WARNING RESISTANCE OF CULTIVATOR PAWS MODIFIED BY NITROGENATION IN GLOW DISCHARGE

To increase the wear resistance of the tillage tool-paws of the Tiger-Mate 200 cultivator, the technology of anhydrous nitriding in the glow discharge (BATR) of the paws has been developed. As a result of the analysis of the obtained dependences for further research to strengthen the working surface of the cultivator paws, the modification process was carried out in a mode that provides high enough plastic properties of the modified layer to eliminate chipping and chipping of the cultivator paws and blunting during operation, layer: medium – 25% N2 + 75% Ar; nitriding temperature – 520°C; pressure in the discharge chamber – 200 Pa; duration of nitriding – 6 hours. As a result of applying this method of modification, a surface layer with a thickness of 120...150 μm with a microhardness of H100 950…980 MPa based on an elastic base (hardened steel 35G after low-temperature tempering obtained in the process of nitriding H100 500…600 MPa) was obtained. Unmodified and modified paws were installed and tested on the cultivator of the Tiger-Mate 200 model in production conditions in the fields of STzOV “Garant” (Khmelnytsky region, Ukraine). In the course of tests change of the sizes of paws in process of their attrition was fixed. The test results confirmed the increase in wear resistance of the modified paws in comparison with the unmodified ones by 1.7 ... 1.8 times.