ОСОБЕННОСТИ ТЕХНОЛОГИИ ЛОКАЛЬНОЙ ТЕРМИЧЕСКОЙ ОБРАБОТКИ СВАРНЫХ СОЕДИНЕНИЙ

Heat treatment of welded joints is an integral part of the production cycle of large-sized metal structures, as it allows you to purposefully reduce residual mechanical stresses in the metal arising during technological operations. Among the main factors affecting the magnitude and nature of residual stresses, we mention the modes of casting processes and machining workpieces by cutting and pressure. Deformations in the metal can exceed the maximum permissible values and, in the absence of proper heat treatment, lead to cracking and subsequent destruction of the structure. In the case of large-sized products, the problem of heat treatment of welded joints also arises: overheating of nearby elements occurs, which requires additional costs for their cooling and control.To solve this problem, specialized technologies of local thermal exposure are used to minimize temperature loads throughout the structure. Local induction heat treatment does not provide uniform heating of a large structure, electron laser heat treatment is not the final operation, and laser heat treatment with a defocused beam creates a risk of overheating of the heat treated object.The development of technology and device for local heat treatment of welded joints of large-sized metal structures, devoid of the listed shortcomings, was the purpose of the study. The proposed technology and device make it possible to do without standard heat treatment of welded joints in an electric furnace. Their advantage is to reduce the risk of overheating of adjacent elements, reduce the cost of cooling and subsequent control, increase the quality and reliability of welded joints, the ability to adjust the exact parameters of heat treatment. The introduction of this technology and device in the production process will reduce the risk of defects in welded joints due to their improvement, which is especially important in the case of large-sized structures. This results in a more uniform distribution of heat in the welding region and a reduced likelihood of overheating of the metal, thereby providing the required weld strength by minimizing undesirable changes in material structure.