What is welding defects? Welding defects may be define as a discontinuity or discontinuities that failed to meet the minimum acceptance per standard or specifications. Defects may occurred in excessive conditions, outside the acceptance limits which risks to compromise the stability or the functionality of the welded structure. They are also acceptable discontinuities, the same type of discontinuity of a lesser degree, might be considered harmless and acceptable.
Weld defects happen for a host of reasons. Air may creep into the weldment to cause porosity. The wrong amount of heat can cause cracking. Bad welding technique can cause undercuts or incomplete penetrations of one kind or another.
Various factors contribute to weld problems, but many lead back to the same place. In fact, most causes of weld defects can be traced back to two general areas: first, a combination of poor instruction and workmanship; second, poor weld design and/or material choice.
Linear Indication: Any indication with length greater than three times the width. Linear indications are mainly cracks, lack of penetration, lack of fusion, and elongated slag inclusions.
Rounded Indication: Any indication with the length equal to or less than three times the width. A rounded indication may be of circular, elliptical, conical, or irregular in shape and may have tails. While determining the size of an indication, the tail shall also be included. Rounded indications may appear on radiographs from any imperfection in the weld, such as porosity, slag, or tungsten.