What is the difference between Electropolishing Stainless Steel and Passivating Stainless Steel?
Passivation is the treatment of stainless steel in a nitric acid or citric acid solution to remove iron contamination on the surface. The contamination is from fabrication such as stamping, drilling, machining, welding, cutting, forming or wire brushing. Passivation does not change the appearance of the stainless. If the stainless has been heat treated or welded, the resultant scale or discoloration must be removed by either abrasive methods or by pickling. The processor must know the alloy of stainless steel before passivation is attempted so that the proper solution will be used. Electropolishing is the reverse of plating in that metal is removed from the surface rather than deposited. Electropolishing is primarily used to obtain a bright, clean, appealing surface. Electropolishing also removes burrs and sharp edges; eliminates hydrogen embrittlement and removes stress from springs and stampings by removing microscopic nicks and scratches from the surface. Because high points on the
