Jivkov's articles
Meso-scale mechanical model for intergranular stress corrosion cracking and implications for microstructure engineering
Abstract
The resistance of polycrystalline materials to intergranular cracking can be influenced by the microstructure. In sensitised stainless steels, for example,
the grain boundaries prone to sensitisation form paths of low resistance for intergranular stress corrosion cracking. The non-sensitised grain boundaries,
such as twin boundaries, have been observed to encourage the formation of crack bridging ligaments. Computational models of intergranular cracking have been
developed to investigate the consequences of crack bridging, through its effects on crack propagation in microstructures with different fractions of
non-sensitised boundaries. This paper introduces the recently developed two-dimensional model for intergranular cracking with crack bridging, and reports
its application to investigate the effect of grain size. It is shown that the size of the crack bridging zone depends on the grain size, and the shielding
contribution depends on the relative size of the bridging zone compared to the crack length. It is concluded that both grain refinement and increase in the
fraction of resistant boundaries can improve microstructure resistance to intergranular cracking. These observations are consistent with the effects of grain
boundary engineering on stress corrosion cracking resistance in sensitized stainless steels.