Painting on stainless steel surface
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Stainless steel has good corrosion resistance, but recently I’ve often heard that some foreign customers request that the surface of stainless steel containers also be coated, which surprises me. I would like to know: 1. The advantages of painting on stainless steel surfaces, and in what situations is it necessary to do this? 2. How to improve the paint adhesion on stainless steel – is it possible to apply paint to it? And how should it be applied? ---According to the information I found, the shiny surface is first sprayed with glass beads to create a rough texture, and then primer and topcoat are applied. Are there any other things to keep in mind?
Stainless steel does not rust completely. It’s just that the rate of rusting is slower, and painting can effectively slow down external corrosion
There is stainless steel painting, and valves also come with such painting; some are treated through pickling and passivation, all of which serve to slow down the rate of corrosion.
Thank you! I found another post on stainless steel surface treatment: http://bbs.hcbbs.com/thread-455303-1-1.html
http://jingyan.baidu.com/article/380abd0a5ccf2d1d90192c13.html For more details, please visit that webpage. Stainless steel equipment usually requires only shot blasting and polishing; it is rare to see its outer surface painted~~
Most of these are related to the operating conditions of the equipment and the atmospheric environment. For example, in coastal areas, the high concentration of chloride ions can easily accumulate beneath the insulation layer; especially when the temperature of pipelines or equipment exceeds 60 degrees, there is a risk of stress corrosion cracking. Painting the surface of stainless steel is a common practice, and the quality of this painting depends mainly on the quality of the paint itself and the standard of application.
By chance, I saw today that a certain company specified painting the outer surfaces of stainless steel and duplex steel pipelines. Note: Painting of stainless steel piping systems is done to eliminate pitting caused by grinding of carbon steel and welding spatter that deposits on the pipes, as well as to reduce the risk of chloride stress corrosion cracking at high temperatures.
The surface of stainless steel is relatively smooth, so paint generally has poor adhesion to it. Nowadays, an epoxy zinc yellow primer is used, followed by a topcoat chosen according to your requirements. A fluorocarbon primer combined with a fluorocarbon topcoat can also be used for corrosion protection, although the cost is higher.
Yes, the main concern is chloride stress corrosion caused by the environment. On offshore oil platforms, the outer surfaces of many stainless steel components need to be painted. Of course, the surface is first treated with sandblasting to achieve a certain level of roughness, thereby improving the adhesion of the paint; special sand designed for stainless steel is used for this purpose.