How to remove the unqualified phosphate film?
Removal of phosphate film can be carried out by one of the following methods.
① sandblasting of the workpiece.
② workpiece in 10% to l5% hydrochloric acid solution in a strong corrosion at room temperature, or in the heated to 40 to 50 ℃ of sulfuric acid corrosion.
③ in 15% ~ 200, of caustic soda or potassium hydroxide solution, at 80 ~ 90 ℃ to deal with.
④ Note that before removing the phosphate, the workpiece should be pre-greased with any existing method. When retired after the phosphate film, to be washed and neutralized by water can be re-phosphate treatment.