Welding defects and welding quality of SSAW steel pipe

　　What is the welding qulity of SSAW steel pipe? It is the the degree to which the welding product meets the design technical requirements. Pipe manufacturer usually ensure the welding qulity of SSAW steel pipe by design quality, processing quality, quality inspection, post-weld treatment, etc., since the welding quality not only affects welding products's use performance and life, it also affects personal and property safety.

　　Welding quality usually appears as welding defects, that includes external defects and internal defects. External defects refer to excess height does not meet the requirements, welding tumor, undercut, crater, arc burns, surface pores, surface cracks, welding deformation and warping. Internal defects refer to cracks, not penetration, not fused, slag and porosity.

　　How to prevent the appearance of welding defects to ensure the welding quality?

　　1. Welding method should be suitable for the characteristics of components, and its economical efficiency should be good. The welding process should be able to minimize stress, deformation and stress concentration. Production labor and material consumption should be as small as possible, the convenience of flaw detection should also be taken into consideration when design the joint. The type of joint used in the welding product and its calculated strength should meet the actual carrying capacity.

　　2. The performance of the base metal, wire, flux or welding electrodes and other welding materials those adopted by pipe manufacturer should meet the design requirements. The performance of welder, auxiliary equipment and testing equipment should be good. Before welding, the welding material should be dried according to the provisions, the welding groove of workpiece should meet the requirements and remove the cutting residue, cracks and dirt.

　　3. Pipe manufacturer should carry out quality inspection through the whole production process from design to finished product, we must ensure that the test method used in the quality inspection process is rationality, the reliability of the testing instrument and inspection staff technical level. We should use various inspection methods to test the properties of the joints, physical properties, mechanical properties, microstructure, chemical composition, corrosion resistance, appearance dimensions and welding defects of products after welding.