Effects of exposing temperature on corrosion performance of weld joint of a Ni-Mo-Cr alloy

Corrosion tests of weld joint of a Ni-Mo-Cr alloy were performed in a eutectic LiF-NaF-KF molten salt for 400h at different temperatures (550 degrees C, 700 degrees C, 850 degrees C). Results indicate that the joints exhibit Cr depletion and Fe enrichment in corrosion layer at 700 degrees C and 850 degrees C, that the structural differentiation caused by welding has little impact on the diffusion of the elements in the alloy. The thickness of the Cr depleted layer induced by the corrosion in the molten salt increases with the temperature. The grains of the alloy sample become coarser due to the annealing at higher temperature, which may also enhance the corrosion of the alloy in the salt. (C) 2015 Elsevier B.V. All rights reserved.