Proceedings of the Third International Conference on Metals & Hydrogen P68

Effect of hydrogen on nanomechanical properties of Fe-22Mn-0.6C TWIP steel during in situ electrochemical nanoindentation

Dong Wang (1)1 , Tarlan Hajilou (1)1 , Xiaofei Guo (2)2 , Afrooz Barnoush (1)1

  • (1) 1

    Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, N-7419 Trondheim, Norway

  • (2) 2

    Steel Institute, RWTH Aachen University, Aachen, Germany


In situ electrochemical nanoindentation (ECNI) has been used to study the effect of hydrogen on Fe-22Mn-0.6C TWIP steel at different potentials. Two grains with different orientations have been tested in this study. The pop-in load, pop-in width and nano-hardness data were extracted and analyzed. It is clearly shown that pop-in load and width were reduced while hardness was increased by charged hydrogen for both grains. Higher cathodic potential causes higher hydrogen concentration leading to a more obvious change of nanomechanical properties. It is proposed that the homogeneous dislocation nucleation (HDN) was reduced and dislocation mobility was limited by the dissolved hydrogen. In addition, the results also show that (110) grain has a higher hydrogen sensitivity than (100) grain.


  • TWIP steel
  • Electrochemical nanoindentation
  • Hydrogen embrittlement
  • dislocation nucleation
  • nano-hardness