Abstract: A process, termed Trailing Edge Stress Relief (TESR) is described which can be used to produce a weld joint with reduced residual stress level with least defects. In this process, cyclic stresses are applied to the trailing edge of the weld (TEW) during welding. Welding operation is always in quasi-stationary state; but in the TEW microstructure is in formative stages. Therefore TEW is in the Second order Quasi Stationary (SQS) state. During the time solidification of the cup of molten metal takes place, in TESR process cyclic stress is applied that modifies the structure of microstructure. The modification of the structure of microstructure reduces the grain size and the potential energy that is otherwise retained after solidification in it, as residual stress. In the process described pneumatic vibrators are used; but such cyclic stresses can be generated by other devices using electrical, electronic, magnetic or ultrasonic energy; and systems can be designed using combinations thereof.

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.