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Designation: G 76 – 95

Standard Test Method for

Conducting Erosion Tests by Solid Particle Impingement
Using Gas Jets1
This standard is issued under the fixed designation G 76; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope succession of impacts between (liquid or solid) particles and a

1.1 This test method covers the determination of material solid surface.
loss by gas-entrained solid particle impingement erosion with 3.2 Definitions of Terms Specific to This Standard:
jetnozzle type erosion equipment. This test method may be 3.2.1 erosion value—the volume loss of specimen material
used in the laboratory to measure the solid particle erosion of divided by the total mass of abrasive particles that impacted the
different materials and has been used as a screening test for specimen (mm3·g−1).
ranking solid particle erosion rates of materials in simulated 3.2.2 Normalized Erosion Rate—erosion value (mm3·g−1)
service environments (1, 2).2 Actual erosion service involves of specimen material divided by erosion value (mm3·g−1) of
particle sizes, velocities, attack angles, environments, etc., that reference material.
will vary over a wide range (3-5). Hence, any single laboratory
4. Summary of Practice
test may not be sufficient to evaluate expected service perfor-
mance. This test method describes one well characterized 4.1 This test method utilizes a repeated impact erosion
procedure for solid particle impingement erosion measurement approach involving a small nozzle delivering a stream of gas

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for which interlaboratory test results are available. containing abrasive particles which impacts the surface of a
1.2 This standard does not purport to address all of the test specimen. A standard set of test conditions is described.
However, deviations from some of the standard conditions are
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safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- permitted if described thoroughly. This allows for laboratory
priate safety and health practices and determine the applica- scale erosion measurements under a range of conditions.
bility of regulatory limitations prior to use.
2. Referenced Documents
Document Preview Methods are described for preparing the specimens, conducting
the erosion exposure, and reporting the results.
5. Significance and Use
2.1 ASTM Standards:
E 122 Practice for Choice of Sample Size to Estimate a ASTM G76-95
5.1 The significance of this test method in any overall
Measure https://standards.iteh.ai/catalog/standards/sist/12fb5de3-277e-4bc6-8f70-22611848b855/astm-g76-95
of Quality for a Lot or Process 3 measurements program to assess the erosion behavior of
G 40 Terminology Relating to Wear and Erosion 4 materials will depend on many factors concerning the condi-
2.2 American National Standard: tions of service applications. The users of this test method
ANSI B74.10 Grading of Abrasive Microgrits 5 should determine the degree of correlation of the results
obtained with those from field performance or results using
3. Terminology other test systems and methods. This test method may be used
3.1 Definitions: to rank the erosion resistance of materials under the specified
3.1.1 erosion—progressive loss of original material from a conditions of testing.
solid surface due to mechanical interaction between that
6. Apparatus 6
surface and a fluid, a multicomponent fluid, or impinging liquid
or solid particles. 6.1 The apparatus is capable of eroding material from a test
3.1.2 impingement—a process resulting in a continuing specimen under well controlled exposure conditions. A sche-
matic drawing of the exit nozzle and the particle-gas supply
1
system is shown in Fig. 1. Deviations from this design are
This practice is under the jurisdiction of ASTM Committee G-2 on Wear and permitted; however, adequate system characterization and
Erosion and is the direct responsibility of Subcommittee G02.10 on Erosion by
Solids and Liquids. control of critical parameters are required. Deviations in nozzle
Current edition approved Feb. 15, 1995. Published April 1995. Originally design and dimensions must be documented. Nozzle length to
published as G 76 – 83. Last previous edition G 76 – 83 (1989)e1. diameter ratio should be 25:1 or greater in order to achieve an
2
Boldface numbers in parentheses refer to references at the end of this practice.
3
Annual Book of ASTM Standards, Vol 14.02.
4
Annual Book of ASTM Standards, Vol 03.02.
5 6
Available from American National Standards Institute, 11 West 42nd Street, A commercial apparatus is available from Falex Corp., 1020 Airpark Dr., Sugar
13th Floor, New York, NY 10036. Grove, IL 60554.

Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

1
 G 76
TABLE 1 Characteristics of Type 1020 Steel Reference Material
Annealed 15 min at 760°C (1400°F), air cooled.
Hardness: HRB 5 706 2.

Chemical Composition:
C 5 0.20 6 0.01 wt %
Mn 5 0.45 6 0.10
S 5 0.03 6 0.01
Si 5 0.16 0.05
P 5 0.01 6 0.01

FIG. 1 Schematic Drawing of Solid Particle Erosion Equipment

acceptable particle velocity distribution in the stream. The

recommended nozzle7 consists of a tube about 1.5 mm inner
diameter, 50 mm long, manufactured from an erosion resistant
material such as WC, A12O3, etc. Erosion of the nozzle during
service shall be monitored and shall not exceed 10 % increase
in the initial diameter.
6.2 Necessary features of the apparatus shall include a
means of controlling and adjusting the particle impact velocity,
particle flux, and the specimen location and orientation relative
to the impinging stream.
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6.3 Various means can be provided for introducing particles
into the gas stream, including a vibrator-controlled hopper or a

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screw-feed system. It is required that the system provide a
uniform particle feed and that it be adjustable to accommodate
desired particle flow values.
Document Preview
6.4 A method to measure the particle velocity shall be
available for use with the erosion equipment. Examples of FIG. 2 Microstructure of 1020 Steel Reference Material
accepted methods are high-speed photography (6), rotating ASTM Grain Size 9
double-disk (7), and laser velocimeter (8). Particle velocity ASTM G76-95
shall be measured at the location to be occupied by the series8 shall be tested periodically using specified (see Section
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specimen and under the conditions of the test. 9) 50 µm A12O3 particles to verify the satisfactory performance
of the apparatus. It is recommended that performance be
7. Test Materials and Sampling verified using this reference material every 50 tests during a
7.1 This test method can be used over a range of specimen measurement series, and also at the beginning of each new test
sizes and configurations. One convenient specimen configura- series whenever the apparatus has been idle for some time. The
tion is a rectangular strip approximately 10 by 30 by 2 mm recommended composition, heat treatment, and hardness range
thick. Larger specimens and other shapes can be used where for this steel are listed in Table 1. The use of a steel of different
necessary, but must be documented. composition may lead to different erosion results. A photomi-
7.2 The abrasive material to be used shall be uniform in crograph of the specified A12O3 particles is shown in Fig. 3.
essential characteristics such as particle size, moisture, chemi- The range of erosion results to be expected for this steel under
cal composition, etc. the standard test conditions specified in Section 9 is shown in
7.3 Sampling of material for the purpose of obtaining Table 2 and is based on interlaboratory test results.8
representative test specimens shall be done in accordance with 8.2 Calibration at standard test conditions is recommended
acceptable statistical practice. Practice E 122 shall be con- even if the apparatus is operated at other test conditions.
sulted. 8.3 In any test program the particle velocity and particle
feed rate shall be measured at frequent intervals, typically
8. Calibration of Apparatus every ten tests, to ensure constancy of conditions.
8.1 Specimens fabricated from Type 1020 steel (see Table 1
and Fig. 2) equivalent to that used in the interlaboratory test 9. Standard Test Conditions
9.1 This test method defines the following standard condi-
tions.
7
A source for the recommended nozzle (tungsten carbide) is Kennametal, Inc.,
Latrobe, PA.
8
Supporting data are available from ASTM Headquarters. Request
RR:G–2–1003.