Cracks that occur between the liquidus and the soli­dus are commonly termed ‘hot cracks.’ Hot cracks can be further differentiated depending on whether they occur in the composite region of the weld bead on cooling (solidification-type) or in the partially melted or heat-affected zone where a composition gradient or low melting phase acts to locally depress the solidus of the alloy (liquation-type). Additionally, a third type of‘hot cracking,’ that is, hot tearing, can be
distinguished from solidification and liquation cracks. Hot tears are primarily mechanical in nature, driven by the geometry and stresses in the weldment. A schematic of the locations and representative micrographs of the different types of supersolidus cracking are shown in Figure 2.