Studies on stellite 6 hardfaced gate valve by plasma transferred arc welding process

Abstract

newlineWeld hardfacing is one of the surfacing process in which wear resistant material is deposited onto a carbon or low alloy steel base metal It is widely employed for fabrications and in the repair of valves and valve components for use in oil chemical and other innumerable industries However weld hardfacing lacks popularity due to certain limitations such as deterioration of geometrical mechanical metallurgical and tribological properties etc which are inherent to the welding process The present investigation addresses those problems and provides some solution to overcome those limitations In the present investigation stellite 6 was deposited on low alloy steel gate valves using Plasma Transferred Arc surfacing process Five factors five levels Central Composite Rotatable Design was selected for conducting the experiments The experiments were carried out as per design matrix by laying four linear bead and single circular bead on gate valves The hardfacings were analyzed by regression models to reveal the influence of significant process parameters such as welding current welding speed powder feed rate plasma gas flow rate and oscillation frequency on the geometrical mechanical metallurgical and tribological properties of the hardfaced gate valves newline