Surface Treatment of Hot-Rolled Stainless Steel Plates
Hot-rolled stainless steel plates are one of the most commonly used building materials. Although stainless steel plates exhibit strong corrosion resistance, their surface treatment is still necessary before being used in construction projects. This article will discuss the various techniques used to effectively treat the surface of hot-rolled stainless steel plates.
The first step to treating the surface of hot-rolled stainless steel plates is to clean them. This involves using various cleaning solutions such as alkaline cleaners, hydrochloric acid, or caustic solutions to rid the plates of dirt, oil, grease, or other contaminants. It is important to remove contaminants and degrease the plate in order to ensure that any coatings applied to the plate will bond properly. Once the plate is clean, it can then be de-scaled, which involves using a sandblaster, fiberglass brushes, or steel wool to remove any rust or scale that may have formed during the hot-rolling process.
Once the plate is clean and free of surface contaminants, it can be treated with chemical solutions to improve its corrosion resistance. An example of such a treatment is pickling and passivation. In this process, the stainless steel plate is immersed in either hydrochloric acid or nitric acid, depending on the grade of stainless steel. This process removes any free iron particles from the surface and forms an oxide layer, which is more corrosion-resistant than the untreated plate.
The nitric acid also forms a thin film of chromium nitride, which further increases corrosion-resistance of the plate. Once the plate has been pickled, it is then passivated with a citric or sulfuric acid solution, which serves to seal the corrosion-resistant layer and protects the plate from further oxidation.
The surface of hot-rolled stainless steel plates can also be improved through electroplating. This involves coating the plate with a layer of another metal, such as nickel or silver, which is more corrosion-resistant than the untreated plate. The electroplating process is often followed by a passivation process to seal the plating layer.
Finally, hot-rolled stainless steel plates can be treated using organic coatings. These coatings help to reduce the surface energy of the plate, making it less prone to corrosion, and may also help to improve the aesthetics of the plate. Common examples of organic coatings used on stainless steel plates include polyurethane, polyvinyl chloride, and epoxy resin.
In conclusion, there are many techniques used to treat the surface of hot-rolled stainless steel plates. Cleaning, de-scaling, pickling, and passivation all serve to improve the corrosion-resistance of the plate, while electroplating and organic coatings provide further corrosion resistance and improved aesthetics. The choice of method will depend on the desired end result and the specific grade of stainless steel being used.
