Metallurgy of Welding, Brazing and Soldering -
The study of welding metallurgy IS very important because the over all mechanical properties, of a weldment are determined by the characteristic properties of the individual microstructure present in the weld deposit and the weld heat affected zone.
It has long been recognized that one of the major problems associated with fabrication by welding arises from the inability to obtain uniform mechanical properties throughout the weldment. Even extensive postweld heat treatments fail to eliminate this weld induced variability in mechanical properties.
Both chemical inhomogeneity and changes in metallurgical structures are known to result during welding operation because most fusion welding processes generate high rates of heating and cooling in the weld metal and parent metal adjacent to the weld:
