Proceedings of the Third International Conference on Metals & Hydrogen P65

The role of plastic strain on the delayed fracture behaviour of twinning-induced plasticity steels

Z.C. Luo (1)1

  • (1) 1

    Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong 00852, China

Abstract

The present work investigates the delayed fracture (DF) behaviour of a twinning-induced plasticity (TWIP) steel in the neutral environment by using deep-drawn cup specimens. The specimens are exposed to different neutral corrosive environment to observe the occurrence of DF. The fractography and thermal desorption spectroscopy (TDS) results show that the DF of the TWIP steel is caused by a hydrogen-assisted transgranular stress corrosion cracking (tSCC) mechanism. Besides the residual stress, we demonstrate that the plastic strain plays a crucial role on the DF of the TWIP steel by accelerating the crack growth rate due to the increased density of dislocation density and deformation twins.

Keywords

  • TWIP steel
  • Delayed fracture
  • Stress corrosion cracking
  • Plastic strain
  • Hydrogen

Introduction