It is generally preferred that the electrical enclosures are manufactured from stainless steel material. Stainless steel enclosures are used in various industrial applications where corrosion resistance is important. However, there are rules to be considered when selecting and using stainless steel materials.
Stainless Steel Enclosures
Stainless steel is a proven it’s reliability in various industrial applications as electrical equipment enclosures. In the corrosion resistance of the stainless steel, the environment and its conditions of the application, the grade of steel and the surface treatment have determinant importance. When the characteristics of stainless steel enclosures are determined for using in a project, by careful consideration of the factors stated here, the required level of corrosion protection and the overall success of the application can be possible.
Stainless steel self-repair feature
The metallic satin finish of the stainless steel makes itself passive, if a suitable environment is provided, i.e. sufficient oxygen and available rich chromium oxidation. This reaction occurs spontaneously in very short time once the sufficient oxygen contacts on the surface, and the protective layer thus formed becomes thick over time. The resistance against corrosion on the surface has the ability to repair itself in case of mechanical defection.
Environment and its conditions;
The climate of the area where the application will be, has a great effect on the corrosion resistance of the stainless steel material. For example, 304 grade stainless steel is resistant to corrosion under a wide range of environment conditions and climate effects, but it is inevitable to experience corrosion in salt and other chloride environments. De facto, 304 grade stainless steel should not be used up to 10 km inside by the sea coast; but the actual length of this distance can be determined by evaluating the climatic conditions according to the application area specifications. By this reason, it is not recommended to use 304 grade stainless steel in marine applications without taking special precautions. In cold climate zones, chlorides are used as defrosting chemicals and also, can cause point corrosion on 304 stainless steel surfaces.
In industrial environments, chlorides can be existing in smoke and flying ashes. These are dirt and debris deposits on non-washed, uncleaned surfaces and eventually they may cause point corrosion. Even if the right stainless steel is chosen, corrosive substances condensed in the accumulation of impurities in that way, may cause the protective passive layer on the stainless steel surface to be pierced. In such cases, cleaning is necessary. By this way, self-repairing of stainless steel material can be provided and the stainless steel surfaces can be prevented from condensation of sulfur-dioxide, chloride or ferrous deposits. In another particular attention should be paid not only to the general climatic conditions, but also to the specific micro-climatic conditions where the enclosure is to be mounted. The most obvious example to this, is the negative effect in the settlement areas especially in highways, where salt and chemicals are is used as de-icing, which can be carried up to a distance by the vehicles. Likewise, the effects of increased exhaust gas emission by the dense and stopped traffic on the underpass, in the tunnel or at the ticket office, can be evaluated in terms of attracting attention to the micro-climatic conditions.