The basic features of calculating the reliability of agricultural machinery are shown, in contrast to industries such as mechanical engineering, radio and television equipment, automation systems and etc., in which machines and apparatus operate in steady modes, while agricultural machines do in difficult soil and climatic and dynamic conditions.
Еconomic aspect of reliability is substantiated and patterns of change in the efficiency of use of agricultural machinery in time are established, the economic parameters of reliability are determined. With the help of the theory of similarity and dimensions as well as the planning of multifactor experiments, through the original installation manufactured by us, the basic physical and mechanical properties of metal coatings are studied, obtained by welding under flux, there are relevant similarity criteria determined that characterize the process of restoration of worn parts and, after processing of experimental data an analytical view of criterion equation is formed and rational modes of the restoration of parts under submerged arc welding are set. Further, to optimize the process, the scheduling theory of extreme experiments has been used and as factors in the regression equation there have been chosen most significant similarity criteria. In methodics elaborated by us, it was obtained an adequate equation and by a method of steep ascent (movement along the gradient), there were determined optimal modes of recovery for metal coatings with high physical and mechanical properties (hardness, wear resistance).
Under these regimes there were recovered worn ploughshares and their operational check showed an increase of resource as many as 1.4…1.5 times. For surfacing worn parts with complex configurations (ploughshare plows, cultivators paws), we have manufactured a special copier allowing to recover the items automatically, in a continuous mode. The feasibility study of the developed resource-saving innovative technology has shown that the restoration of 800 ploughshares provides an yearly economic effect of EURO 1,462.