| Defect | Explanation | Causes |
|---|---|---|
| Cracks | Cracks occur when localized stresses exceed the ultimate tensile strength of the material. They can be caused by factors such as poor ductility of the base metal, high sulfur and carbon contents, high arc travel speeds, a too concave or convex weld bead, and high hydrogen content in the weld metal. | Poor ductility of base metal, high sulfur and carbon contents, high arc travel speeds, too concave or convex weld bead, high hydrogen content in the weld metal |
| Porosity | Porosity is the result of gases being entrapped in the solidifying weld metal. It can be caused by factors such as flux or coating constituents of the electrode, shielding gases, absorbed moisture in the coating, and contaminants on the workpiece or electrodes. | Flux or coating constituents of the electrode, shielding gases, absorbed moisture in the coating, contaminants on the workpiece or electrodes |
| Lack of Fusion | Lack of fusion occurs when there is insufficient bonding between the base metal and the weld metal. It can be caused by factors such as too fast travel speed, incorrect welding technique, and insufficient heat. | Too fast travel speed, incorrect welding technique, insufficient heat |
| Slag Inclusion | Slag inclusion happens when slag from previous runs is not cleaned away or when there is insufficient cleaning and preparation of the base metal before welding commences. | Slag from previous runs not being cleaned away, insufficient cleaning and preparation of the base metal |
| Undercuts | Undercuts occur due to factors such as too fast travel speed, bad welding technique, and excessive heat build-up. | Too fast travel speed, bad welding technique, excessive heat build-up |
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Manufacturing processes
