THE EFFECTS OF PROCESS VARIABLES ON THE BEAD HEIGHT OF SUBMERGED-ARC WELD DEPOSITS

The results of bead height measurements for a series of bead-on-plate welds (heat input 3 kJ mm-1) are presented to determine the effects of the process variables on bead height for the submerged are welding process. It is found that the bead height is affected by the electrode polarity, electrode diameter, electrode extension, welding current, welding voltage and welding speed. A negative electrode polarity, a small electrode diameter, a large electrode extension, a high welding current or speed, and a small voltage encourage a large bead height in most cases. The effects of power sources (constant voltage or constant current) and fluxes (acidic or basic) on the bead height vary according to the current setting, electrode extension and electrode polarity used. Regression equations are presented for computing bead height from the welding parameters, using both linear and curvilinear multiple regression analysis techniques. The correlation coefficient of the linear multiple regression equations is better for the electrode negative polarity. However, for the electrode positive polarity, the correlation coefficient of the curvilinear multiple regression analysis is somewhat higher.