SU1244216A1 - Method of cleaning metal parts - Google Patents

Description

one

The invention relates to the electrochemical cleaning of metal lei, mainly agricultural machines, and may find application in cleaning repaired metal parts of agricultural machines from carbon deposits and other contaminants.

The aim of the invention is to increase the speed and quality of cleaning.

The cleaning is carried out by anodic treatment in the electrolyte in the mode of microarc or arc discharges at a current density of 1-50 A / dm and a voltage of 100-350 V.

As an electrolyte, detergent solutions can be used that allow the process to be conducted in the mode of microarc or arc discharges. The anode current density and voltage are chosen within the specified limits depending on the amount of contamination on the surface of the part and the degree of contamination.

Example 1. Electrolytic cleaning of the steel parts of the hub-roller chains of the machine was carried out in a known manner for the application of the 1RMG-4 mineral fertilizer. In the cleaning process, an electrolyte of the following composition was used, g / l: caustic soda 20; soda ash 12; trisodium phosphate 12; liquid glass 3. Parts were cleaned at an electrolyte temperature of 80-90 ° C, a voltage of 12 V and a current density of 5 A / dm

During the cleaning process, oil soils, tar deposits and paint on rollers, plates and open surfaces of the sleeves are removed completely within 28-30 minutes. The inner surfaces of the sleeves for the same time were cleaned only by 30%, mainly in the areas located near the ends of the sleeves. In order to effectively clean the inner surfaces of the bushings, it is necessary to use additional internal anodes, which complicates the design. Corrosion Products those caused by the impact on the parts of mineral fertilizers during the operation, are not destroyed: The corrosion products are not cleaned in a known manner even at a current density of 25 A / dm and a holding time of 1 hour.

Example 2. Electrolytic cleaning of steel parts of the roller-roller chains of the .1RMG-4 machine was performed by the proposed method.

sixteen

Purification was carried out in the anode microplate mode at room temperature of the electrolyte, voltage 250 V. and current density of 5 A / dm in the electrolyte of the following composition, wt.%: Sodium hexamete-phosphate 5; glycerin 3, water the rest.

During the cleaning process, oil soils, tar deposits and paint on the inner and outer surfaces of the parts (rollers, plates and bushings) are completely removed in 30-35 seconds. Full cleaning of surfaces from corrosion products in this mode occurs after a retention within 1.5-2.0 minutes. At the same time, the surface of the parts acquires a silvery-matt shade and does not have contamination products both on the external and internal areas.

Thus, the presented data shows that the previous method (compared to the known method allows to increase the cleaning speed by more than 50 times, to improve the quality of the cleaning process of parts of complex configuration, as well as parts with strong contamination. The proposed cleaning method can be combined followed by a protective coating process, which is achieved by using appropriate electrolytes.

Example 3. Electrolytic cleaning was carried out from corrosive destruction products of the body parts of pumps UN 41000 for chemical plant protection machines - sprayers made of aluminum alloys, with simultaneous application of a protective coating. The process was carried out in the anodic microarc mode at a voltage of 200-350 V and a constant current density of 7 A / dm in the electrolyte of the following composition, wt.% Sodium hydroxide 2; glycerin 3; sodium silicate 30; water the rest. In addition, fine (1-3) μm alumina powder was introduced into the electrolyte solution; it was modified in an amount of 50 g / l.

In the course of processing, a composite aluminosilicate coating was obtained, having (according to the data of metallographic analysis) the following indicators: a coating thickness of 0.01–0.03 mm, Po312D42164

Resistance of coating 5-6%, coupling c. The coating showed a high resistant base good, the microhardness of the coating in the media of pre-chemicals, to withstand 603-766 kg / mm. Without cutting 720 immersion cycles,

Claims (1)

METHOD FOR CLEANING METAL PARTS, including electrochemical treatment in an electrolyte at a current density of 1-50, characterized in that, in order to increase the speed and quality of cleaning, anode treatment is carried out in the mode of microarc or arc discharges at a voltage of 100-350 V. N3