Fosfaatointikäsittelyt

Fosfaatointikäsittelyt, commonly known as phosphating in English, are a surface treatment process primarily used for metals. The goal of phosphating is to improve the corrosion resistance of the metal and to provide a better surface for subsequent treatments like painting or powder coating. It is a chemical conversion coating process where the metal surface reacts with a phosphoric acid solution containing metal phosphates.

The most common types of phosphating are zinc phosphating, iron phosphating, and manganese phosphating. Zinc phosphating is widely used for steel and is known for its excellent adhesion properties, making it a good base for paint. Iron phosphating is a simpler and faster process, often used for less demanding applications or as a pre-treatment for painting where high corrosion resistance is not the primary concern. Manganese phosphating is particularly effective in providing lubrication and wear resistance, making it suitable for components like engine parts and fasteners that experience friction.

The phosphating process typically involves cleaning the metal surface to remove oil, grease, and other contaminants, followed by the phosphating bath itself. After immersion or spraying, the metal is rinsed and often treated with a passivating agent to seal the coating and enhance its protective properties. The resulting phosphate layer is crystalline and adherent to the metal substrate. This layer is porous, which helps in the adhesion of organic coatings applied afterward. Fosfaatointikäsittelyt are a crucial step in many manufacturing processes, contributing significantly to the durability and performance of metal products.