Stepanov D. Arc welding wear-resistant metal using oxide nanopowders.

The thesis is devoted to finding ways to increase the wear resistance and service life of the products, working in conditions of friction of metal on metal and abrasive wear. Developed rational modes mechanochemical processing to obtain homogeneous powder mixtures of nanoparticles and microparticles using a planetary ball mill with an additional evacuation working capacities. Confirmed positive effect on wear resistance volume ratio of aluminum and titanium nanopowders oxides in weld surfacing high chromium compositions with a high content of carbon in which wear resistance is increased by 2 times, but in relation to these compositions more effective is silica dioxide increasing wear resistance by 3 times. The analysis of the morphology and chemical composition of inclusions for conditions of weld surfacing medium alloyed composition shows that in the initial state the core of inclusion contains mainly aluminum silicate manganese but providing of silica dioxide near with it form the inclusion of aluminum oxide (corundum) that in increase of volume fraction is as a solid structure component and this explains more effective influence of nanopowders silicon oxide on wear resistance of weld metal. The technological recommendations that take into account the specific input of nanocomponents into the weld pool and the features of weld surfacing technologies are developed.