STUDIES ON WELD SURFACING DEVELOPED BY RE MODIFIED ELECTRODES

Abstract

I-lardfacing by welding most economic way to enhance the life of the components exposed to severe working conditions as a result of which its use increasing rapidly. In this study, six different types of flux compositions were prepared to study the effect of alloying elements (C, Cr, V, and Nb ) on microstructure, hardness and wear behavior. Low carbon steel was used as a substrate. Flux was prepared using FeCr, FeV, FeMo, Nb and Ceo2. Shielded metal arc welding procedure was used for the deposition of hardfaced layers onto the substrate. Rutile type 6013 iron based electrode was used to deposits were made using pre-placement technique to incorporate the alloying elements into the weld deposit in which flux with I and 1.5mm thickness was laid onto the substrate and weld bead developed. After weld deposition, specimens were prepared to analyze the abrasive wear behavior and hardness of the weld overlays. Microstructural characterization was done using optical microscope and SEM. SEM of worn surfaces was also done to reveal the material removal mechanism. EPMA analyzer was used to show the elemental distribution on weld overlays. An attempt to relate the microscopic behavior and macroscopic behavior with alloying elements was made in this work. 1P Increase of chromium % as the alloying element in the weld zone become finer and dendritic growth increases. Weld surfacing of Fe-Cr-Mo-Nb-V flux developed using Dc 175A was found optimized resulted in more hardness and wear resistance. Addition of V in Fe-Cr-C hardfacing flux increases hardness and wear resistance further by 1.5 to 2 and 3 to 4 fold respectively. IWHT of Fe-Cr-V weld surfacing shows adverse affect on the hardness and wear resistance. Type and magnitude of welding current affect hardness and wear resistance