Influence of Nb addition on the particle coarsening and microstructure evolution in a Ti-containing steel weld HAZ

The effect of Nb addition on particle coarsening and microstructure in a Ti-containing steel weld HAZ (heat affected zone) is investigated. Compared to TiN particles, the high temperature stability of the (Ti, Nb)(C, N) complex particle is deteriorated by the addition of Nb. Particle coarsening occurred more easily, and then the austenite grain grew larger in the coarse grained heat affected zone (CGHAZ) due to the decrease of pinning effects by particle.