SH/T 0060-1991 Determination of oxygen absorption of rust-preventive grease (oxygen bomb 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

• Standard number: SH/T 0060-91 (confirmed in 2000)
• Chinese name: Determination of oxygen absorption of rust-preventive grease (oxygen bomb method)
• English name: not provided in the available source
• Replacement relationship: not provided in the available source
• Reference adoption: oxygen absorption test method in clause 5.18 of Japanese Industrial Standard JIS K 2246—89 "Rust Preventive Oil" (see additional notes)
• Approval/implementation: approved by China Petrochemical Corporation 1991-06-28, implemented on 1992-07-01

2. Scope of application and non-applicability

• Applicable to: rust-preventive grease, rust-preventive lubricating grease.
• Not applicable to: not provided in the available source.

3. Method principle

The sample is oxidized in an oxygen bomb heated to 99℃ and filled with 760kPa (7.7kgf/cm², original text is "7.7kgf/cm?", requires confirmation against the source standard (source-text extraction)) oxygen, and the pressure is observed and recorded at specified time intervals. After 100h, the corresponding decrease in oxygen pressure represents the degree of oxygen absorption of the sample.

4. Reagents and materials (purity / preparation)

• Oxygen: purity not lower than 99.5%.
• Small brass discs: made from H68 brass plate in GB 5232, diameter 33mm, thickness 1.2mm, treated immediately before use.
• Emery cloth (or emery paper): grit 240.
• Washing solvent: meets the requirements of SH 0004, or 90~120℃ petroleum ether.
• Methanol or anhydrous ethanol: analytical reagent.
• Desiccator: use silica gel as desiccant.

5. Apparatus and equipment

• Oxygen bomb, pressure gauge, dish rack, sample dishes and oil bath: see Appendix A.
• Thermometer: temperature range 95~103℃, scale division 0.1℃, technical conditions see Appendix B.
• Desiccator: use silica gel as desiccant.
• Appendix A equipment key points:
  • Oxygen bomb: corrosion-resistant and pressure-resistant stainless steel airtight vessel, including bomb body, pressure gauge gas guide tube with bomb cover, oxygen bomb fastening nut and gasket; structure see Figure A1, Figure A2.
  • Bomb body and bomb cover (flat cover): machined from stainless steel, inner surface polished; capable of withstanding 3.92MPa (40kgf/cm²) hydrostatic test, should be able to withstand 1241kPa (12.7kgf/cm²) pressure under 99℃; volume without sample dish and dish rack should be (185±6)mL (measured to the gasket contact surface of the pressure gauge gas guide tube).
  • Pressure gauge gas guide tube: made of stainless steel, inner wall polished, dimensions see Figure A2, upper part equipped with needle valve.
  • Oxygen bomb fastening nut: made of stainless steel.
  • Oxygen bomb support plate: outer diameter about 114mm, made of stainless steel.
  • "O" type sealing ring: made of polytetrafluoroethylene, inner diameter 51mm, outer diameter 58mm.
  • Pressure gauge: indicating type (or recording type) pressure gauge suitable for oxygen, accuracy class 0.4, size 150mm, measuring range 0~1MPa, minimum scale 5kPa.
  • Dish rack and glass sample dishes: dish rack made of stainless steel, dimensions see Figure A3.
  • Constant-temperature oil bath: capable of controlling 99℃±0.5℃, oil bath temperature gradient less than 0.5℃; sufficient depth, equipped with electric stirrer, electric heater and temperature controller; oil bath cover has thermometer insertion hole and oxygen bomb insertion hole; thermometer 96.8℃ position at the same level as the upper surface of the oil bath cover; adjust the oil bath surface so that the oxygen bomb is immersed about 50mm below the oil surface.
  • Tools for fastening the oxygen bomb: wrench and oxygen bomb fixing table, dimensions see Figure A4.
• Appendix B thermometer specifications: range 95–103℃; calibration point temperature 99℃; total immersion; scale division 0.1℃; length scale value 0.5; each scale (scale number) 1; scale error not greater than 0.1; expansion chamber permitted to be heated to 155℃; total length 270–280mm; stem diameter 6.0–7.0mm; mercury bulb length 25–35mm; mercury bulb diameter not less than 5.0 and not greater than stem diameter; distance from bottom of scale positioning bulb to scale 95.6mm; bulb bottom length 135–150mm; distance from bulb bottom to contraction chamber bottom (maximum) 70–100mm; stem enlarged part diameter 60mm, length 8.0–10.0mm, distance to bottom 4.0–7.0mm, 112~116mm (the arrangement of this group of data in the original text is rather disordered, requires confirmation against the source standard (source-text extraction)).

6. Recommended operating conditions

• Oxidation temperature: 99℃.
• Oil bath temperature: 99℃±0.5℃.
• Initial oxygen pressure: 760kPa±5kPa.
• Test time: 100h.
• Pressure recording interval: observe and record pressure at least every 24h.

7. Sampling and sample preparation

• Sample amount: fill with molten sample 4.00g±0.01g.
• Treatment of small brass discs (6.1):
  • 6.1.1 Immerse the small brass disc in washing solvent, wipe with gauze, and clean off the previous sample and dust.
  • 6.1.2 Under dry conditions, repeatedly polish with 240 grade emery cloth or emery paper (in the same direction) until a new polished surface is produced.
  • 6.1.3 After removing sand particles, immerse in washing solvent, scrub with gauze until clean; after drying with warm air, immediately immerse in boiling methanol or anhydrous ethanol for about 1min, and after drying with warm air it is ready for use.
  • 6.1.4 Treated small brass discs not used temporarily should be stored in a desiccator, but after more than 24h they must be re-polished.
• Cleaning of sample dishes (6.2): clean sequentially with washing solvent, hot soapy water and cleaning solution, then rinse with tap water, and finally rinse with distilled water; after cleaning, dry in an oven; cleaned sample dishes may only be touched with tweezers.
• Cleaning of the inner surface of the oxygen bomb and dish rack (6.3): before the test, if paint film is found, immerse in hot washing solvent, scrub with a brush, and dry; further wash with soapy water until all paint film is removed; then rinse with tap water, then rinse with distilled water, and dry in an oven; cleaned dish racks may only be touched with tweezers.

8. Analytical procedure

• 7.1 Take 10 small brass discs treated according to clause 6.1 from the desiccator, and place them respectively at the bottom of 10 sample dishes. Fill with molten sample 4.00g±0.01g. Place the sample dishes containing the sample respectively on the bottom shelf of the dish rack, leaving the top shelf as a cover to prevent condensed volatile matter from dripping into the sample. When assembling the oxygen bomb, place a small wad of glass wool at the bottom of the pressure gauge gas guide tube.
• 7.2 Place the dish rack with sample dishes into the oxygen bomb. Tighten the oxygen bomb to seal it. Slowly introduce oxygen until the pressure reaches 690kPa (7.0kgf/cm²). Then slowly let the oxygen escape. Repeat the operation four times to expel air from the oxygen bomb. After the fifth oxygen pressure reaches 690kPa, close the needle valve tightly, leave for several hours or immerse the oxygen bomb in water to check for leakage.
• 7.3 After confirming that the oxygen bomb does not leak, place the oxygen bomb in an oil bath maintained at 99℃±0.5℃. When the pressure rises above 765kPa, intermittently release oxygen from the oxygen bomb until the pressure stabilizes at 760kPa±5kPa and is maintained for at least 2h (if the pressure gradually decreases, it indicates that the oxygen bomb is still leaking, and leakage must be checked again).
• 7.4 After the pressure of the oxygen bomb in the oil bath has been stable for 2h, record the pressure and start timing. Read the oxygen pressure at 100h. Observe and record the pressure at least every 24h.

9. Qualitative and quantitative determination and calculation formula

Subtract the oxygen pressure (gauge pressure) after the 100h test from the oxygen pressure (gauge pressure) after immersing the oxygen bomb in the oil bath for 2h; this is the degree of oxygen absorption, expressed in units of kPa.

10. Precision

not provided in the available source.

11. Report

Take the arithmetic mean of the pressure drops (kPa) from two oxygen bomb tests as the test result.

12. Referenced documents

• GB 5232 Wrought brass — chemical composition and product forms (editor's note: current standard number is GB/T 5231, current standard name is "Wrought copper and copper alloys — chemical composition and product forms")
• SH 0004 Solvent naphtha for rubber industry
• Reference: JIS K 2246—89 "Rust Preventive Oil" clause 5.18 oxygen absorption test method

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