Topics on weld metal metallurgy

Abstract

In Electroslag welding of low carbon steel, the effects of electrode feed rate on weld geometry, welding velocity, energy input, weld macrostructure and the microstructure of the weld and HAZ were determined. Results showed that increasing the electrode feed rate at constant voltage had no significant effect on the penetration but increased the pool depth, decreased the shape factor and increased the encounter angle. The pool shape was approximately a paraboloid of revolution. Increasing the welding voltage at constant feed rate increased both pool depth and penetration, but had little effect on the shape factor. Standard and special metallographic etchants were used to study the transition region between the weld and the base metal, the average dendritic cell diameter, the pool shape and the mechanism of metal transfer from the base metal to the liquid poof as a function of the penetration; results were related to the welding parameters.