WELD DEFECTS AND TESTING
In welding, the defects often found in fusing due to lack of fusion, lack of penetration, inclusion of slag or oxide, presence of cracks, porosity and uncut and excessive penetration. These are the defects generally shown in butt welds.
The defects like cracking, lack of fusion, porosity, slag inclusion, bad profile and oxide inclusion alters the static strength of the welded joint under ductile conditions but have a serious consequences if the joint is subjected to fatigue loading. The presence of crack enhances the probability of brittle fracture. Similarly a lack of fusion causes a lack of discontinuity and hence diminishes the fatigue strength.