This method is applicable to the determination of the anti-corrosion performance of grease in tapered roller bearings stored in humid conditions. This method is based on the CRC technical document L41, which can show the correspondence between laboratory results and the use results of aircraft wheel bearings lubricated with grease. GB/T 5018-1985 Test method for anti-corrosion performance of grease GB/T5018-1985 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Test method for corrosion preventive properties of lubricating greases
Standard test method for
corrosion preventive properties of lubricating greases
UDC 621.892
GB/T 5018--85
This method is applicable to the determination of the corrosion preventive properties of greases in tapered roller bearings coated with grease stored under humid conditions. This method is based on the CRC technical document L41, which can show the correspondence between laboratory results and the results of use of aircraft wheel bearings lubricated with grease.
1 Summary of the method
This method is to run a new bearing coated with a specimen under a light thrust load for 60 seconds to distribute the grease as in use. The bearing is stored at 52±1℃ and 100% relative humidity for 48 hours. Then clean and check the outer ring raceway of the bearing for signs of corrosion. In this method, corrosion refers to any surface damage (including pitting, etching, rust, etc.) or black stains on the outer ring raceway of the bearing. 2 Instruments and Materials
2.1 Instruments
2.1.1 Bearings: 7604 type bearings or Timken tapered roller bearings (cone No. 09074, outer ring No. 09196), selected according to product standards.
2.1.2 Glass bottle: 70 mm in diameter, 86 mm in height, with a waxed screw cap. 2.1.3 Bearing bracket: tapered glass seat with a taper of 14/35 to 19/38. 2.1.1 Motor: speed of 1450 rpm or 1750 rpm, 1/4 horsepower. 2.1.5 Spindle: connected to the motor shaft with a punched No. 4 rubber plug. 2.1.6 Thrust loader: as shown in Figure 1. The calibration method is to stand the thrust loader handle and thrust loader together. Clamp the handle with a vise, add a 2.7 kg weight to the cup, and mark the cylinder to determine the corresponding handle position. National Bureau of Standards 1985-03
-26 Issued
1985-1201 Implementation
2.1.7 Mechanical greaser: As shown in Figure 2
Assembly parts
GB/T 5018
20.64 ± 0.02
A—A Section
Figure 1 Thrust loader
1 Rod (brass); 2 Handle (aluminum); 3 Side cylinder (steel); 4 Spring (steel wire) 5 turns per 25.4 mm; 5 Cup (aluminum), 6 Disc (brass)
Drilling diameter is 3.97 Depth:
Drill through 8 holes, the hole axis interruption in the symmetrical position
is 30.16
19°6F9
Simple (brass)
A-\A Shaved
Figure 2 Mechanical greaser
Bolt (yellow)
2.2 Reagents
GB/T 5018--- 85
2.2.1 Solvent gasoline (Note: flammable, vapor is harmful, see Appendix A (reference) A.1). 2.2.2 Isopropyl alcohol (Note: flammable, see Appendix A (reference) A.2): chemically pure. 2.2.3 Ammonium hydroxide: chemically pure.
Solvent flushing liquid, composition as follows (by volume percentage): 2.2.4
Isopropyl alcohol: 90%;
Distilled water: 9%:
Ammonium hydroxide: 1%.
3 Preparation
3.1 The test bearings should be carefully inspected and completely corrosion-free bearings should be selected. The bearings should be manipulated with a fixture during the entire preparation process and should not be touched with fingers at any time.
3.2 Thoroughly clean the selected bearings with solvent gasoline to remove the rust inhibitor. To ensure that the rust inhibitor is completely removed, clean the bearings with new solvent gasoline several times.
3.3 Transfer the bearing from the solvent gasoline to the solvent rinse solution, removing the solvent gasoline and any fingerprints that may be present. The bearing should be rotated slowly during the rinse.
3.4 ​​Remove the bearing from the solvent rinse solution, place it on filter paper, absorb F, and dry it in an oven at 71°C for 15 to 30 minutes. 3.5 Allow the bearing to cool to room temperature and check the bearing surface again to ensure that the selected bearing is flexible and corrosion-free (after cleaning and drying, be careful not to let the bearing rotate when handling it). 3.6 Clean and dry the thrust loader and bearing greaser in the same way as the bearing preparation method. Note: For rust inhibitors that are difficult to remove, hot solvent gasoline (52 to 66°C) and hot solvent rinse solution (minimum 66°C) can be used for cleaning, but the cleaning operation should be carried out in a well-ventilated hood and without open flames or other ignition sources. 4 Test procedures
4.1 Three new bearings are required for each test. The bearings (the total of the cone and the outer ring) are weighed to the nearest 0.1 gram. Use clean oil-resistant gloves (such as polyethylene gloves) when handling the bearing.
4.2 Use a mechanical greaser (as shown in Figure 2) to fill the sample into the assembled bearing. 4.3 Remove excess grease, install the assembled bearing into the thrust loader (as shown in Figure 1), and lock the bearing with the locking screw. 4.4 Push the bearing cone against the rubber plug on the code shaft, and push the thrust loader handle to the calibrated mark on the cylinder so that the thrust load is 26.7 tons.
4.5 Rotate the bearing at 1450 rpm for 10 seconds, turn off the motor and let it inertially rotate to a stop, then remove the bearing from the spindle, loosen the locking screw, and push the bearing out of the cup with a push rod. 4.6 Remove excess grease, redistribute the sample evenly, and adjust the weight of grease on the cone and outer ring assembly to 2.1 ± 0.1 cm (2.0 ± 0.1 g). Then, apply a thin layer of grease (about 0.1 g) to the outer surface of the assembled bearing. Note: When the density of the test grease is significantly greater than that of the mineral oil-based grease, adjust the grease weight to 2.1 ± 0.1 cm. 4.7 Install the bearing into the thrust loader, lock it with the locking screw, and rotate the bearing for 1 minute according to steps 4.4 and 4.5. Be very careful when removing the bearing. Do not separate the roller and outer ring at this time and in the following steps. Note: During operation or after 1 minute of operation, the grease should never be spread or pressed back into the bearing. 4.8 Install the bearing on the bearing bracket. The weight of the outer ring of the bearing itself will ensure that the outer ring and the roller element remain in contact. Hold the bracket and immerse the entire assembly in distilled water that has been boiled and cooled to room temperature for 10 seconds (use new distilled water for each bearing). 4.9 Allow water to exist on the bearing. Place the assembly in a glass bottle containing 5 ml of distilled water, cover the bottle tightly, and place it in a substantially vibration-free oven at 52 ± 1°C for 48 hours. Note: During operation, the bearing should be prevented from contacting the bottle wall and rotating. 4.10 After the test time is reached, remove the bearing from the bottle, place the outer ring of the bearing in a mixture of isobutyl alcohol and solvent gasoline in a volume ratio of 50:50 (the mixture can be heated), clean the grease on the bearing, and repeatedly clean it with new mixture to ensure that traces of grease are removed. 4.11 Transfer the outer ring of the bearing from the solvent to a clean filter paper and dry it. 5 Rating
Check the signs of corrosion on the outer ring raceway of the bearing (see Chapter 1). No corrosion is level 1, initial corrosion, no more than 3 spots visible to the naked eye are level 2, and larger or more spots are level 3. NOTE: Spots that are easily removed by gentle rubbing with soft cotton wool (dry or with a rag moistened with any solvent that does not react to rust or steel at room temperature) are not considered corrosion for the purpose of rating.
6 Reporting
If the results of the inspection on two or three bearings agree, this value should be reported as the result of the specimen. If the results of the inspection on all three bearings are different, the test should be repeated.
7 Precision
7.1 Repeatability can be judged by the fact that 91% of the repeated results obtained from 4 specimens in 9 laboratories are in agreement. 7.2 Reproducibility can be judged by the fact that at least 94% of the results from 16 laboratories on 6 specimens with good or poor corrosion protection are in agreement with each other. However, for the 2 card edge specimens, only 73% of the results are in agreement. 481
A.1 Solvent gasoline
GB/T 5018
Appendix A
Instructions for use of reagents
(reference)
Solvent gasoline is flammable and should be kept away from heat sources, sparks and open flames. Keep the container closed.
Pay attention to good ventilation when using.
The vapor is harmful. Avoid inhaling vapor or mist. e.
Avoid prolonged or repeated contact with skin.
Isopropyl alcohol
Isopropyl alcohol is flammable and should be kept away from heat sources, sparks and open flames. b.
Keep container tightly closed.
Ensure good ventilation during use. www.bzxz.net
Avoid prolonged inhalation of vapor or mist.
Avoid contact with eyes or skin.
Do not take orally.
Additional remarks:
This standard is proposed by China Petrochemical Corporation. This standard is under the jurisdiction of the Petrochemical Research Institute. This standard was drafted by the Petrochemical Research Institute. The main drafters of this standard are Jin Baoyin and Li Xianming. This standard adopts the American Society for Testing and Materials standard ASTM D1743-1973 (81) "Test Method for Anticorrosive Properties of Greases". 482
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