Weld defects slag inclusions

The integrity of welded stmctures depends on the integrity of the welds, and much attention is given to testing methods, such as destmctive tests, nondestmctive tests, and general weld inspection. An objective of many tests is to determine whether welds contain specific defects, such as porosity, slag inclusions, cracks, or lack of fusion (14,15). 

Often contain defects (hydrogen cracks, slag inclusions, stop-start marks). Help initiate fatigue cracks. Critical welds must be tested non-destructively and defects must be gouged out. 

Defects revealed by visual inspection, possibly enhanced by DP and MP, include cracks, undercutting, surface porosity, surface slag inclusions, craters, residual slag, incorrect weld reinforcement profile and misalignments. Defects detected through the weldment thickness by volumetric techniques can include cracks, lack of penetration, lack of fusion, porosity, slag inclusions and laminations. 

A sporadic case, mentioned for comprehensiveness, is slag inclusion due to its entrapment in the hollow created between the second bead and the bevel wall if this, in the section at 30°, has not been completely filled. To be more clear, if you start to weld with wire before filling the bevel section at 30° with the electrode, this could cause defects (even lack effusion). 

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