation of the effect of H on the cohesive strength of both bulk and interfaces of the alloys matrix phases and study a possibility to reduce the embrittling effect of H by means of alloying. In addition, we demonstrate a way to use the results of the DFT calculations to describe the effect of alloying on the HEDE in multicomponent alloys in the framework of a model based on the results of the DFT calculations of segregation energies, interface strengthening energies and partial molar cohesive energies in the dilute limit.

Keywords

  • first principles calculations
  • segregation energy
  • hydrogen embrittlement
  • steel
  • Ni-base alloys

Introduction