The Use of Surfacing Materials to Increase the Durability of Disc Harrow Working Elements

Abstract

Introduction. For surface tillage operation there widely used disc harrows, working bodies of which are discs wearing out during operation. The wear intensity of discs depends on the wear resistance of their working surfaces, working modes and properties of the cultivated soil. It has been found that an effective way to increase the life of discs is surfacing them with wear-resistant materials. The aim of the work is to study the wear out of surfacing materials, which can be used to harden discs and to make recommendation for the use of these materials in the repair departments of agricultural enterprises. Materials and Methods. Surfacing with electrodes T-590 and powder wires PP-Np200Kh15S1GRT, VELTEK-N560.02 and PP-Np280Kh9F7SG4 were taken as test materials. For wear tests of materials in abrasive mass, there was used an apparatus to simulate the moisture content and composition (sandy loam or loam) of the soil. In the disk-pad tests, the effect of abrasive particle size, load and sliding friction velocity on the wear of the materials was studied. In field tests, wear of the disks made of 65G steel, surfaced toothed and solid disks were monitored. Results. Laboratory studies of the materials revealed the effect of soil moisture and composition, load, abrasive grit and sliding friction velocity on wear. The main factor determining the wear resistance of materials is their structural state. The indexes of wear resistance of surfacing were determined during the laboratory tests and confirmed by field tests. Discussion and Conclusion. Surfacing with flux-cored wire PP-Np280Kh9F7SG4 has the highest wear resistance of the studied materials. The technology of hard-facing disks with modern materials, in particular with flux-cored wire PP-Np280Kh9F7SG4, can be implemented in repair departments of agricultural enterprises when they have the equipment for hard-facing and sharpening of working surfaces.