1、Designation: G211 14Standard Test Method forConducting Elevated Temperature Erosion Tests by SolidParticle Impingement Using Gas Jets1This standard is issued under the fixed designation G211; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last 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 test method is concerned with the determination ofmaterial loss by gas-entrained solid parti
3、cle impingementerosion with jet nozzle type erosion equipment. This testmethod can be used in the laboratory to measure the solidparticle erosion of different materials and has been used as ascreening test for ranking solid particle erosion rates ofmaterials in simulated service environments. Erosio
4、n servicetakes place under conditions where particle sizes, chemistry,microstructure, velocity, attack angles, temperature,environments, etc., vary over a wide range. Hence, any singlelaboratory test may not be sufficient to evaluate expectedservice performance. This test method describes one wellch
5、aracterized procedure for solid particle impingement erosionmeasurement for which interlaboratory test results are avail-able from multiple laboratories.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does
6、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 Standa
7、rds:2B822 Test Method for Particle Size Distribution of MetalPowders and Related Compounds by Light ScatteringE122 Practice for Calculating Sample Size to Estimate, WithSpecified Precision, the Average for a Characteristic of aLot or ProcessE177 Practice for Use of the Terms Precision and Bias inAST
8、M Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1601 Practice for Conducting an Interlaboratory Study toEvaluate the Performance of an Analytical MethodE1617 Practice for Reporting Particle Size CharacterizationDataG40 Terminology Relati
9、ng to Wear and ErosionG76 Test Method for Conducting Erosion Tests by SolidParticle Impingement Using Gas Jets2.2 American National Standard:3ANSI B74.10 Grading of Abrasive Microgrits2.3 Japanese Industrial Standard:4JIS 6001 Bonded Abrasive Grain Sizes3. Terminology3.1 Definitions:3.1.1 erosionpro
10、gressive loss of original material from asolid surface due to mechanical interaction between thatsurface and a fluid, a multicomponent fluid, or impinging liquidor solid particles.3.1.2 impingementa process resulting in a continuingsuccession of impacts between (liquid or solid) particles and asolid
11、 surface.3.1.3 interlaboratory study (ILS)study undertaken to as-certain if a test method is suitable for its intended use. The ILSincludes preparation, testing, and evaluation phases.3.2 Definitions of Terms Specific to This Standard:3.2.1 mass loss erosion ratethe mass loss of specimenmaterial div
12、ided by the total mass of erodent particles thatimpacted the specimen (milligrams of specimen material loss /gram of erodent impacting the specimen).4. Summary of Test Method4.1 This test method utilizes a repeated impact erosionapproach involving a small nozzle delivering a stream of gas1This test
13、method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.10 on Erosion bySolids and Liquids.Current edition approved July 15, 2014. Published August 2014. DOI: 10.1520/G0211-14.2For referenced ASTM standards, visit the ASTM websit
14、e, 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 American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/
15、www.ansi.org.4Available from Japanese Standards Organization (JSA), 4-1-24 AkasakaMinato-Ku, Tokyo 107-8440, Japan, http:/www.jsa.or.jp.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1containing erodent particles which impacts the sur
16、face of a testspecimen at elevated temperatures. A standard set of testconditions is described. However, deviations from some of thestandard conditions are permitted if described thoroughly. Thisallows for laboratory scale erosion measurements under arange of conditions. Test methods are described f
17、or preparingthe specimens, conducting the erosion exposure, and reportingthe results.5. Significance and Use5.1 The significance of this test method in any overallmeasurements program to assess the erosion behavior ofmaterials will depend on many factors concerning the condi-tions of service applica
18、tions. The users of this test methodshould determine the degree of correlation of the resultsobtained with those from field performance or results usingother test systems and methods. This test method may be usedto rank the erosion resistance of materials under the specifiedconditions of testing.6.
19、Apparatus6.1 The apparatus is capable of eroding material from a testspecimen under well controlled exposure conditions. A sche-matic drawing of the exit nozzle and the particle-gas supplysystem is shown in Fig. 1. Deviations from this design arepermitted; however, adequate system characterization a
20、ndcontrol of critical parameters are required. Nozzle design anddimensions must be documented. Nozzle length to diameterratio should be 25:1 or greater in order to achieve an acceptableparticle velocity distribution in the stream.6.2 Necessary features of the apparatus shall include ameans of contro
21、lling, measuring, and adjusting the (a) particleimpact velocity, (b) particle feed rate, (c) the specimen standoffdistance, (d) angular orientation of sample relative to theimpinging stream, and (e) gas stream and test specimentemperature.6.3 Various means can be provided for introducing particlesin
22、to the gas stream, including a vibrator-controlled hopper or ascrew-feed system. It is required that the system provide auniform particle feed and that it be adjustable to accommodatedesired particle flow values. The total amount of erodentimpinging the specimen is to be recorded. Depending on thefe
23、ed system, the feeding rate may be determined by differentmethods. If a tank reservoir is used, the tank weight may bemeasured by weighting both before and after the single test ora given time duration.Also, the applied dose may be calculatedby measuring the time duration. Verification and qualifica
24、tionof constant feed rate should be established by initial trials.6.4 A method to measure the particle velocity shall beavailable for use with the erosion equipment. The mass erosionrate is highly dependent on particle velocity as shown in thepower law equation (Eq 1).NOTE 1The erosion rig orientati
25、on may vary and does not affect the test results.FIG. 1 Schematic Drawing of Solid Particle Erosion Test SystemG211 1426.4.1 The relationship of erosion rate (E) and impact veloc-ity (v) can often be described by an equation of the form:E 5 kvm(1)where k is a constant and m is the velocity exponent
26、whichis approximately equal to two (parabolic behavior). If E ismeasured from experiments, v may be calculated from equa-tions provided in Figs. X3.1-X3.3 to cross-check the mea-sured velocities in the experiments.6.5 Examples of accepted methods to measure the particlevelocity are high-speed photog
27、raphy, double rotating disk(DRD), laser Doppler velocimetry (LDV), and particle imagevelocimetry (PIV). Particle velocity shall be measured at thelocation to be occupied by the specimen and under theconditions of the test. Examples of the double rotating disc aredescribed in Appendix X1.7. Test Mate
28、rials and Sampling7.1 This test method can be used over a range of specimensizes and configurations. One convenient specimen configura-tion is a rectangular strip approximately 25 by 75 by 3 mmthick. Larger specimens and other shapes can be used wherenecessary, but must be documented. It is critical
29、 that all of theparticles impinge the test specimen. Overspray outside of thetest specimens is not permitted.7.2 For the reference tests Type 410 stainless steel asdescribed in 8.2.4 shall be used with the alumina erodentspecified. Other erodent materials, if used after the referencetesting is compl
30、ete, shall be uniform in essential characteristicssuch as particle size, moisture, chemical composition,hardness, the friability of the erodent, reactivity with carriergas and test material, modulus of the erodent at temperature oftest, etc. Erodent particle size distribution (PSD) and particlemorph
31、ology shall be documented for each new powder lotused. Light scattering powder size determination methods havebeen demonstrated to be an effective way to document the PSDof each erodent batch. Reporting the PSD as D10, D50, andD90 diameters has been found useful. Practices B822 andE1617 should be co
32、nsulted.7.3 Sampling of material for the purpose of obtainingrepresentative test specimens shall be done in accordance withacceptable statistical practice. Practice E122 shall be consulted.8. Test Condition and Test Procedure8.1 Test Conditions:8.1.1 The following conditions summarized in Table 1 ar
33、erecommended which were used during the ILS study. Note thateach high-temperature erosion rig used in this study is uniquein design and operational variables. Each one of the employeddifferent nozzle diameters, sample stand-off distance, particlefeed mechanism, velocity measurement method, etc.8.2 T
34、est Procedure:8.2.1 The inside diameter of the erodent delivery nozzleshall be a minimum of 4 mm. Measure the nozzle insidediameter at or within 1 mm from the exit end to an accuracy of0.05 mm before the start of the tests and record the measure-ments. Measure and record the diameter after completin
35、g testson a single specimen, that is, after five runs on the same testcoupon. Calibrated pins, optical methods, or direct measure-ments using precision calipers may be employed for suchmeasurements.8.2.2 The test gas shall be nominally dry air with a dewpoint of -50C or lower. Record the amount of w
36、ater present inthe test gas in the test report.8.2.3 Prepare the specimen surface if required to achieveuniformity and adequate finish. Grinding through a series ofabrasive papers to 400 grit is usually adequate so long as allsurface scale is removed. Clean the specimen surface carefullywith a non-c
37、orrosive cleaning agent such as ethanol, acetone,etc., and air dry. Important considerations in cleaning includesurface oils or greases, surface rust or corrosion, adheringabrasive particles, etc. A surface roughness of 0.2 m Ra orbetter is recommended. Weigh on an analytical balance to anaccuracy o
38、f 60.1 mg (60.0001 g).8.2.4 For the reference tests, use Type 410 Stainless Steelconforming to the characteristics shown in Tables 2 and 3 andFig. 2. The specimen dimensions are 75 by 25 by 4.5 mm.Other dimensions may be used; record dimensions to anaccuracy of 60.5 mm.The thickness of the specimen
39、should belarge enough that bending of the specimen should not occurdue to residual stress effects, after the erosion tests.8.2.5 The erodent particles used shall be nominal 50-mangular Al2O3, conforming to the JIS 6001 320 microgritstandard and equivalent to those used in the interlaboratory testser
40、ies (see Figs. 3 and 4). Record the particle size distributionas shown in the note below (Note 1). The erodent shall be usedonly once.NOTE 1Typical size distribution D10 34 m, D50 50 m, D90 75 m (see Fig. 4).8.2.6 Fix the angle between the nozzle axis and the speci-men surface at 90 6 2 and 30 6 2.
41、Other angles may be usedif needed with the same set-up accuracy.8.2.7 The particle feed rate shall be 2.0 6 0.5 gmin-1.Adjust the controls to deliver this feed rate (Note 2).NOTE 2Particles may be collected by directing the flow from thenozzle into a large vented container. Care must be taken to avo
42、id causingany significant back pressure on the nozzle as this will disturb the systemflow conditions.8.2.8 For the room temperature (RT) tests the normalambient value (typically between 18 to 28C) and for thehigh-temperature (HT) tests it shall be 600 6 5C. For theinitial calibration of the apparatu
43、s, measure the test specimentemperature using a thermocouple in contact with the speci-men. Adjust the heating controls to achieve the desiredtemperature. Perform this temperature calibration before andafter a series of tests. Record the temperatures on the test datarecord sheet. Note any deviations
44、 during the test in thetemperature of the carrier gas if heated gas is used or thetemperature of the specimen chamber if a heating enclosure isused.8.2.9 The erodent particle velocity shall be 200 6 10 ms-1.measure the velocity at the specimen location. Report thevelocity measurement method used and
45、 the accuracy (scatterband) of the measurements (Note 3).NOTE 3The ILS study was conducted at 200 m/s. However, this testG211 143procedure is applicable to other particle velocities. Plots shown in Figs. X3.1-X3.3 may be used to calibrate the test system.TABLE 1 Round-Robin Erosion Testing Requireme
46、nts for the ILS StudyG211 1448.2.10 Adjust the distance from specimen surface to thenozzle tip to achieve an erosion scar diameter of approximately14 mm at 90 and the minor axis of the ellipse at 30.As shownin Fig. 5 schematic and on tested specimens. Figs. X2.4 andX2.5 in Appendix X2 illustrate how
47、 to determine the boundaryof the erosion scar.8.2.11 Conduct the erosion tests as a series of five 10 mintest interval exposures on the same specimen at the same spot.Take the specimen out of the test chamber, clean the specimensby blowing compressed air and weigh the specimens at the startand end o
48、f each test interval. Repeat these steps after each 10min or 20 g dose for a total exposure of 100 g of the erodent.Determine the total erodent dose to an accuracy of 61 g andrecord. Report the dose of the erodent for each interval and thefinal total dose for each specimen.8.2.12 Reposition the test
49、 specimen after each intermittentweight measurement, accurately at the same spot. If you usespecially designed fixtures to hold the test specimens in the testchamber, maintain an accuracy of position of the central pointof the wear scar within 60.1 mm (0.004 in.).9. Report9.1 The test report shall include the following information:9.1.1 Material IdentificationType, chemical specification,heat and processing treatment, hardness, and density.9.1.2 SpecimensMethod of preparing and cleansingspecimens, initial surface roughness, and number tested.9.1.3 Er
