Application of anticorrosion technology on slewing bearings

A wind power equipment company requires its wind power equipment on the slewing bearings of anti-corrosion more than 20 years.There are two main antiseptic methods for the slewing ring of wind generator.The other is the technology of spraying zinc with antiseptic coating.This paper mainly studies and analyzes the application of the two anticorrosion methods in the slewing  ring.


Thermal spray aluminum and zinc corrosion resistant coatings

In any environment, Zn and Al can provide long-term and effective anti-corrosion protection for steel products, and this anti-corrosion effect is long and does not need special maintenance.It is important to be anode for steel, zinc and Al itself in the electrolyte Application of anticorrosion technology on slewing bearingscan produce cathodic protection for steel matrix, and even coating of steel body after incomplete or mechanical damage, the cathodic protection can prevent corrosion of steel.Generally, Al corrodes more slowly than Zn under acidic conditions.In alkaline conditions the effect is opposite.
Before the experiment, it is necessary to clean the bearing part of the rotating disk to be sprayed, and it is better to use acetone to remove the pollutants and dirt on its surface, and the parts that do not need spraying should be protected.It is important that the compressed air used in sandblasting should be clean and dry, so as to ensure the quality of the spraying surface [1].As per the procedure, the surface roughness Ra of the substrate after sand blasting should be 10-20m.The surface of the rotor bearing shall be dry and free from sundries, rust residues and oxide skins, and the coating shall be sprayed within four hours.

Spray zinc with antiseptic coating

In the process of sand spraying, zinc spraying and antiseptic coating, it is best to use air spraying or high pressure airless spraying.
When hot-sprayed aluminum, zinc and zinc are added, their corrosion resistance is not much different, but the latter seems to have better comprehensive performance, simpler and more convenient operation.

(1) When the dry film added with zinc contains more than 95% zinc, the purity of zinc particles is almost 100%.This means that it not only has excellent cathodic protection, but also has the same protective barrier as organic coatings, and has good corrosion protection.

Through the empirical formula, the corrosion life can be seen from the formula: n = GK/g;

As can be seen from the formula, n is the durability time.G is the total adhesion amount of zinc layer, among which the coating amount of 1m zinc layer is about 6.98 G/m2.Where g is the amount of corrosion.According to the international standard of ISO12944, this kind of situation should add 0.7 to zinc commonly.

(2) In addition to air and airless spraying, there are other zinc addition methods, such as brush painting and rolling coating.Whether in the workshop or in the field, the zinc can be applied, which is limited by the site very little, and can be done in 510 seconds under normal circumstances, very fast.In addition, zn has a long retention time. Compared with hot spray aluminum and zn, zn has better corrosion resistance.

(3) Zinc can be added even in contact with drinking water. It is free of poison or heavy metal.By contrast, hot spraying of aluminum can cause pollution and harm people.

(4) The construction process of zinc addition is simpler.