Classification of black boiling process

The blackening process is divided into normal temperature blackening and traditional high temperature blackening. The advantage of blackening at room temperature is that at room temperature, it can be impregnated into a film through the workpiece, which is more convenient. The disadvantage is that the film is not dense, easy to fall off, and the antirust effect is not good, and its cost is much higher than that of the traditional blackening method. The traditional blackening process is to heat the sodium hydroxide solution and react with the workpiece to form a dense film. The film produced by this process has good curing effect, good surface quality and excellent wear resistance. The disadvantage of this process is that the reaction conditions are harsh, and the reaction solution needs to be heated to boiling, and the reaction time is slightly longer than that of blackening at room temperature.

Black boiling process, the general black boiling process is: decontamination and oil removal-cleaning-pickling and rust removal-cleaning-blackening-cleaning-saponification-oil soaking.

Comparison between blackening process and other surface treatment processes: process type, film color, anti-corrosion effect, equipment put into use, pollution, treatment time, blackening, blue-black and good general mechanical internal parts, springs, fasteners, etc. They are all extremely low, generally, the silvery white of galvanized steel is very low, all kinds of carbon steel workpieces are higher and longer, the self-swimming paint is mostly black, and the workpieces such as extremely high gas springs are generally very long.