Recipe:
Nitric acid: the mass fraction of 10%
Ammonium bifluoride: the mass fraction of 0.3%
Sodium hydroxide: the mass fraction of 3%
Preparation method: nitrate water for industrial nitric acid diluted in accordance with the volume ratio of 1:10; then add ammonium bifluoride, in accordance with the solutionconcentration of 0.3% of the amount to join. Sodium hydroxide with the preparation of the mass fraction of 3% (ie 97 g of water by adding 3 g of sodium hydroxide).
Temperature control: the mixture of nitric acid and hydrogen fluoride, ammonium Temperature Control: 10 ~ 50 ° C; sodium hydroxide temperature control: 70 ~ 80 ° C
Pickling time: 5 ~ 15 minutes, depending on the temperature determines the degree of pickling time.
The pickling process: degreasing - rinse - pickling - and - rinse - dry
Operating method: First of all poured into a mixed solution of nitric acid and ammonium bifluoride to remove the greasy tube 5 to 15 minutes after the pour solution; with hot
sodium hydroxide poured into the tube and water to rinse the tube; blowing with compressed air dry.