Technology for manufacturing test machine and specimens to study the defects effect on weld seams mechanical properties

The main material in the construction of hull structures of ships is shipbuilding steel. In shipbuilding and ship repair, welding plays a key role in forming the joints of steel structures. Every vessel in the Russian Federation is undergoing an inspection. During the inspection, the technical condition and compliance of the vessel with safety requirements are checked. During the inspection of body elements, especially welded joints, defects are often found, characterized by a violation of the continuity of the weld metal, while their parameters go beyond the limits established by regulatory documents. If the permissible standards are exceeded, the defects must be removed according to the factory's technology, and the welds must be repaired. Repair of defective areas leads to an increase in repair time, as well as an increase in the labor intensity and cost of repairing or building the ship's hull. The question becomes relevant: to eliminate the found defect or to allow the construction to be operated. The technology of manufacturing samples for conducting experimental research is considered. The choice of material, dimensions and shape for the manufacture of samples, as well as the technological parameters of the manufacturing process, are justified. The method of obtaining internal defects in a welded joint is described. According to the results of radiographic control, welded samples with an internal defect were identified, as well as control samples without defects. An experimental fatigue testing facility has been designed and constructed, which makes it possible to reproduce the necessary conditions. In addition to the installation, a computer program has been developed that allows you to count the number of cycles before the sample is destroyed, as well as read the corresponding deflection of the welded joints.