Mass and heat flow in welding

Abstract

The character of heat flow in welding determines the nature of the weld thermal cycle and hence, in the case of transformable alloys, the microstructure of the weld metal and heat-affected zone. Mass flow, which encompasses the flow of plasma in the arc column, the flow of metal from electrode to weld pool, and the flow of metal in the weld pool itself, has less influence on the metallurgy of the joint. Irregularities or instabilities in mass flow may, however, limit the usefulness and range of application of specific processes and may cause irregularities in the heat-flow pattern.