Publication

Abstract : In order to solve the heat transfer model of GTA welding process, the physical and the thermal properties of the workpiece, the heat source efficiency and the area of heat incident on the workpiece surface are required. In this work, the arc dimensions were measured experimentally with respect to current, speed, electrode tip angle and electrode distance for autogenous GTA welding. The arc parameters were fitted against welding variables using regression analysis. The projected arc area is found to increase with current and electrode distance and to decrease with electrode tip angle whereas it is found to be independent of speed. The shape of the projected arc area is observed to be semi-circular in the front and semi-elliptical in the rear for moving heat source. The regression equation developed can be readily applied in estimating the area of heat incident for solving the heat transfer equation. Copyright © 2013 Inderscience Enterprises Ltd.