The process of flow-through electrochemical chrome plating of the inner surface of the cylinders of a deep rod pump (DRP) is considered. As a result of the analysis, a low-concentration electrolyte was developed and selected without the use of additives. The components of this electrolyte are chromium anhydride CrO3 and sulfuric acid H2SO4. When applying coatings, an insoluble lead anode is used. The electrolyte solution is heated to a temperature of 60…65 °C. A medium-density current is used. The features of chrome plating of the inner surfaces of DRP cylinders are presented, namely, carrying out the process on a special chrome plating plant, depending on the size and length of the parts, the rate of supply of the electrolyte solution and its temperature are selected in order to evenly deposit chromium along the entire length of the cylinder. A distinctive feature of the installation is the method of forced feeding of a heated solution into the space between the surfaces of the processed product with an anode coaxially mounted in relation to it. In this case, the coating is applied when the anode is reciprocated and the product is rotated at the rate of flow of the electrolyte solution. During the experiment, studies were conducted on the selection of modes for applying a hard chromium corrosion-resistant coating to the inner surface of the DRP cylinder. As a result, the optimal ratio of chromium anhydride and sulfuric acid in an aqueous electrolyte solution was found, which was 100:5, and optimal coating modes were worked out. Chrome coatings obtained using the developed low-concentration electrolyte and the chrome plating method have increased hardness up to 25% and reduced porosity by 50 times or more after honing; at the same time, shiny solid low-porous sediments are formed-layers that meet the requirements of corrosion resistance and wear resistance of coatings.

EDN IHACJU