Martynenko O. Recovery of parts of agricultural machinery by using electro -spark treatment.

The research studies the processes of deterioration, restoration and strengthening of agricultural machinery parts, using the method of electric spark machining (ESM). The research is aimed at developing parameters and materials for restoration of parts and at improving equipment units for the ESM. The method of research and the outfit: fault detection in worn parts, together with the methods of optical and electron microscopy, roentgen and spectrum analysis, corrosion, heat and wear resistance testing. Theoretical results: - optimum restoration parameters were obtained as well as a mathematical model that the influence of the main machining parameters and of the contents of anode components on the quality of the increased layer, which is obtained through calculations and is proved by experiments. Practical results - strengthening and restoration of parts with the ESM method increases in 1,6 times wear resistance during operation. The novelty of the innovations - a calculation schedule of irregularitie s formation at ESM is offered, mathematical relations for the restored layer roughness calculation are adduced. The relation of influence of the spark discharge current on the diameter of a single lune and the formed roughness is detected. A complex researches evaluates the kinetics of the chemical composition change of the layer in time while escalating with electrodes of different alloys. The influence of main parameters of the preceding laser heat treatment on the decomposition of the surface azotized part layer is estimated for the part which is subject to restoration by the ESM method. The degree of implementation - a technological process has been developed, and a customer has accepted the technological task (TLT) to project a specialized site of strengthening and restoration of parts with the electric spark method, the annual actual economic effect being 139540hr. The domain of use comprises part - manufacturing and part - repairing companies.