Agata Wieczorska

The article describes an innovative post-weld surface finishing method, which is characterized by moving a specialized cutting tool along a butt weld. The aforementioned method is unique for the machining allowance, which is treated as the weld bead height and is removed in one step with one pass of the cutting tool. The tool is equipped on one side with linearly arranged tooth-shaped cutting elements, with the adjacent teeth height changing and increasing according to the direction of the feed. The non-standard geometry of the cutting tool enables the finishing of a heterogeneous post-weld surface with increased hardness. The results of studying the 2D profile parameters and the 3D stereometric characteristics of the surface roughness using the optical method are presented in the article. Test samples were made of S235JR steel and butt welded with the MMA, MIG, and TIG methods. Subsequently, the welding bead was ground and finished in accordance with the innovative method to flush the bead and the base metal’s surface. Additionally, residual stress analyses were performed using the X-ray diffraction method in the surface layers of the test samples. Based on the conducted research, the influence of the innovative finishing method on the surface quality is described.

This paper presents the issue of welding technology qualification using the example of structural steel S355JR with a plate thickness of 25 mm and 100 mm, bevelling V. The main objective of this work was to attempt to perform a full qualification of the submerged arc welding process in accordance with the requirements of PN EN ISO 15614. Particular attention was paid to the issue of the qualification of welding technology. The samples were subjected to non-destructive testing, i.e. visual and penetrant testing, as well as ultrasonic testing and heat treatment. This was followed by destructive testing, including macroscopic testing and hardness testing. According to the proposed procedure for the recognition of submerged arc welding technology, once the necessary tests had been carried out and the protocols with positive results had been obtained. The documentation had been completed, the analysis needed to obtain certificates of conformity for factory production control and welding quality was carried out.Submerged arc welding is often used for highly responsible butt joints, particularly when joining thick components. This has been achieved through the proper design of the preparation of the parts to be welded and the development of a welding technology that practically eliminates the pre-phase that occurs in traditional technology, thereby eliminating the risk of it affecting the quality of the welded joint.During the implementation of submerged arc welding, a number of technological problems were encountered. The first test joints contained many defects, i.e. sticking and slag inclusions inside the welds. In addition, obtaining welds with the correct profile and removing the slag from the weld groove was difficult. These obstacles were eliminated experimentally by carrying out successive tests using different parameters and welding groove geometries.The correct implementation of any welding process depends on its input parameters. These parameters include welding current, welding speed, welding current, wire diameter, welding voltage and many others. Submerged arc welding (SAW) is widely used in the industry for manufacturing as it is more reliable, provides deep penetration in the work, ensures a smooth finish on objects, and results in high productivity.The technology was developed for a company that manufactures control discs for steam turbines.