Magnetic fields in the workplace during the operation of contact spot welding installations

Abstract

Contact welding is one of the most common types of welding. According to the technological method of obtaining joints, contact welding can be spot, relief, butt, suture. Spot contact welding a high productivity. Specialists use spot welding more often than other types of welding. The formation of permanent joints of materials occurs as a result of electric heating and deformation during compression. Workers warm up the products with pulses of alternating, direct or unipolar current of industrial frequency 50 Hz. Researchers have registered adverse factors at the welder's workplace that have an impact on health. These are high temperature, splashes and metal vapors, pulsed magnetic fields (PMF) of industrial frequency 50 Hz. The study aims to explore the levels of pulsed magnetic fields of industrial frequency of 50 Hz at workplaces during the operation of contact spot welding installations. The study included the study of the technology of contact spot welding, instrumental measurements and hygienic assessment of the levels of PMF of the industrial frequency of 50 Hz at the welders' workplaces during the operation of equipment in normal mode. Specialists have performed instrumental measurements of PMF levels with a TP2-2U milliteslameter during operation of three models of semi-automatic welding machines based on spot welding installations. The researchers recalculated the measured levels of magnetic field induction to the maximum operating current (Imax) possible during the technological process. Instrumental measurements showed that the magnetic field strength at the welders' workplaces depended on the type of installation, the distance from the radiation source, the localization of exposure, and welding of specific products. Experts registered the highest levels of magnetic fields in the arm area from 1096.0 to 5512.0 A/m. At the maximum operating current, the magnetic field strength can reach 13 678.0-11 024.0 A/m. The study showed that the intensity of pulsed magnetic fields of industrial frequency 50 Hz in the workplace can exceed the maximum permissible levels. To protect workers, it is necessary to limit the time of exposure to magnetic fields. Limitations. The studies are preliminary in nature and have limitations on the scope of the study.