MAIN DEFECTS OF WELDED JOINTS

Abstract

The construction and reconstruction of existing pipeline networks in Ukraine today is directly related to improving welding methods. Therefore, ensuring welding quality and preventing weld defects is paramount. Therefore, ensuring welding quality and preventing weld defects is of great importance. This study aims to identify the causes of defects in welded joints, as these significantly impact the strength of welded joints and can lead to the premature failure of structures. Materials' susceptibility to cracking is determined by their properties, and the design of the joint affects its type and load capacity, as well as its susceptibility to the formation and development of cracks, stress concentrators and residual stresses. Various defects in welds may occur during welding work. Therefore, it is necessary to be careful and correct them in a timely manner. Some defects will not affect the integrity of the work, while others can weaken the structure or product and lead to breakdowns or accidents. Welded joint defects are deviations from the specified joint parameters during welding. These deviations result from violations of the requirements for welding materials, preparation, assembly, and welding of parts; thermal and mechanical treatment of welded joints; and the structure as a whole. Any type of weld defect increases the risk of failure. The main causes of defects are violations of processing technology, improper preparation of edges, the presence of delaminations, cracks in the welded metal, poor weldability of the base metal, mismatch of the chemical composition and properties of the filler material, violation of welding modes, improper use of equipment, low qualification of the welder. Defects arising as a result of welding can lead to serious accidents and structural damage. Without exaggeration, someone's life may depend on the quality of the weld in the future, so it is important to avoid production defects and understand the mechanisms that can cause them.