Welding Errors

Abstract

Defects in welding are flaws, irregularities, and imperfections formed in a given weldment, compromising its intended use or aesthetic appeal. Irregularities that compromise the weld are classified as weld defects according to ISO 6520. In contrast, flaws that do not compromise the weld are classified as weld discontinuities. Their acceptable limits are under ISO 5817 and 10042.

Defects often vary in size, shape, and extent based on the metal structure and the welding process. The major causes are the wrong choice of welding method or incorrect welding patterns. However, many other causes may lead to specific flaws in a weldment.

Weld defects may occur inside or outside the metal, weakening the joints or affecting their appearance. While some flaws can be within permissible limits, others may lead to product rejection. Thus, it is essential to avoid weld failure.

A weld defect results from a poor weld, weakening the joint. It is defined as the point beyond the acceptable tolerance in the welding process.

Imperfections may arise dimensionally, wherein the result is not up to standard. They may also take place in the form of discontinuity or in material properties. Common causes of welding defects come from incorrect welding patterns, material selection, skill, or machine settings, including welding speed, current, and voltage.

When a welded metal has a welding defect present, there are multiple options for resolving the issue. In some cases, the metal can be repaired, but at other times the metal itself has melted and the welding procedure needs to be restarted.

Weld irregularities occur for a variety of reasons and it results in different welding defects. They can be classified into two major categories: internal welding defects and external welding defects.

Keywords: Welding defects, metal structure, welding process