SH/T 0204-1992 Determination of anti-wear properties of lubricating grease (four-ball machine method)

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full name / English name / replacement relationship

• Method number: SH/T 0204-92
• Full name: Determination of anti-wear properties of lubricating grease (four-ball machine method)
• English name: not provided in the available source
• Replacement relationship: replaces ZB E36 021-89
• Other: confirmed in 2004; reference adoption of ASTM D2266-67 (81) "Determination of anti-wear properties of lubricating grease (four-ball machine method)"

2. Scope of application and non-applicability

• Applicable: evaluation of the anti-wear properties of lubricating grease on steel-on-steel friction pairs on a four-ball testing machine.
• Not applicable: cannot be used to distinguish extreme-pressure lubricating greases from non-extreme-pressure lubricating greases.

3. Method principle

Under load, one upper steel ball rotates against three stationary lower steel balls whose surfaces are coated with the test lubricating grease (sample). After the test, the wear scar diameters of the three lower steel balls are measured, and the anti-wear properties of the lubricating grease are judged by the magnitude of the average wear scar diameter.

4. Reagents and materials (purity / preparation)

• Steel balls: test steel balls specially used for the four-ball machine, made of high-quality chromium alloy bearing steel GCr15, diameter 12.7 mm, Rockwell hardness HRC 64～66.
• Solvent naphtha: meets the requirements of No. 190 in GB 1922.
• Petroleum ether: 60～90 ℃, analytical reagent; or solvent naphtha, meeting the requirements of No. 90 in GB 1922.

5. Instruments and equipment

• Wear four-ball machine: spindle speed not less than 1200 r/min, load not less than 392 N (40 kgf); after the spring chuck loaded with steel balls is installed in the spindle taper hole of the testing machine, the radial circular runout of the steel balls shall not be greater than 0.015 mm; an extreme-pressure four-ball machine proven by testing to have precision meeting the requirements of this method may also be used. The schematic diagram of the testing machine principle is shown in the original text (original figure, source-text extraction noise, requires confirmation against the source standard).
• Microscope: equipped with a calibrated micrometer, with a division value of 0.01 mm.
• Timer.

6. Recommended operating conditions

• Test temperature: 75 ℃±2 ℃
• Spindle speed: 1200 r/min±50 r/min
• Test load: 392 N±2 N (40 kgf±0.2 kgf)
• Test time: 60 min±1 min
• Note: Although the test may be carried out under other conditions, the precision described in Chapter 8 applies only to the conditions described in Clause 7.1.

7. Sampling and sample preparation

• Test preparation: start the motor, adjust the spindle speed to 1200 r/min±50 r/min, and run idle for 2～3 min.
• Cleaning: clean the steel balls, ball box, chuck, and other parts that contact the sample during the test with solvent naphtha, then wash twice with petroleum ether, and then blow dry for later use; the cleaned steel balls should be smooth and free of rust spots.
• Sample loading: fill the ball box with the sample, avoiding the introduction of air bubbles; place three clean steel balls into the ball box, carefully press the fixing ring onto the three steel balls, tighten the lock nut, fix the three steel balls in the proper position, and scrape away excess sample squeezed out from the fixing nut so that it is flush with the top surface of the lock nut.

8. Analytical procedure

• 7.3 Place one clean steel ball into the chuck, then firmly fix the chuck on the spindle of the testing machine.
• 7.4 Place the ball box on the ball box seat of the testing machine, then bring the top ball into contact with the three steel balls in the ball box, and apply the specified load.
• 7.5 Adjust the temperature controller to the specified temperature 75 ℃, turn on the heater, and when the temperature is reached, start the motor and run for 60 min±1 min.
  • Note: After the motor is started, the temperature may rise rapidly and exceed the preset temperature. In this case, the temperature set value must be adjusted lower to avoid exceeding the given temperature due to frictional heating at the beginning of the test.
• 7.6 After running for 60 min, turn off the motor and heater, lower the ball box assembly, and remove the ball box.
• 7.7 After each test, measure the wear scar diameter of the test balls as follows:
  • 7.7.1 A method: remove the fixing nut, take out the test balls, wipe clean the sample, place the balls on a suitable ball seat, and use a microscope to measure the wear scar diameter of each of the three steel balls at two positions (two directions perpendicular and parallel to the rotation direction), accurate to 0.01 mm, and report the arithmetic mean of the six readings as the wear scar diameter (mm).
  • 7.7.2 B method: leave the test balls in the ball box, wipe clean the test balls and excess sample in the ball box with a soft cloth or paper, and measure and report the wear scar diameter according to the procedure specified in method A (mm).
  • Note: If the difference between the two measured values of the wear scar diameter of one steel ball and the average of the six measurements of the wear scar diameters of the three steel balls is greater than 0.04 mm, the testing machine should be adjusted.

9. Qualitative and quantitative determination and calculation formula

• The anti-wear properties of the lubricating grease are judged by the magnitude of the average wear scar diameter.
• Result reporting: take the arithmetic mean of the two results of duplicate tests as the determination result.
• Calculation formula: not provided in the available source.

10. Precision

Judge the reliability of the test results according to the following provisions (95% confidence level):

• 8.1 Repeatability: the difference between two test results obtained by the same operator using the same equipment under the specified operating conditions on the same sample shall not exceed 0.20 mm.
• 8.2 Reproducibility: the difference between two test results obtained by different operators in different laboratories on the same sample shall not exceed 0.37 mm (the original text source-text extraction is "0. 37= .", requires confirmation against the source standard (source-text extraction)).

11. Report

Take the arithmetic mean of the two results of duplicate tests as the determination result.

12. Referenced documents

• GB 1922 Solvent naphtha

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick-reference Q&A