During the welding process, porosity is a common welding defect that not only affects the appearance of the weld but also seriously weakens the strength and sealability of the welding joint, thereby affecting the overall performance of the welding structure. The formation of porosity is mainly related to the failure of gases in the melt pool to escape in time. In the process of arc welding, to avoid the occurrence of porosity, it is necessary to start from multiple aspects such as welding technology, material selection, and operation methods for systematic control.



Firstly, controlling the welding environment is one of the important measures to avoid porosity. Moisture and dust in the air are easy to form gases in the welding area, especially in humid environments, where the surface of the weldment or the welding rod becoming damp can lead to the formation of porosity. Therefore, welding operations should be carried out in a dry, well-ventilated environment, and dehumidification equipment can be used as necessary to reduce air humidity.

　　Secondly, choosing the appropriate welding material is also crucial. Welding rods and wires should be selected according to the type of base material and welding process requirements, and attention should be paid to whether the welding rod has been dried. Undried welding rods contain more moisture, which, when heated during welding, decomposes into hydrogen and oxygen, gases that are easy to remain in the melt pool and form porosity. Therefore, welding rods should be dried according to regulations before use and stored in an insulating cylinder to prevent re-moistening.

　　Thirdly, optimizing welding parameters is also a key to preventing porosity. The selection of current, voltage, and welding speed should be reasonably matched. Excessive current can easily cause the melt pool to overheat, making it difficult for gases to escape; insufficient current, on the other hand, can lead to insufficient melt pool energy, resulting in poor fusion. Too fast welding speed can cause the melt pool to cool too quickly, with gases not having enough time to escape; too slow speed can lead to an excessively large melt pool, increasing the possibility of gas dissolution. Therefore, appropriate welding parameters should be adjusted according to specific conditions to ensure a stable melt pool and the complete escape of gases.



In addition, good operating habits and welding techniques should not be overlooked. The welder should maintain a stable arc length during the operation process, avoiding the air being drawn into the melt pool due to an excessively long arc. At the same time, the correct welding angle and wire feeding method should be adopted to ensure that the melt pool is fully covered and the weldment area is protected, reducing the possibility of gas intrusion.



Finally, the cleaning treatment of the weldment surface should not be ignored either. Before welding, it is necessary to remove oil, rust, paint, and moisture on the surface of the weldment, as these impurities will decompose into gases at high temperatures, increasing the risk of porosity. Cleaning methods such as sandpaper grinding, wire brush cleaning, or organic solvent cleaning can be adopted.



In summary, to effectively avoid porosity defects in arc welding, it is necessary to comprehensively consider multiple aspects such as welding environment, material preparation, process parameters, operation skills, and surface treatment of the weldment. Only through scientific and reasonable welding management and standardized operation procedures can welding quality be guaranteed, welding efficiency be improved, and the safety and reliability of the welding structure be ensured.