High Temperature Plasticity of TP347H Stainless Steel Welded Joint Heat Affected Zone

Simulated Heat Affected Zone (HAZ) samples of TP347H stainless steel welded joint with 800-1380°C peak temperature thermal cycles were produced using Gleeble 3180 thermal mechanical simulator. 600°C constant speed tensile tests for simulated HAZ samples were carried out, and the precipitates of the simulated samples were analyzed by EDAX. The results show that the lowest Reduction of Area (RoA) was around 53% - 56% in 900-1150°C, which was about 15% lower than the maximum RoA in 800-1380°C. The reasons for decrease of HAZ high temperature plasticity were related to the precipitation of NbC. The fine NbC precipitated in the crystal and grain boundary enhanced strength of grain at high temperature, which resulted plastic deformation or slip at high temperature were mainly concentrated in the grain boundary, and high temperature plasticity of HAZ were decreased.