Application of oil resistant coating on hydraulic oil tank
Application of oil resistant coating on hydraulic oil tank
May 25, 2004
1 Introduction
with the continuous development of mechanical, electrical and hydraulic integration technology, the traditional chain and gear transmission are replaced by hydraulic transmission, and the use of hydraulic components puts forward higher requirements for hydraulic oil. In addition to qualified hydraulic oil, the pressure system should also eliminate various factors that may cause secondary pollution. The anti-corrosion problem of hydraulic oil tank is one of the most important factors among many factors. In recent years, the author has tried to prevent the corrosion of hydraulic oil tank by means of phosphating, antirust oil, electroplating, coating, etc. of stainless steel, and the model with the largest selection of 5 tons. The results show that it is economical and reliable to use coating for anti-corrosion. In this paper, ro - 1 oil resistant coating is used to prevent corrosion of hydraulic oil tank
the anti-corrosion problem of hydraulic oil tank has always been a difficult problem in the coating of construction machinery, and its treatment methods are also diverse, including electroplating, phosphating treatment, direct injection of hydraulic oil without coating, painting on the inner wall of oil tank and the use of stainless steel. The above-mentioned treatment methods, phosphating and direct injection of hydraulic oil are worth studying. From the perspective of corrosion prevention, phosphating treatment is only an intermediate process. Its role is to prevent rust between processes, and to enhance the adhesion of the coating. It cannot be used as the final process of corrosion prevention. However, the direct injection of hydraulic oil has no anti-corrosion effect at all. Generally, No. 10 machine oil applied to No. 45 steel will rust in a damp heat box (temperature 45 ℃, relative humidity ≥ 95%) within a few hours. The two main factors causing corrosion are water, which can maintain its excellent performance and oxygen for a long time. Oil can not effectively prevent corrosion. In recent years, some tube holes and corners cannot be electroplated because of the shielding effect of electroplating during the treatment. The cost of using stainless steel as hydraulic oil tank is too high, which is 5 ~ 6 times the cost of general materials
ro - 1 oil resistant coating is a two-component coating consisting of isocyanate prepolymer as component A and hydroxyl polyester, pigments and fillers, additives and solvents. It has excellent oil resistance, corrosion resistance and damp heat resistance. It is used for the surface protection of workpieces, equipment, oil tanks and oil tanks in contact with oil media. After continuous immersion in gear oil and hydraulic oil at 120 ℃ for 1344 hours, the paint film does not fall off, crack or rust
in order to simulate the actual working conditions of oil resistant coating in hydraulic oil tank, four small oil boxes were made and tested by different pretreatment methods and different matching methods of bottom layer and top coat. Inject hydraulic oil into the oil tank, and then put it into the electric heating oven. Bake it continuously at 80 ~ 120 ℃ for 36 days, and no abnormality is found in the paint film. Then put the oil box in a wet bath (relative humidity 68% ~ 88%, temperature 18 ~ 26
℃) to assess its humidity and heat resistance. After 15 days of storage, observe that the surface of the paint film is still normal. Finally, the four oil boxes were buried in the wet soil for a month. After taking them out, it was observed that no oil box coated with ro - 1 oil resistant paint was rusted. Through the above simulation test, a small batch of trial was started, and the follow-up examination was carried out. The oil tank was opened on the construction site for observation. The paint film of the part brushed with ro-1 oil resistant paint was intact, and a small amount of rust spots had appeared on the electroplated part, so ro-1 oil resistant paint was completely applicable to the corrosion prevention of the inner wall of hydraulic oil tank
coating quality, coating construction and management are the three elements to obtain high-performance coatings. A good coating needs scientific construction and management to achieve the desired purpose. Ro - 1 oil resistant coating is no exception, especially pay attention to the quality of pretreatment before coating, so as to lay a good foundation for coating construction. After a large number of tests, the quality of ro - 1 oil resistant coating can obtain satisfactory results according to the following process
(1) pretreatment chemical pretreatment process: degreasing → derusting → water cleaning → neutralization → water cleaning → phosphating → hot water washing → hot air drying → cleaning foreign matters → painting primer. If manual, tool or shot blasting is used for rust removal, the rust removal grade shall reach ST3 or SA2 specified in gb8923 - 88 5. The primer shall be applied within 8 hours after treatment. In case of overcast rain and high air humidity, the first primer shall be applied within 4 hours
(2) coating construction ro-1 oil resistant paint is a self drying paint. After baking at medium temperature, the hardness and adhesion of the paint film are better than natural drying. Therefore, in the coating construction, polyester ro-1 matching primer, two-component epoxy primer and h06-33 iron red epoxy primer can be used as the matching primer of ro-1 oil resistant paint. After testing, Two component epoxy primer and H06 - 33 iron red epoxy primer have slightly better adhesion. The construction viscosity is adjusted to 35 ~ 45 s (apply 4 cups). Ro-1 oil resistant paint is used as the finishing coat. Before construction, it is configured according to component A: component B 1:
2. The construction viscosity is 30 ~ 40 s (coated with 4 cups). After preparation, it is allowed to stand for 10 ~ 15 minutes before construction. Before construction, the threaded joints in the box are protected with calcium base grease. The construction process is as follows: painting primer → drying → grinding → cleaning foreign matters → painting finish → drying → protection → assembly
(3) precautions operate in strict accordance with the process specifications, and the pretreatment must meet the specified rust removal grade standard. The primer and finish coats are not easy to be too thick, and the thickness of primer coat is controlled within 35 ~ 45 μ M, the thickness of finish paint shall be controlled within 30 ~ 40 μ m 。 The primer and finishing coat shall be painted by brush, and the treated oil tank shall not be welded
LINK
Copyright © 2011 JIN SHI