If rusted bearings and parts are found in the bearing warehouse, they should be treated with rust removal after oil removal and cleaning. The common rust removal methods are mechanical and chemical rust removal.
Mechanical derusting
Commonly used 000 size sandpaper or No. 1, No. 0, No. 00 fine gauze, hand grinding. When grinding, the direction should be the same and the force should be uniform. It can also be used to remove rust with abrasive paste. The commonly used formula of abrasive paste is shown in Table 1-1.
Table 1-1 Formula of Abrasive Paste for Rust Removal
|
Component name |
Content(mass fraction,%) |
||
|
Coarse grinding paste |
Medium grinding paste |
Fine grinding paste |
|
|
CrCl3(Cr2O3) |
81 |
76 |
74 |
|
Na2O3Si(Silicon Rubber) |
2 |
2 |
1.8 |
|
Stearin |
10 |
10 |
10 |
|
Lard |
5 |
10 |
10 |
|
Oleic Acid |
- |
- |
2 |
|
NaHCO₃(Soda) |
- |
- |
0.2 |
|
Kerosene |
2 |
2 |
2 |
Chemical derusting
Chemical rust removal is the use of chemical action to remove the corrosion of bearings. Its rust removal process is: unsealing cleaning and degreasing hot water flushing flowing cold water flushing chemical rust removal flowing cold water flushing neutralization flowing water flushing passivation drying oil seal.
The formulation and working specifications of the rust remover are shown in Table 1-2.
Table 1-2 Formulation and Working Specification of Rust Removal Solution
|
Component |
1 |
2 |
3 |
4 |
|
Cr2O3 (Industrial Use, mass fraction,%) |
15 |
15 |
15 |
15 |
|
H3PO4(Industrial Use, mass fraction,%) |
8-8.5 |
8.5 |
15-17 |
15-25 |
|
H2SO4(Industrial Use, mass fraction,%) |
|
1-1.2 |
1-1.2 |
|
|
Distilled water (or clean tap water) |
76-76.5 |
75.3-75.5 |
66.8-69 |
60-70 |
|
Temperature/℃ |
85-95 |
85-95 |
85-95 |
85-95 |
|
Time/h |
0.4-1 |
0.5-1 |
0.5-1 |
0.5-1 |
