Microscopic Evaluation of Hydrogen Induced Crack Initiation and Propagation in Multiphase Steels

01 January 2015 → 31 December 2018
Regional and community funding: IWT/VLAIO
Research disciplines
  • Engineering and technology
    • Destructive and non-destructive testing of materials
    • Metals and alloy materials
hydrogen induced cracking microstructure High-strength steels EBSD
Project description

Hydrogen in metals often leads to the degradation of the mechanical properties and can lead to the unexpected failure of industrially relevant materials. The industrial applicability of high-strength steels (HSS) is limited due to their high sensitivity to hydrogen embrittlement. These steels show a high strength/stiffness vs. weight ratio, which makes them very interesting for the automobile industry and numerous structural applications. For safety reasons these materials can, however, not be employed to their full potential as long as the hydrogen problematic is not understood and solved. The goal of this PhD is to obtain a deeper insight in the mechanisms acting for hydrogen crack initiation and propagation in certain HSS. Because industrial HSS are very complex materials, fundamental knowledge was first acquired for low-carbon steel and generic Fe-C-X alloys with relative simple microstructures. Moreover, the hydrogen degradation behavior of complex industrial alloys, i.e. TRIP steel and pressure vessel steel, was evaluated. Advanced characterization techniques, with the focus on EBSD (electron backscatter diffraction), were used to reach the set goal. EBSD allows to investigate thoroughly a material, both microstructurally as crystallographic. By studying these different materials the influence of different microstructural features on the hydrogen induced degradation resistance was evaluated.