1、Designation: D7684 11Standard Guide forMicroscopic Characterization of Particles from In-ServiceLubricants1This standard is issued under the fixed designation D7684; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers the classification and reporting ofresults from in-service lubricant particulate debris analysisobtained
3、by microscopic inspection of wear and contaminantparticles extracted from in-service lubricant and hydraulic oilsamples. This guide suggests standardized terminology topromote consistent reporting, provides logical framework todocument likely or possible root causes, and supports inferenceassociated
4、 machinery health condition or severity based onavailable debris analysis information.1.2 This guide shall be used in conjunction with an appro-priate wear debris analysis sample preparation and inspectiontechnique including, but not limited to, one of the following:1.2.1 Ferrography using linear gl
5、ass slides,1.2.2 Ferrography using rotary glass slides,1.2.3 Patch analysis using patch makers (filtration throughmembrane filters),1.2.4 Filter debris analysis,1.2.5 Magnetic plug inspection, or1.2.6 Other means used to extract and inspect particulatedebris from in-service lubricants.1.3 This stand
6、ard is not intended to evaluate or characterizethe advantage or disadvantage of one or another of theseparticular particle extraction and inspection methods.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.5 This standard d
7、oes not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM St
8、andards:2D4130 Test Method for Sulfate Ion in Brackish Water,Seawater, and BrinesD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD7416 Practice for Analysis of In-Service Lubricants Usinga Particular Five-Part (Dielectric Permittivity, Time-Resolved Dielectric Permittivity
9、with Switching MagneticFields, Laser Particle Counter, Microscopic Debris Analy-sis, and Orbital Viscometer) IntegraD7596 Test Method for Automatic Particle Counting andParticle Shape Classification of Oils Using a Direct Imag-ing Integrated TesterD7647 Test Method for Automatic Particle Counting of
10、Lubricating and Hydraulic Fluids Using Dilution Tech-niques to Eliminate the Contribution of Water and Inter-fering Soft Particles by Light ExtinctionD7690 Practice for Microscopic Characterization of Par-ticles from In-Service Lubricants by Analytical Ferrogra-phyG40 Terminology Relating to Wear an
11、d Erosion2.2 ISO Standard:3ISO 11171 Hydraulic fluid power Calibration of auto-matic particle counters for liquids3. Terminology3.1 Definitions:3.1.1 abrasive wear, nwear due to hard particles or hardprotuberances forced against and moving along a solid surface.G401This guide is under the jurisdicti
12、on of ASTM Committee D02 on PetroleumProducts and Lubricants and is the direct responsibility of Subcommittee D02.96.06on Practices and Techniques for Prediction and Determination of Microscopic Wearand Wear-related Properties.Current edition approved Jan. 1, 2011. Published March 2011. DOI: 10.1520
13、/D768411.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from International Organization for Stand
14、ardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, www.iso.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.2 abrasion, nwear by displacement of material causedby hard particles or har
15、d protuberances. D41753.1.3 break-in, nsee run-in. G403.1.4 fatigue wear, nwear of a solid surface caused byfracture arising from material fatigue. G403.1.5 fretting, nin tribology, small amplitude oscillatorymotion, usually tangential, between two solid surfaces incontact.3.1.5.1 DiscussionHere the
16、 term fretting refers only to thenature of the motion without reference to the wear, corrosion,or other damage that may ensue. The term fretting is often usedto denote fretting corrosion and other forms of fretting wear.Usage in this sense is discouraged due to the ambiguity thatmay arise. G403.1.6
17、fretting wear, nwear arising as a result of fretting(see fretting). G403.1.7 lubricant, nany material interposed between twosurfaces that reduces the friction or wear between them.D41753.1.8 lubricating oil, nliquid lubricant, usually compris-ing several ingredients, including a major portion of bas
18、e oiland minor portions of various additives. D41753.1.9 rolling, vmotion in a direction parallel to the planeof a revolute body (ball, cylinder, wheel, and so forth) on asurface without relative slip between the surfaces in all or partof the contact area. G403.1.10 rolling contact fatigue, ndamage
19、process in atriboelement subjected to repeated rolling contact loads, in-volving the initiation and propagation of fatigue cracks in orunder the contact surface, eventually culminating in surfacepits or spalls. G403.1.11 run-in, nin tribology, an initial transition processoccurring in newly establis
20、hed wearing contacts, often accom-panied by transients in coefficient of friction or wear rate, orboth, that are uncharacteristic of the given tribological systemsbehavior. Syn. break-in and wear-in. G403.1.12 rust, nof ferrous alloys, a corrosion product con-sisting primarily of hydrated iron oxide
21、s. D41753.1.13 sliding wear, nwear due to the relative motion inthe tangential plane of contact between two solid bodies.G403.1.14 sludge, nprecipitate or sediment from oxidizedmineral oil and water. D41303.1.15 spalling, nin tribology, the separation of macro-scopic particles from a surface in the
22、form of flakes or chips,usually associated with rolling element bearings and gear teeth,but also resulting from impact events. G403.1.16 three-body abrasive wear, nform of abrasive wearin which wear is produced by loose particles introduced orgenerated between the contacting surfaces.3.1.16.1 Discus
23、sionIn tribology, loose particles are con-sidered to be a “third body.” G403.1.17 two-body abrasive wear, nform of abrasive wearin which the hard particles or protuberances that produce thewear of one body are fixed on the surface of the opposing body.G403.1.18 wear, ndamage to a solid surface, usua
24、lly involv-ing progressive loss or displacement of material, due to relativemotion between that surface and a contacting substance orsubstances. D4175, G403.2 Definitions of Terms Specific to This Standard:3.2.1 abrasive wear particles, nlong wire-like particlesin the form of loops or spirals that a
25、re generated due to hard,abrasive particles present between wearing surfaces of unequalhardness; sometimes called cutting wear particles or ribbons.3.2.2 analytical ferrography, ntechnique whereby par-ticles from an oil sample deposited by a ferrograph areidentified to aid in establishing wear mode
26、inside an oil-wettedpath of a machine.3.2.3 chunks, nfree metal particles 5 m with a shapefactor (major dimension to thickness ratio) of 15 m and several times longer thanthey are wide. Some of these particles have surface striations asa result of sliding and they frequently have straight edges.Thei
27、r major dimension-to-thickness ratio is approximately10:1.3.2.29 severe wear particles, nin tribology, free metalparticles 15 m with major dimension-to-thickness ratiosbetween 5:1 and 30:1.3.2.30 spheres, nin tribology, metal spheres may be theresult of incipient rolling contact fatigue or they may
28、becontaminant particles from welding, grinding, coal burning,and steel manufacturing. Spheres may also be caused byelectro-pitting.3.2.31 wear particles, nparticles generated from a wear-ing surface of a machine.4. Summary of Guide4.1 Periodic in-service lubricant samples are collected froma machine
29、 as part of a routine condition monitoring program.The sample is prepared to separate particles from the samplefluid. The separated particles are subsequently examined usingan optical microscope to identify the types of particles presentto aid in identifying the wear mode occurring in the oil-wetted
30、path of the machine.4.2 In usual practice of a routine condition monitoringprogram, particle separation and examination is not done forevery sample taken, but may be done when routine tests suchas spectrometric analysis, particle counting, or ferrous debrismonitoring indicate abnormal results.4.3 Th
31、is guide is to be used with a sample preparationmethod that extracts particulate debris from in-service lubri-cant systems for subsequent microscopic examination.4.4 The user of this guide should employ consistent termi-nology to achieve accepted and understandable interpretationswhen communicating
32、instructions and findings based on par-ticle analysis.4.5 Aprocess is suggested in standardized format to identifyand further classify multiple distinct groups of particulatedebris extracted from an in-service machinery lubricatingsample.4.6 A grid format is suggested in which the user of thisguide
33、can present findings and report possible root causesalong with an assessment of associated machinery healthcondition or severity based on available debris analysis infor-mation.4.7 An alternate classification scheme is suggested that isconsistent with Practice D7690.5. Significance and Use5.1 The ob
34、jective of particle examination is to diagnose theoperational condition of the machine sampled based on thequantity and type of particles observed in the oil. Afterbreak-in, normally running machines exhibit consistent particleconcentration and particle types from sample to sample. Anincrease in par
35、ticle concentration, accompanied by an increasein size and severity of particle types, is indicative of initiationof a fault. This guide describes commonly found particles inin-service lubricants, but does not address methodology forquantification of particle concentration.5.2 This guide is provided
36、 to promote improved and ex-panded use of particulate debris analysis with in-serviceD7684 113lubricant analysis. It helps overcome some perceived complex-ity and resulting intimidation that effectively limits particulatedebris analysis to the hands of a specialized and very limitednumber of practit
37、ioners. Standardized terminology and com-mon reporting formats provide consistent interpretation andgeneral understanding.5.3 Without particulate debris analysis, in-service lubricantanalysis results often fall short of concluding likely root causeor potential severity from analytical results becaus
38、e of missinginformation about the possible identification or extent ofdamaging mechanisms.5.4 Caution shall be exercised when drawing conclusionsfrom the particles found in a particular sample, especially if thesample being examined is the first from that type of machine.Some machines, during normal
39、 operation, generate wear par-ticles that would be considered highly abnormal in othermachines. For example, many gear boxes generate severe wearparticles throughout their expected service life, whereas just afew severe wear particles from an aircraft gas turbine oilsample may be highly abnormal. So
40、und diagnostics requirethat a baseline, or typical wear particle signature, be estab-lished for each machine type under surveillance.6. Reagents6.1 Use reagents of type and purity following specificationsfrom the manufacturer of the wear debris analysis samplepreparation apparatus. Use reagents and
41、solvents that do notcontribute significant particles to the sample.7. Procedure7.1 Particulate matter extracted from in-service lubricantsare displayed on a relatively flat surface such as a filter patch,glass slide, or other substrate for microscopic inspection. Theprocedure normally involves the f
42、ollowing steps. These stepsmay be performed in this order or in a different order, and stepsmay be added as needed. This guide applies to interpretingmicroscopic observations (7.1.6) and reporting results (7.1.7)but does not address steps 7.1.1-7.1.5.7.1.1 Collecting or concentrating particulate mat
43、ter,7.1.2 Depositing it on a surface to produce a specimensuitable for placement on an optical microscope stage,7.1.3 Removing residual in-service lubricant fluid from thespecimen,7.1.4 Transporting the specimen to a microscope stage,7.1.5 Using the microscope to inspect the specimen,7.1.6 Interpret
44、ing observations, and7.1.7 Recording results.7.2 Use a desired particulate extraction technique to preparea specimen for microscopic wear debris analysis. Specimensare prepared using an apparatus that effectively extracts solidparticles from liquid samples and deposits the particles on arelatively f
45、lat supporting surface that can be placed on theviewing stage of an optical microscope.7.3 Prepare specimens using one of the following particleextraction techniques:7.3.1 Analytical ferrography using ferrograph to producelinear glass slides in accordance with Practice D7690,7.3.2 Analytical ferrogr
46、aphy using ferrograph to producedrotary glass slides,7.3.3 Filter patch analysis using filter patch makers,7.3.4 Filter debris analysis,7.3.5 Magnetic plug inspection, or7.3.6 Other means used to extract and inspect particulatedebris from in-service lubricants.7.4 Inspect the specimen using an optic
47、al microscope andclassify particles using the following procedures. It is commonfor a single specimen to carry multiple kinds of particles soclassification is normally done for a group of particles bycharacterizing individual particles representative of that group.7.5 Therefore, the first step when
48、inspecting a specimennormally involves scanning the entire specimen to identifyparticle types that are of interest by group. Next, each group ischaracterized in a logical sequence. An atlas of exampleimages is typically used to provide consistency and to assistwith cross-training between operators.
49、One such atlas isdescribed in the Wear Particle Atlas.47.6 For each group of particles the user should applyconsistent characterization criteria. Two example approachesare given below in 7.7 and 7.8 that outline processes andformat for analyzing and recording wear debris analysisclassification findings.7.7 For the first example of a particle classification ap-proach, see Table 1, which shows a tabular grid a user mayconstruct to guide inspection and documentation of wear debrisanalysis findings from a specimen. This kind of tabular gridmay be printed o
