Scientific Journal of KubSAU

The main component of agricultural production is machinery, which is a complex technical system (harvesters, agricultural machines, tractors, cars, etc.). The practice of operation of technically complex machines shows that, in general, the process of replacing worn parts and working devices of agricultural machinery with new ones prevails, and the number of restored products is small. However, experience shows that the technological process of restoration of machine parts allows you to get high quality surfaces of such parts and reduce the cost of repair. One of effective methods of restoration of surface layers of details is gas-flame spraying with the subsequent laser reflow. The article presents the results of the study of the zone of thermal influence in steels U8A and St3, as well as the influence of laser reflow regimes on its microhardness in these steels. It is established that the higher the laser power and the lower the speed of movement of the optical head, the larger the size of the thermal influence zone. Conversely, the lower the power of the laser and the higher the speed of movement of the head, the smaller the size of the zone of thermal influence. The power of the laser and the speed of movement of the optical head slightly affect the value of microhardness. It was also noted that promising areas in the field of restoration of parts of agricultural machines laser welding are: a scientific rationale for the selection of powders; the study of regularities of changes of the microstructure parts, regularities of formation of layers; development of modes and justification of regimes of welding; and, ultimately, the development process of restoring the specific parts