1、Designation: G75 15Standard Test Method forDetermination of Slurry Abrasivity (Miller Number) andSlurry Abrasion Response of Materials (SAR Number)1This standard is issued under the fixed designation G75; the number immediately following the designation indicates the year of originaladoption or, in
2、the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a single laboratory procedurethat can be used to develop data fr
3、om which either the relativeabrasivity of any slurry (Miller Number) or the response ofdifferent materials to the abrasivity of different slurries (SARNumber), can be determined.1.2 The test data obtained by this procedure is used tocalculate either a number related to the rate of mass loss ofduplic
4、ate standard-shaped 27 % chromium iron wear blockswhen run for a period of time in the slurry of interest (MillerNumber), or to calculate a number related to the rate of massloss (converted to volume loss) of duplicate standard-shapedwear specimens of any material of interest when run for aperiod of
5、 time in any slurry of interest (SAR Number).1.3 The requirement for a finished flat wearing surface onthe test specimen for a SAR Number test may precludeapplication of the procedure where thin (0.051 to 0.127-mm),hard, wear-resistant coatings will not allow for surface finish-ing. The 6 hours tota
6、l duration of the SAR Number Test maynot allow establishment of a consistent rate-of-mass-loss of theunfinished surface.1.4 This standard does 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-pr
7、iate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2G40 Terminology Relating to Wear and Erosion2.2 Military Standard:MIL-R-6855C Rubber, Synthetic, Sheets, Strips, Molded orExtruded Shapes33. Terminology
8、3.1 Definitions:3.1.1 Definitions used in this test method are in accordancewith Terminology G40 as follows:3.1.2 abrasive wearwear due to hard particles or hardprotuberances forced against and moving along a solid surface.3.1.3 corrosive wearwear in which chemical or electro-chemical reaction with
9、the environment is significant.3.1.4 abrasion-corrosiona synergistic process involvingboth abrasive wear and corrosion in which each of theseprocesses is affected by the simultaneous action of the otherand, in many cases is thereby accelerated.3.1.5 cumulative erosion-time curvea plot of cumulativee
10、rosion versus cumulative exposure duration, usually deter-mined by periodic interruption of the test and weighing of thespecimen. This is the primary record of an erosion test. Mostother characteristics, such as the incubation period, maximumerosion rate, terminal erosion rate, and erosion rate-time
11、 curve,are derived from it.3.1.6 erosionprogressive loss of original material from asolid surface due to mechanical interaction between thatsurface and a fluid, a multi-component fluid, or impingingliquid or solid particles.3.1.7 erosion-corrosiona conjoint action involving corro-sion and erosion in
12、 the presence of a corrosive substance.3.1.8 instantaneous erosion ratethe slope of a tangent tothe cumulative erosion-time curve at a specified point on thatcurve.3.2 Definitions of Terms Specific to This Standard:3.2.1 mass concentrationthe mass of solid particles perunit mass of mixture, expresse
13、d in percent.1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.30 on AbrasiveWear.Current edition approved Nov. 1, 2015. Published November 2015. Originallyapproved in 1982. Last previous edition approved in 2013
14、 as G7507 (2013). DOI:10.1520/G0075-15.2For 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 Standa
15、rdization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 Miller Numbera measure of slurry abrasivity asrelated to the instantane
16、ous rate of mass loss of a standardmetal wear block at a specific time on the cumulative abrasion-corrosion time curve.3.2.3 SAR Numbera measure of the relative abrasionresponse of any material in any slurry, as related to theinstantaneous rate of mass-loss of a specimen at a specific timeon the cum
17、ulative abrasion-corrosion time curve, converted tovolume or thickness loss rate.3.2.4 slurrya mixture of solid particles in liquid, of such aconsistency as to be capable of being pumped like a liquid.3.2.5 slurry abrasivitythe relative tendency of a particularmoving slurry to produce abrasive and c
18、orrosive wear com-pared with other slurries.4. Summary of Test Method4.1 The relative effect of slurry abrasivity in both the MillerNumber and the SAR Number is determined by using themeasured mass loss of a standard-shaped 27 % chrome ironmetal wear block (Miller Number); or a metal, ceramic,compos
19、ite, plastic, or elastomer wear specimen (SARNumber), driven in a reciprocating motion by a rotating crank,riding in the bottom of a trough containing the slurry. A directload is applied to the wear block or wear specimen. For eachtest, the bottom of the trough is equipped with a new piece ofa sheet
20、 of Neoprene4to act as a lap. The interior of the troughhas a flat-bottomed or truncated “V” shape trough that confinesthe slurry particles to the path taken by the wear block or wearspecimen. At one end of each stroke, the wear block wearspecimen is lifted off the lap by a cam action for sufficient
21、 timeto allow fresh slurry material to flow under the wear block orwear specimen. The wear block/wear specimen holder is madeof plastic, as are the troughs, so that electrolysis inherent incertain slurries is minimized.4.2 The test consists of measuring the mass loss of a partthat is referred to eit
22、her a wear block or wear specimen to beconsistent with Section G34 of Form and Style for ASTMStandards. Standard wear blocks of 27 % chrome iron are usedfor the Miller Number test where the slurry is the specimen andthe results are the relative abrasivity of the slurry. Wearspecimens are used in the
23、 SAR Number test where the testresults are the relative wear rate of different wear specimens ina given slurry.4.3 This test method was originally developed as a 16-h testto be run in 4-h increments. However, experience has shownthat the extended test length is unnecessary and it has beenestablished
24、 that a 6-h test, run in 2-h increments, givesessentially equivalent results. The current revision is based onthe shorter test procedure.5. Significance and Use5.1 The Miller Number5is an index of the relative abrasiv-ity of slurries. Its primary purpose is to rank the abrasivity ofslurries in terms
25、 of the wear of a standard reference material.The wear damage on the standard wear block is worse as theMiller Number gets higher.5.2 The SAR Number is an index of the relative abrasionresponse of materials as tested in any particular slurry ofinterest. The SAR Number is a generalized form of the Mi
26、llerNumber applicable to materials other than the referencematerial used for the Miller Number determination. A majorpurpose is to rank construction materials for use in a system forpumping and fluid handling equipment for a particular slurry. Itcan also be used to rank the abrasivity of various slu
27、rriesagainst any selected construction material other than thereference material specified for a Miller Number determina-tion. The slurry damage on the specimen of material beingtested is worse as the SAR Number gets higher.5.3 Experience has shown that slurries with a Miller Num-ber or a SAR Number
28、 of approximately 50 or lower can bepumped with minor abrasive damage to the system. Above anumber of 50, precautions must be observed and greaterdamage from abrasion is to be expected. Accordingly, theMiller Number and the SAR Number provide informationabout the slurry or the material that may be u
29、seful in theselection of pumps and other equipment and to predict the lifeexpectancy of liquid-end parts of the pumps involved.5.4 The SAR Number can be used to determine the mostsuitable materials for certain slurry systems.6. Apparatus6.1 Figs. 1 and 2 show the arrangement of a typical testmachine
30、.66.2 Description of Machine:6.2.1 The drive mechanism provides a horizontal recipro-cating harmonic motion to the wear block/wear specimen armof 203.2-mm travel. The arm is freely pivoted to a crosshead ata point that results in the arm being parallel (level) to the4Neoprene is a registered tradema
31、rk of E. I. du Pont de Nemours and Co.,Wilmington, DE 19898.5“The Miller NumberA New Slurry Rating Index,” AIME Paper 73-B-300,SME Meeting, Pittsburgh, PA, 1973.6The sole source of supply of the machine and parts, including laps and wearblocks, known to the committee at this time is Falex Friction a
32、nd Wear TestMachines, 1020 Airport Dr., Sugar Grove, IL 60554. If you are aware of alternatesuppliers, please provide this information to ASTM Headquarters. Your commentswill receive careful attention at a meeting of the responsible technical committee1which you may attend.FIG. 1 Miller Number Machi
33、neG75152crosshead ways in the operating position. The crosshead isconnected to a crank, rotating at 48 r/min, by an appropriateconnecting rod.6.2.2 The apparatus includes two operating arms for anaveraging effect and as a check on the accuracy of measure-ments. It is possible to combine four arms on
34、 one machine sothat two simultaneous tests can be run.6.2.3 Each arm is loaded with a mass so that the totaldownward force on the face of the wear block or wearspecimen is 22.24 N (5 lb).6.2.4 A cam is provided on the trough cover plate tomomentarily lift each arm at the end of a stroke to a distanc
35、eof 1 mm off the rubber lap.6.2.5 Troughs about 50 mm wide by 381 mm long by 50mm high are used. A separate trough is required for each arm.6.2.6 Troughs as described above are machined into anelastomer material to form a slurry trough component that isused to hold the rubber lap in place between th
36、e bottom of thetrough and the base plate and to provide a V-shaped openbottom trough for the length of the wear block or wearspecimen travel. There is a slope of 45 at the cam end of onestroke to generate a surge or back flow of fresh slurry under thelifted wear block or wear specimen.6.2.7 A wear b
37、lock/wear specimen holder is machined fromplastic to about 50 mm by 50 mm by 12.7 mm with aheight-adjusting system and a slot to hold the wear block orwear specimen and a nonmetallic clamp-bolt to hold the wearblock or wear specimen in alignment. See Fig. 3.6.2.8 The wear block/wear specimen is moun
38、ted on the armin such a manner as to allow adjustment of the wear block orwear specimen vertically and to establish parallelism with theflat rubber lap.6.2.9 Except for the wear block or wear specimen and strokelength, dimensional tolerances of the machined parts are notcritical and the tolerances c
39、an be in the order of 0.5 % total.7. Reagents and Materials7.1 The reference material7for the Miller Number is aproprietary alloy8of the type commonly used in pipeline pumpapplications. The nominal composition of this chromium-ironwear block reference material is: Carbon-2.5 %, Manganese-1.0 %, Sili
40、cone-0.6 %, Nickel-0.25 %, Chromium-28 %, Mo-lybdenum-0.3 %, Vanadium-0.8 %, Iron-balance.7.1.1 The material is obtainable in the form of a centrifu-gally cast cylinder, approximately 183-mm outside diameter by152-mm inside diameter by 305 mm long.7.1.2 In this case the following heat-treat procedur
41、e andspecimen preparation procedure should be followed:7.1.2.1 Anneal 24 h, turn and bore, approximately 179-mmoutside diameter by 164-mm inside diameter.7.1.2.2 Heat to 1010C (1850F), 60 min.7.1.2.3 Air cool, hardness 59 to 60 HRC.7.1.2.4 Grind to approximately 178-mm outside diameter by165-mm insi
42、de diameter.7.2 Using an abrasive wheel or wire EDM, cut 25.4-mmlengths or “rings” from the cylinder. Cut the rings into 15-mmwide segments. Grind the segments to the shape shown in Fig.3.7.3 As a final finish on the wearing surface, wet grind on320-grit silicon carbide paper to a 0.8 micron surface
43、 finish.The wear specimens can be ground and resurfaced with320-grit silicon carbide paper multiply times. Reconditioningis limited to homogeneous materials and minimum thicknessthat can be retained in wear specimen holder. It is importantthat a radius leading edge be maintained.7.4 The lap is a 3.1
44、8-mm thick sheet, 57.2 mm by 362 mmlong of molded neoprene rubber specified as a ModifiedMIL-R-6855C, Class 2, Grade 80.The Durometer specificationof the Neoprene has been reduced from 80 6 5to806 3. Thepurpose of the tighter specification is to reduce variabilityobserved in the initial interlaborat
45、ory test.7.5 The SAR Number wear specimen of any selectedcandidate material is machined and ground to the shape shownin Fig. 3.7.6 Isopropyl Alcohol.8. Preparation of Apparatus8.1 The following detailed description of the setup of theapparatus for the start of the test is appropriate for thecommerci
46、ally available unit. For other apparatus the procedureshould be followed as closely as possible, particularly to ensurethe alignment required.7Specimen available from Falex Friction and Wear Test Machines, 1020 AirportDr., Sugar Grove, IL 60554. Falex is the sole source of supply known to thecommitt
47、ee at this time. If you aware of alternative suppliers, please provide thisinformation to ASTM Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.8Proprietary of Woolley Tool and Manufacturing Co., P.O. Box 3505,
48、Odessa,TX 79760.FIG. 2 Miller Number Machine Slurry Trough Cross-SectionG751538.2 Wear Block or Wear Specimen Preparation:8.2.1 Prepare duplicate wear block or wear specimens foreach test. The wear blocks, or wear specimens polished orground flat on the wearing surface, should be permanentlymarked w
49、ith an identification mark or number on one side.8.2.2 The wear block/wear specimen holders are designedto be adjustable so as to accept a wear block or wear specimenof any thickness up to about 10 mm; therefore, it is possible torework the wear blocks or wear specimens and realize manymore runs, (except, of course, for coated or plated specimens).8.2.3 The wear blocks or metallic wear specimens aredemagnetized initially so as to minimize the magnetic effects inprecision weighing and possible effects in a magnetic slurry.Place the demagnetizer pole tip against the wea
