SOME RECOMMENDATIONS ON THE USE OF POWDER ALLOYS IN THE RESTORATION OF AGRICULTURAL MACHINERY PARTS BY PLASMA SURFACING AND SPRAYING

Abstract

The practice of using plasma surfacing and spraying in agricultural and mechanical engineering production for the purposes of restoring and strengthening worn parts of agricultural machinery has shown a relatively high efficiency of these processes. To further improve the efficiency of these methods of restoring and strengthening parts, not all the possibilities and reserves have been used, which include reducing consumption and using cheaper working gases; expanding the range of restored parts through the combined use of various powder filler materials. As a result of our research, we found that when feeding surfacing powders into a plasma torch, the best flow properties are possessed by powders having a spherical shape with a granulometric composition of 0.4 ... 0.5 mm. Powders obtained by spraying liquid metal with water or inert gas meet all the requirements of plasma surfacing. The optimal value of aluminum additive for the entire group of studied alloys is sormite + 6 ... 8%; US-25 + 6 ... 7%; Al; FBH-6-2+ 2…3% Al; T-59OP +10…12% Al; PG-L101 +2…3% Al. Testing the efficiency of self-fluxing in comparison with protection in gas environments (Ar; N2; CO2) showed that the quality of the deposited layer of the developed compositions is not inferior to deposition in an argon environment. The hardness of the powder mixtures is HRC 49-53. Wear resistance is up to 5 times higher than the wear resistance of steel 45, hardened to a hardness of HRC 54-56.