Influence of Welding Position on Tribological Behavior of SS-309L Cladded Surface on 9Cr-1Mo Steel

Abstract

Welding position is a significant parameter for weld hardfacing operations applicable to engineering valves, coal transmission pipes in thermal power plants, mining industries, etc. Weld deposition is conducted with horizontal (1G) and vertical (3G) positions due to appropriate orientation of various engineering products. However, parameters like current, speed, travel angle, etc. are different for both welding positions. Therefore, it is required to investigate the influence of these two welding positions on tribological characteristics. In the present work, 1G and 3G weld positions are considered for SS-309L weld hardfacing on 9Cr-1Mo substrate material using flux cored arc welding (FCAW) process. Weld deposited surfaces are subjected to essential mechanical and metallurgical characterizations. Results confirm that the surface deposited using 1G position has higher slurry abrasive wear resistance (0.036 gms), lower dilution (14 %), and lower heat affected zone (HAZ) width (1.5 mm) which is significantly better than 3G position. SEM analysis shows fine elongated grains which precipitate from Cr element as nucleation site for the growth resulting in an improved eutectic matrix within fine grain structure. Wear resistance is improved in 1G position due to uniform elemental distribution of Fe and Cr observed with EDS analysis. Hence, 1G position is the best suitable position for weld hardfacing operations.