SH/T 0573-1993 Test method for wear particles in in-service lubricating oils (analytical ferrography)

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 0573-93 (confirmed in 2003)
• Chinese name: Test method for wear particles in in-service lubricating oils (analytical ferrography)
• English name: not provided in the available source
• Replacement relationship: not provided in the available source
• Approval/implementation: approved by China Petrochemical Corporation 1993-08-19, implemented on 1994-05-01

2. Scope of application and non-applicability

• Applicable to analyzing the morphology, size, and concentration change trend of wear particles generated by mechanical components during the use of oils such as internal combustion engine oils, gear oils, and hydraulic oils.
• Not applicable: not provided in the available source.

3. Method principle

Under the action of the magnetic field of an analytical ferrograph, wear particles in in-service lubricating oil are deposited on a substrate, and then the morphology, size, and coverage area of the wear particles are observed and measured under a ferrographic microscope to analyze the wear condition of the machinery.

4. Reagents and materials (purity / preparation)

• 5.1 Tetrachloroethylene: analytical reagent.
• 5.2 Solvent naphtha: complies with the provisions in SH 0004.
• 5.3 Pipette: 1 mL (the source text reads "1MLo", requires confirmation against the source standard (source-text extraction)).
• 5.4 Test tube: diameter 15 mm, length 150 mm; diameter 10 mm, length 100 mm (the source text reads "lomm" "l00mm", requires confirmation against the source standard (source-text extraction)).
• 5.5 Substrate: a glass slide of 60 mm × 24 mm × 0.17 mm, with a U-shaped flow-restricting groove on the surface that is not wetted by oil.
• 5.6 Microporous membrane: the material is filter paper or another oil-insoluble microporous membrane material, diameter 50 mm, pore size not greater than 0.8 μm (the source text reads "。.81amo", requires confirmation against the source standard (source-text extraction)).
• 5.7 Oil delivery conduit: the conduit material is fluorosilicone rubber or polytetrafluoroethylene, diameter 1.0～1.2 mm (the conduit diameter and unit are unclear in the source transcription and require verification).
• Dilution oil: new oil of the same type as the sample, pre-filtered with a microporous membrane (see note to 7.2.1).

5. Instruments and equipment

• 6.1 Analytical ferrograph.
• 6.2 Ferrographic microscope.
• 6.3 Ferrogram slide heater.
• 6.4 Drying oven.
• Densitometer (see 7.6.1).

6. Recommended operating conditions

• Sample mixing temperature: 65 ℃±5 ℃, maintained for 30 min (7.1).
• Sample flow rate: 25 mL/h (the source text reads "25mUho", requires confirmation against the source standard (source-text extraction)) (7.3.3).
• Ferrogram slide heater temperature: 330 ℃±10 ℃ (7.5.1).
• Ferrogram slide heating time: 90 s (the source text reads "9050", requires confirmation against the source standard (source-text extraction)) (7.5.2).
• Objective lens for densitometer measurement: 10× (7.6.2).

7. Sampling and sample preparation

• 7.1 Sample mixing: keep the sample in the oil sample bottle (not exceeding 3/4 of the bottle capacity) in a drying oven at 65 ℃±5 ℃ for 30 min, then shake thoroughly to mix the sample uniformly.
• 7.2 Sample dilution:
  • 7.2.1 Immediately after the sample is uniformly mixed, take a sample of 1 mL with a pipette and dilute it in a clean test tube, according to dilution oil to sample volume ratios of 9:1, 19:1, 29:1, etc. Note: the dilution oil is new oil of the same type as the sample, pre-filtered with a microporous membrane.
  • 7.2.2 The diluted oil sample must be heated and shaken uniformly, transferred to another test tube, and further diluted with tetrachloroethylene solvent; after shaking uniformly, it is used as the test specimen. The amount of solvent used is a solvent to specimen volume ratio of 1:30.
• 7.3 Preparation of ferrogram slides:
  • 7.3.1 Place the test tube containing the diluted specimen on the sample rack of the analytical ferrograph, and insert the oil delivery conduit to the bottom of the specimen in the test tube.
  • 7.3.2 Place the substrate, connect the flow guide tube, and position the outlet of the oil delivery conduit above the inlet area of the substrate.
  • 7.3.3 Turn on the power switch of the ferrograph to make the specimen flow, at a flow rate of 25 mL/h.
  • 7.3.4 After the specimen has finished flowing, add 2～4 mL tetrachloroethylene solvent to the test tube for cleaning.
  • 7.3.5 After cleaning is completed, wait until the solvent on the substrate has completely evaporated, turn off the power switch, and remove the ferrogram slide vertically upward.
  • Note: During the preparation of the ferrogram slide, attention must be paid to dust prevention, vibration prevention, and ventilation.

8. Analysis procedure

• 7.4 Qualitative analysis of wear particles:
  • 7.4.1 Place the ferrogram slide on the stage of the ferrographic microscope, turn on the reflected and transmitted light sources, adjust to appropriate brightness, slowly adjust the object distance until the particles on the ferrogram slide are clearly visible, and use different magnifications as needed to observe the size distribution and morphology of the wear particles.
  • 7.4.2 Characteristics of normal wear particles: thin flakes, smooth surface, fine and uniform particles, major axis size 0.5～15 μm, thickness 0.15～1 μm. During the mechanical running-in stage, some elongated and flat particles are also produced; such particles also belong to normal wear particles.
  • 7.4.3 Characteristics of cutting wear particles: linear, curled, arc-shaped, turnings-like, elongated. When the hard friction surface has sharp edges, relatively coarse cutting wear particles are produced, with length 25～100 μm and width 2～5 μm; when there is a hard inclusion between two friction surfaces, relatively fine cutting wear particles are produced, with length 5～10 μm and thickness about 0.25 μm.
  • 7.4.4 Rolling fatigue wear particles have three morphologies: fatigue spalling fragments, spherical particles, and lamellar particles.
    • 7.4.4.1 The major axis size of fatigue spalling fragments is generally greater than 10 μm, and can reach up to 100 μm; the shape factor is less than 5:1, and they have one smooth surface and irregular periphery.
    • 7.4.4.2 The diameter of spherical particles is generally 1～3 μm, and can reach up to 10 μm.
    • 7.4.4.3 Lamellar particles are flat thin flakes, with major axis size 20～50 μm, shape factor greater than 30:1, and some cavities on the particle surface.
  • 7.4.5 Characteristics of severe sliding wear particles: major axis size above 20 μm, shape factor greater than 5:1 and less than 30:1, obvious sliding striations on the surface, and sometimes colors caused by high temperature.
  • 7.4.6 Characteristics of non-ferrous metal wear particles: the particles are not arranged along the direction of the magnetic field, but deposit in a random manner; most of them deviate from the ferromagnetic wear particle chains or are located between two adjacent chains, and they often carry the characteristic color of the non-ferrous metal itself.
  • 7.4.7 Iron oxides: red oxide particles appear as reddish-brown polycrystalline aggregates under white polarized light, with the main component being α-Fe2O3 (the oxide formula is garbled in the source transcription; its interpretation as alpha iron(III) oxide remains unverified); black oxide particles appear black under white reflected light, with small blue and orange spots on the surface, and the main component is a mixture of Fe3O4, α-Fe2O3, and FeO in non-fixed proportions (the oxide-mixture formulas are unclear in the source transcription; verify the displayed interpretation before use).
  • 7.4.8 Characteristics of friction polymers: under bichromatic light, metal wear particles embedded in an amorphous colloid can be observed; the metal wear particles appear red, while the colloid appears transparent green.
  • 7.4.9 Characteristics of corrosive wear particles: the particles are very fine; even at a magnification of 100×, individual particles are not easily distinguished; the particles accumulate on both sides of the exit area of the ferrogram slide and can be observed throughout the entire ferrogram slide (the source text reads "100〕", requires confirmation against the source standard (source-text extraction)).
  • 7.4.10 Cutting wear particles, fatigue wear particles, severe sliding wear particles, corrosive wear particles, and metal oxides all belong to abnormal wear particles; their large-scale appearance means that the wear of the machinery is severe.
• 7.5 Heating analysis of the ferrogram slide:
  • 7.5.1 Adjust the ferrogram slide heater so that the temperature reaches 330 ℃±10 ℃.
  • 7.5.2 Place the ferrogram slide on the ferrogram slide heater and heat for 90 s.
  • 7.5.3 Observe under the ferrographic microscope the characteristic temper colors of the oxide layer generated on the surface of the wear particles; usually under white reflected light, cast iron wear particles appear straw yellow, and low-alloy steel wear particles appear blue.
• 7.6 Determination of the percentage coverage area of the ferrogram slide:
  • 7.6.1 Install the densitometer and calibrate the instrument according to the instrument manual.
  • 7.6.2 Use a 10× objective lens, move the stage, and use the densitometer to measure the AL and As values of the ferrogram slide.
  • Note: If the measured result AL value is greater than 30% or less than 10%, the ferrogram slide should be prepared again.

9. Qualitative and quantitative and calculation formulas

• 8.1 The percentage coverage areas of large particles and small particles per milliliter of oil sample, A'L and A's (%), are calculated respectively according to formula (1) and formula (2):
  • The original formula layout is missing; only the forms "A'L = AL / M" and "A's = As / M" are seen (the formula layout and symbols are incomplete in the source transcription; verify the displayed interpretations before calculation).
  • Where: M—— volume of sample flowing through the substrate, mL.
• 8.2 The total wear value of mechanical wear T (%) is calculated according to formula (3): T = A'L + A's (the total-wear formula and symbols are unclear in the source transcription; verify the displayed interpretation before calculation).
• 8.3 Wear severity of mechanical wear S (%) is calculated according to formula (4): S = A'L − A's (original text "S=A', one A}F", requires confirmation against the source standard (source-text extraction)).
• 8.4 Wear intensity index of mechanical wear Ia is calculated according to formula (5): Ia = T · S (original text "Ia= T ·S").

10. Precision

not provided in the available source.

11. Report

• 9.1 Report the size, morphology, type, composition, and quantity of wear particles.
• 9.2 Report the percentage coverage area of large particles and small particles per milliliter of oil sample, total wear value, wear severity, and wear intensity index values.
• 9.3 Based on the test results, analyze the mechanical wear condition.

12. Normative references

• SH 0004 Rubber industry 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 for questions and answers