The method of using acid solution to remove oxide scale and rust on the surface of steel is called pickling. Acids for pickling include sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid and mixed acids. The pickling process is to remove the surface oxide scale, and then go through lubrication treatment (carbon steel-phosphorous saponification, stainless steel-butter lime, copper and aluminum pipe-oiling, using the old process-copper plating), and then deep drawing processing. If the steel pipe is not pickled, there may be oxides and oil stains on the surface, and probably the phosphating solution cannot be able to remove them and the quality of phosphating will be reduced. In addition, in the manufacturing process of steel pipes, after many processes, if you are not careful, scars will appear on the surface of the steel pipes, which will reduce the corrosion resistance of the parts and affect the service life. In order to improve the corrosion resistance of the steel...
