Welding is commonly used to connect two or more pieces of metal together. Whether it is MIG welding (gas shielded welding), TIG welding (tungsten gas shielded welding), shielded metal arc welding (SMAW), or flux cored flux welding (FCAW), if appropriate techniques are not used, some problems may be encountered.

1. Welding spatter

When droplets form near the welding arc, spattering occurs. It is usually caused by high currents, incorrect polarity, or insufficient gas shielding. To avoid this situation, reduce the current and arc length, and increase the angle from the welding gun to the electrode plate. Cleaning the gas nozzle can also help.

2. Porosity

These defects are caused by the absorption of hydrogen, nitrogen, and oxygen in the molten pool. After solidification, they are trapped in the weld. Grease, moisture, paint, and rust can also cause air holes. To prevent this problem, ensure that the edges of the plate are clean and dry, use new welding materials, and check the welding gun for leaks.

3. Reverse buckle

Tripping occurs when high voltage or long arc lengths are used. The use of incorrect electrodes or electrodes that are too thick relative to the thickness, as well as the rapid movement speed of the welding gun, can also cause this problem. This problem can be avoided by using electrodes of the right size, ensuring slow movement of the welding gun, and avoiding proximity to the vertical plate if horizontal fillet welding is being performed.

4. Crack

When the internal stress is greater than the strength of the weld or base metal (or both), cracks may form on the weld. They may spread over time and must be addressed immediately. These defects can be avoided by carefully cleaning, polishing, and deburring the edges of the metal plate, so that they can bond well together. It is also helpful to ensure proper temperature while reheating both sides of the joint.

Other common problems on the surface of metal plates