Polyurethane Primer Coatings Polyurethol tested in these solutions for 14 months. Coatings Polyurethol containing a hardener retained good adhesion to St3 steel. Coatings Polyurethol without hardener lost adhesion in solutions of potassium chloride, borofoska, diammofoska and nitrophoska. The effect of a borofoska solution on the electrical conductivity (from 1 nA) and resistance (up to 10 GΩ) of Polyurethol and Raptor coatings was studied using the IKS-1 measuring kit. Coatings were applied by spraying and brushing, in one and several coats, with and without hardener. The electrical resistance of a two-layer coating of Polyurethol was 130 MΩ, a single-layer coating was 17 MΩ after a year of atmospheric testing. The electrical resistance of the Raptor coating in three layers with a thickness of 300 microns decreased from 130 to 22 MΩ after 200 days of testing in a solution of borofoska. The insulating power of 1 coat of Polyurethol when applied by spray is equal to the insulating power of 2 coats of Raptor when applied by brush. It has been established that polyurethane coatings Polyurethol and Raptor are suitable for anticorrosion protection of low-carbon steels from the action of mineral fertilizer solutions. The insulating power of 1 coat of Polyurethol when applied by spray is equal to the insulating power of 2 coats of Raptor when applied by brush. It was established that polyurethane coatings Polyurethol and Raptor are suitable for anticorrosion protection of low-carbon steels from the action of mineral fertilizer solutions.

Possible criteria for the effectiveness of inhibitor protection of agricultural machinery and equipment: integral and differential; quantitative, semi-quantitative, qualitative; a generalized quantitative assessment based on the weightiness of each type of destruction; mass, deep, volumetric; technical and economic; environmental and toxicological, etc. were considered. It was noted that each of the criteria taken separately is not always unambiguous in specific conditions, which can lead to a subjective assessment of the appropriateness of using certain corrosion inhibitors (CI). Electrochemical methods for assessing the effectiveness of inhibitor protection are highlighted as promising, which is associated with the desire of researchers to reduce the time of corrosion testing. As an example, a study of the metal-protective coating-electrolyte system by the method of polarization resistance with an assessment of the contribution of each component is considered. Compositions based on trans-former TKp, industrial I-20A, motor M10G2k, fresh and used (MMO), and combined IR CortecVpCI-368 and Cortec VpCI-369 were studied. Coatings on steel were preliminarily formed during the day. Comparison of the results on the protective effectiveness of compositions in I-20A with those also obtained by the method of polarization curves and gravimetric methods in a 0.5 M NaCl solution and in a thermal moisture chamber G-4 showed qualitatively similar results, which indicates the reliability of the results obtained by the method of polarization resistance. The maximum protective efficiency is observed for compositions based on MMO with an IC concentration of 3 -10 wt. % in MMO.

The effectiveness of compositions based on fresh M10G2k and used motor oil (MMO) with the addition of paraffin 1-10 wt. % for the protection of carbon steel was investigated in this work. Preservative compositions were prepared by dissolving paraffin in oils with heating. The protective coating on the metal was formed during the day. Kinematic viscosity was measured by the Brookfield method on a rotational viscometer. Studies have shown that paraffin has a thickening effect. Empirical equations were obtained, which are a special case of the Reynolds-Filonov equation, describing the viscosity-temperature dependences for compositions based on fresh and used engine oil and paraffin with a high reliability of linear approximation in the temperature range of 20 - 60 0C. The resulting equations make it possible to determine the kinematic viscosity of the compositions at various paraffin concentrations in a given temperature range. Electrochemical studies have shown that the introduction of paraffin increases the protective effectiveness of both fresh and used engine oil. The protective effectiveness of compositions based on used engine oil is higher. With an increase in the concentration of paraffin, the protective effectiveness of the compositions increases. The best results were obtained for compositions of 10 wt. % paraffin in MMO. Gravimetric studies confirmed the obtained results. Some discrepancies in the values obtained by gravimetric and electrochemical methods are explained by the different duration of the experiments.

The use of cheap, environmentally friendly natural products is especially important for the anti-corrosion protection of agricultural machinery and equipment. The studies were carried out on samples of carbon steel St3.Coatings from sunflower and rapeseed oils and their sediments; birch tar and its emulsion prepared with a homogenizer; decoctions of bifungin, black and green tea, coffee, oak bark, potato and beet peels, orange and banana peel, bay leaf, onion peel, field honey, sugar, currant berries, dried garlic, tobacco, black and red pepper, seasonings hops-suneli, celandine were studied. Gravimetric studies in a G-4 thermal moisture chamber, in a 0.5 M NaCl solution, in decoctions of natural products were used to assess the protective properties of natural products. in 0.5 M NaCl solution and 5-9% - in thermomoisture chamber G-4. The application of vegetable oils on a wet surface practically does not affect their protective effectiveness, and application on a rusty one (preliminarily oxidized for 1 month) leads to a significant decrease in the protective effectiveness of coatings: by 33 and 42% for sunflower and rapeseed oils, by 23 and 40% for their sludge, respectively. Sediments of vegetable oils completely protect the steel surface when tested in a saline solution for 3 months, in a G-4 thermal moisture chamber for 40 days, and in full-scale bench tests for a year. The tar emulsion protects the steel surface well enough in a saline solution. Ecologically safe decoctions of common natural products, such as bay leaf, black coffee, orange peel, dried garlic, ground black pepper can be recommended for effective protection of carbon steel from atmospheric corrosion for a short period.