During the welding process of spiral steel pipes, gas spaces may exist on the surface of the weld or within the weld itself. This defect is known as porosity. The primary cause of porosity defects is the unclean surface of the weld, which may contain moisture or rust. During welding, under the influence of high welding temperatures, impurities such as moisture begin to evaporate. Due to the slow evaporation of moisture or rust, cavities form in the molten metal. These cavities represent gas defects in the welding process. Especially during groove welding, incomplete cleaning of the groove can more easily lead to gas defects. The presence of gas defects seriously affects the welding quality of the weld, as it reduces the volume that should be welded, causing the welding metal to not completely fill the weld, thereby decreasing the weld's strength and making it prone to cracking.
To better address porosity defects in spiral steel pipe welding, it is necessary to treat the weld surface based on the understood principles of porosity formation. This can effectively eliminate the influence of impurities such as moisture and rust on bubble formation. From a welding perspective, it is also necessary to adjust the welding parameters so that the welding current and welding speed meet the welding requirements, thereby reducing the probability of porosity defects. Furthermore, full-process welding inspections are required. Starting from the arrival of raw materials, proper storage and preservation measures should be taken. Storage methods should be adopted according to the characteristics of the welding steel plates to ensure they are stored in a good environment, thereby avoiding phenomena such as rusting. Carefully inspect the processed steel plates, especially the welding areas, which require more in-depth inspections. Through inspections, potential problems can be identified and promptly addressed, improving the cleanliness of the welding areas and effectively avoiding the occurrence of bubble defects.
