RESEARCH ON LASER HARDENING OF AUTOMOTIVE PARTS IN THE AGRICULTURAL INDUSTRY

During laser hardening of various automobile parts, an important factor influencing their service life is the depth of hardening and microhardness, which depend on the parameters of surface laser treatment. Successful selection of the parameters of the laser hardening process, the use of laser alloying can provide a significant increase in the operational characteristics of the processed automotive parts in the agricultural and industrial complex. The aim of the work was to determine the dependence of the depth and microhardness of the surface zones of the studied samples of iron-carbon alloys on such laser treatment parameters as laser radiation power, processing speed and the use of their laser alloying using strengthening impurities of boron carbide and tungsten carbide in an absorbing coating. As a result of the research, it was found that with an increase in laser treatment power, the microhardness in the hardening zone increases slightly. Only at P = 1.5 kW and v = 25 mm/s does surface melting occur, and hardening without melting is observed to a depth of up to 0.5 mm. The microhardness of martensite in the lower layers of the HAZ of steel 35 increases continuously with increasing processing speed. In the upper layers of the HAZ, up to a processing speed of more than 40 mm/s, the microhardness also increases to 6900 MPa, and with a further increase in speed, it decreases. The results of the study of the influence of strengthening impurities of boron carbide and tungsten carbide in the absorbing coating (yellow gouache) showed that the highest microhardness of the surface zones of the processed samples can be achieved by using a tungsten carbide impurity at a processing speed of V=1 mm/s. It was established that the iron-carbon alloys used by domestic manufacturers of motor vehicles can be effectively subjected to laser processing, which will allow to provide a significant increase in the operational characteristics of the corresponding parts.