Wear of the surface of the coulter of the seeding complex and methods of its strengthening

The article presents the results of studies of abrasive wear at different points of the friction surface of the working element of a seeding machine when moving it in the soil environment. The initial graphs of abrasive wear of the friction surfaces of soil-cultivating parts were preliminarily established by simulating their loading on laboratory stands. The obtained graphs of abrasive wear characterized the friction surfaces within the boundaries of greater or lesser expected intensity of abrasive wear. Taking into account the different wear intensity at different points of the friction surfaces, hardening with gray cast iron was carried out using the electric spark method. Gray cast iron was preliminarily subjected to preliminary heat treatment, consisting of cyclic annealing at temperatures of 500 - 600 ° C with a temperature interval of 50 ° C (one cycle - heating for 1 hour, at specified temperatures and cooling with a furnace). Preliminary stages made it possible to form a wear-resistant layer in several passes, while the structure of the cast iron and the base metal did not undergo changes. The physical and mechanical properties and structure of the hardened layer, which included gray cast iron, were studied. The tensile strength of gray cast iron after heat treatment reached 125…140 MPa. The hardness of the deposited layer was higher (4600…5100 MPa) than that of the base metal (2200…2300 MPa). Based on the results of product testing, heat-treated gray cast iron can be recommended for use as a hardening material in differentiated surfacing on the surface of seed drill coulters and cultivator blades. Keywords: SEEDING COMPLEX, COULDER, ABRASIVE WEAR, WEAR-RESISTANT COATING, ELECTRIC SPARK SURFACING