Powder coating
Powder coating is a surface treatment where a dry plastic powder is electrostatically applied to the workpiece and cured by heat. This improves the protective layer and gives the material a smooth finish.
Physical-Chemical Mechanism of Action
A dry powder coating is produced in powder form and applied to the workpiece surface by electrostatic spraying. The electric charge ensures the powder is evenly distributed over the surface. After application, the coating is cured by a heat source and bonds to the metal.
Metallurgical Relevance & Welding Risks
Powder coating increases the corrosion resistance of the material and improves its surface quality. However, a coating that is too thick can make welding difficult, as it acts as a barrier layer and prevents access to the metal. A missing or incomplete coating can lead to corrosion and the formation of defects.
Workshop Practice & Instructions
Before welding, the coating must be carefully removed. This is done by mechanical or chemical removal methods. The temperature and time of the heat treatment process must be precisely controlled to ensure a uniform coating. A missing coating layer can be restored by additional coating cycles.