Hot Corrosion of Weldments

Hot corrosion of the weldment is the result of the reaction between oxidation and sulfidation, which affects welded joints exposed to combustion gases containing sulfate coal ash at high temperature. It is also demonstrated that welding processes, weld consumables, temperature of exposure, and mixture of salt environment are important factors in hot corrosion of the weldment

Mechanical Characterization of Monel 400 and 316 Stainless Steel Weldments

AbstractDissimilar combinations of Monel 400 and austenitic stainless steel AISI 316 is widely used in the petrochemical, nuclear industries where the weldments are usually subjected to hot corrosion. This paper deals with the assessment of metallurgical and mechanical properties of these bimetallic joints obtained by Gas Tungsten Arc Welding process using ERNiCrMo-3 filler metal. A detailed structure- property relationship was made on these bimetallic joints using the combined techniques of optical microscopy, SEM/EDAX analysis

Effect of grain boundary precipitation on the mechanical integrity of EBW joints of Inconel 625

The precipitation effects on the mechanical behavior of electron beam welded joints of Inconel 625 in the as-welded [AW] and post-weld heat treatment [PWHT] conditions have been investigated in this research study. A PWHT comprising of direct aging [DA] treatment at 700 °C for 100 h in vacuum at a pressure of 10−5 mbar was performed on the weld joints. The microstructure of the base alloy opined the precipitation of MC system carbides and γ′′ strengthening phase after subjecting to DA. Also, Nb–Mo rich precipitates and the Laves phase was noticed in the inter-dendritic arms of the fusion zone (FZ) of welded joints in the AW conditions. DA treatment has a notable effect on the weld mechanical characteristics of Inconel 625 joints. The precipitation of γ′′ strengthening phase is reasoned for the significant rise in the yield strength [YS] and tensile strength [TS] of the base alloy and EBW joints