BY-918 cold drawn steel tube coated phosphating - saponification coating treatment process
First, the process
Hydrochloric acid descaling
High pressure water rinse
Flowing water soaking
Saponification lubrication treatment
Transfer from cold to cold drawing
Second, the hydrochloric acid pickling solution
Industrial grade hydrochloric acid (31~33%) 60~80%
Hydrochloric acid mist inhibitor
Third, the preparation of phosphating solution
1. BY-918 phosphating solution consists of three kinds of tank liquid (also called opening agent), replenishing liquid and BY-131 accelerator.
BY-918 with bath solution 180 kg / m 3
BY-131 accelerator 1~2 kg/m3
For example: (taking 1m3 phosphating working solution as an example)
1 Add a tank solution in the tank (must be clear, can not be a replenishing liquid) 180 kg, add water to 1m3.
2 accelerator is preferably added about half an hour before phosphating
Phosphating solution liquid is preferably heated with cold water and then heated
The phosphating working solution is preferably heated slowly and then worked. If it can be heated to 60~70 °C in advance, it will be naturally cooled after holding for a period of time. The next day, it will be heated to 60~70 °C to process the workpiece better.
It is best to add the accelerator once before each phosphating, and the addition amount is 0.5-1 liter/m3 (it is best to double the phosphating solution when it is used for the first time)
The process parameters of BY-918 phosphating working fluid are:
Free acidity: 5~6 points
Total acidity: 50~60 points
Acid ratio: 9~12 (total acidity/free acidity)
Phosphating temperature: 60~70°C
Phosphating time: 20~30 minutes
3, turn the cylinder
During the phosphating process, sediment will be produced. After continuous use for a period of time, the bottom mud will accumulate more. At this time, the upper layer of liquid should be extracted and the lower sludge should be exhausted. After the end of the tumbling, the supernatant liquid is returned to the phosphating tank, and the phosphating working fluid is lost more. The volume of the phosphating solution (m3) which should be roughly lost shall be measured according to the method of Note 2, and the required amount of the tank solution may be added to the level of 180 kg/m3 to return to the level before the slag. This work is considered part of the distribution. The liquid to be added must be a tank. If a mistake is used and the supplement is used, the phosphating solution may malfunction or even malfunction.
Fourth, the preparation and use of BY-7760 lubricant
BY-7760 lubricant 60 kg/m3
Water balance / m3
For example: to prepare a 1m3 lubricant, add about 60 kg of lubricant in cold water, stir and disperse evenly.
2, the use temperature: 60 ~ 70 ° C
Processing time: 5~10 minutes