Sheet metal products rust and water penetration of the weld how to solve?
Sheet metal processing weld by pickling phosphating after spraying, after a period of time there is always some rust water leakage, this problem before processing, how to solve?
1 pickling cracks without acid neutralization or neutralization is incomplete, phosphating film is not completely rust coating. After a period of rust spilling cracks.
2 strong acid cleaning, alkali degreasing. Residue in cracks are not washed clean and white. The resultant dried coating cracks. For a period of time, the white product. To produce chemical reaction and corrosion in the air and the overflow at the cracks.
This problem occurs in the 3~11 month. The general sports equipment, office furniture manufacturers should pay attention to. This is a non safety period. Should conscientiously do a good job before the treatment of.S
Two, sheet metal processing to prevent the problem of solution:
1 should be used in alkaline degreasing degreasing. Cannot contain protopine components of.TAL should be controlled in 15POINT or.PH can not exceed 13
2 sulfuric acid can be used in pickling. The pickling time can not be too long. It is best to use phosphoric acid.
3 after the pickling is best to 1~2 sodium carbonate neutralization.
4 surface adjustment is best to use oxalic acid, the use of concentration 1~2.
5 zinc series phosphating treatment acidity to take the upper limit. Dipping treatment concentration:.FA:1.2AC:8 above TA:35 (20CC fermentation tube)
6 wash the project do not have to wash clean, washed to maintain overflow.