ВОССТАНОВЛЕНИЯ ДЕТАЛЕЙ СЕЛЬСКОХОЗЯЙСТВЕННОЙ ТЕХНИКИ НАНЕСЕНИЕМ КОМПОЗИЦИОННЫХ ПОКРЫТИЙ НА ОСНОВЕ ЖЕЛЕЗА

Abstract

Great opportunities for increasing the resource of parts of agricultural machinery that require restoration are opened up by technologies for applying hardening coatings. Options for obtaining galvanic deposits in various electrolytes, which allow depositing metal coatings with various special properties that ensure reliable operation of restored units under appropriate conditions, are considered in the article. Solutions of sulphate, chloride, and hydroboric fluoride salts of divalent iron were used as the electrolyte. Methods of chemical analysis of galvanic deposits were used. The hardness of the deposited layers was determined using a PMT-3 instrument. The effect of various alloying additives on the quality of the precipitates obtained is analyzed depending on the concentration of inclusions. The boundaries of inclusion concentrations are determined. It has been established that for controlled deposition of a composite coating, the concentration of inclusions in the deposited iron-containing coating should not exceed 20 g/l. It has been found that even an insignificant presence of manganese inclusions in an iron-based composite coating, which is of the order of the measurement error, doubles its hardness. The dependence of the concentration of ammonium chloride, as the base material for the extraction of pure manganese, on the hardness of the deposited galvanic precipitate, was studied in the framework of the described study. The highest hardness was achieved at a concentration of NH4Cl in the range of 100–150 g/l, and manganese - 0.4% by weight. Graphical dependences of the main quality indicators of the resulting coatings on the type and composition of the electrolytes used were obtained. The influence of the electrolyte temperature and electrolysis regimes on the hardness of the deposited metal is analyzed.