ABSTRACT
Non-metallic inclusions are always present in welds made by any fusion welding method. Composition of non-metallic inclusions, their quantity, size, shape, and distribution in the weld may have a marked effect on the mechanical properties of a welded joint. The major part of non-metallic inclusions contained in the weld are of an endogenous origin. Non-metallic inclusions contained in the weld may have a substantial effect on mechanical properties of a welded joint. The presence of non-metallic inclusions in the weld metal can favor formation of other defects as well. Formation of non-metallic inclusions may take place at lower oversaturations, if two or more components simultaneously participate in the formation of a nucleus. Growth of nuclei of non-metallic inclusions formed in the molten metal may take place either as a result of adsorption of ions from the melt because of oversaturation, or as a result of joining of individual fine inclusions at their collision.
