Inventors:
Madhavji A. Unde - Sacramento CA
International Classification:
B23K 918
Abstract:
A process, called Covered Trailing Edge of Weld (CTEW) that can be applied during fusion welding that produces a weld without cracks and porosity and reduced residual stress level, is described. The process eliminates or reduces the need of non-destructive testing, re-work and post weld heat treatments in weld manufacturing. It is known that in a normal unassisted solidification of a weld, numerous cooling gradients from solid-liquid interfaces come into effect, because of numerous and multi-directions of solid crystal faces that promote crystal growth in solidifying metal in different direction. Such micro cooling gradients in molten metal are in various directions also because of varying inclinations of the surface of the cup at each point where solid base of microstructure is exposed for crystal growth. Resultant growth direction of mass of crystals/grains is determined by direction of welding, gun angle, inclination of cup surface on which crystals grow at each point and applied directions of heat conduction. Different directions of neighboring crystals thus grown at the interface, generate complex micro structure which may be dense with several entanglements or with voids which may capture gas.