Effect of post-weld heat treatment (PWHT) on the intergranular corrosion of ENiCrFe-7 weld overlay cladding materials
By Guo, P. L.; Ling, L. G.
Published in Journal of Materials Research and Technology
2020
Abstract
Effect of post-weld heat treatment on the intergranular corrosion of ENiCrFe-7 weld overlay cladding materials was investigated. The results showed that Cr-rich precipitates occured in the dendrites and grain boundaries, and Cr-depletion areas appeared around Cr-rich precipitates. The degree of Cr-depletion in the dendrite was aggravated with the increase of PWHT time to 16 h, then it was gradually recovered with increasing PWHT time to 48 h. The results showed that as-weld Alloy ENiCrFe-7 was only susceptible to dendritic corrosion after EPR, the one heat treated after 615 ℃/16 h has more serious dendritic corrosion than that of as-weld Alloy, moreover, the less intergranular corrosion was also observed when the weld was heat treated at 615 ℃/16 h. Only the intergranular corrosion was exhibited in the one heat treated after 615 ℃/48 h. Howerver, Alloy ENiCrFe-7 has better corrosion resistant properties.