ASTM D5706-23

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D5706 − 16 D5706 − 23
Standard Test Method for
Determining Extreme Pressure Properties of Lubricating
Greases Using a High-Frequency, Linear-Oscillation (SRV)
Test Machine
This standard is issued under the fixed designation D5706; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method covers a procedure for determining extreme pressure properties of lubricating greases under high-frequency
linear-oscillation motion using the SRV test machine. This test method can also be used for evaluating extreme pressure properties
of lubricating fluid.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A295/A295M Specification for High-Carbon Anti-Friction Bearing Steel
D217 Test Methods for Cone Penetration of Lubricating Grease
D235 Specification for Mineral Spirits (Petroleum Spirits) (Hydrocarbon Dry Cleaning Solvent)
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D6425 Test Method for Measuring Friction and Wear Properties of Extreme Pressure (EP) Lubricating Oils Using SRV Test
Machine
D7421 Test Method for Determining Extreme Pressure Properties of Lubricating Oils Using High-Frequency, Linear-Oscillation
(SRV) Test Machine
E45 Test Methods for Determining the Inclusion Content of Steel
G40 Terminology Relating to Wear and Erosion
2.2 Other Standards:
DIN 51631:1999 Mineral spirits, special boiling point spirits; requirements
DIN EN ISO 683-17 Heat-treated Steels, alloy steels and free-cutting steels—Part 17 : Ball and roller bearing steels
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.G0.04 on Functional Tests - Tribology.
Current edition approved Nov. 15, 2016Dec. 1, 2023. Published February 2017January 2024. Originally approved in 1995. Last previous edition approved in 20112016
as D5706 – 11.D5706 – 16. DOI: 10.1520/D5706-16.10.1520/D5706-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from Deutsches Institut fur Normung e.V.(DIN), Burggrafenstrasse 6, 10787 Berlin, Germany, http://www.din.de.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5706 − 23
DIN EN ISO 13565-2:1998 Geometrical Product Specifications (GPS)—Surface texture: Profile method; Surfaces having
stratified functional properties—Part 2: Height characterization using linear material ratio curve [Replaces DIN 4776:1990:
Measurement of surface roughness; parameters R , R , R , M , M for the description of the material portion]
K PK VK r1 r2
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
3.1.2 break-in, n—in tribology, an initial transition process occurring in newly established wearing contacts, often accompanied
by transients in coefficient of friction or wear rate, or both, which are uncharacteristic of the given tribological system’s long-term
behavior. G40
3.1.3 coeffıcient of friction, μ or f, n—in tribology, the dimensionless ratio of the friction force (F) between two bodies to the
normal force (N) pressing these bodies together. G40
3.1.4 Hertzian contact area, n—the apparent area of contact between two nonconforming solid bodies pressed against each other,
as calculated from Hertz’s equations of elastic deformation. G40
3.1.5 Hertzian contact pressure, n—magnitude of the pressure at any specified location in a Hertzian contact area, as calculated
from Hertz’s equations of elastic deformation. The Hertzian contact pressure can also be calculated and reported as maximum value
P in the centre of the contact or as P as average over the total contact area. D7421
max average
3.1.6 lubricant, n—any material interposed between two surfaces that reduces the friction or wear, or both, between them. D4175
3.1.7 lubricating grease, n—a semi-fluid to solid product of a dispersion of a thickener in a liquid lubricant. D217
3.1.7.1 Discussion—
The dispersion of the thickener forms a two-phase system and immobilizes the liquid lubricant by surface tension and other
physical forces. Other ingredients are commonly included to impart special properties.
3.1.8 thickener, n—in lubricating grease, a substance composed of finely divided solid particles dispersed in a liquid lubricant to
form the grease structure. D217
3.1.8.1 Discussion—
The thickener can be fibers (such as various metallic soaps) or plates or spheres (such as certain non-soap thickeners) which are
insoluble or, at most, only very slightly soluble in the liquid lubricant. The general requirements are that the solid particles be
extremely small, uniformly dispersed, and capable of forming a relatively stable, gel-like structure with the liquid lubricant.
3.1.9 Ra (C.L.A.), n—in measuring surface finish, the arithmetic average of the absolute distances of all profile points from the
mean line for a given distance.
3.1.9.1 Discussion—
C.L.A. means center line average, and it is a synonym for Ra.
3.1.10 Rpk, n—reduced peak height according to DIN EN ISO 13565-2:1998. Rpk is the mean height of the peak sticking out
above the core profile section.
3.1.11 Rvk, n—reduced valley height according to DIN EN ISO 13565-2:1998. Rvk is the mean depth of the valley reaching into
the material below the core profile section.
3.1.12 Rz (DIN), n—in measuring surface finish, the average of all Ry values (peak to valley heights) in the assessment length.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 extreme pressure, adj—in lubrication—characterized by metal surfaces in contact under high-stress rubbing conditions.
Amstutz, Hu, “Surface Texture: The Parameters,” Bulletin MI-TP-003-0785, Sheffield Measurement Division, Warner and Swasey, 1985, p. 21.
Amstutz, Hu, “Surface Texture: The Parameters,” Bulletin MI-TP-003-0785, Sheffield Measurement Division, Warner and Swasey, 1985, pp. 29, 31.
D5706 − 23
FIG. 1 SRV Test Machine, Model III
3.2.2 seizure, n—localized fusion of metal between the rubbing surfaces of the test pieces.
3.2.2.1 Discussion—
In this test method, seizure is indicated by a sharp rise in the coefficient of friction, over steady state, of greater than 0.20.1 for
over 20 s. s in combination with associated changes in the stroke signal of greater than 610 % (see 9.12 and Appendix X1 for
more detailed information). In severe cases, a stoppage in the motor will occur.
3.3 Abbreviations:
3.3.1 SRV, n—Schwingung, Reibung, Verschleiss (German); oscillating, friction, wear (English translation).
4. Summary of Test Method
4.1 This test method is performed on an SRV test machine using a steel test ball oscillating against a stationary steel test disk with
lubricant between them. Test load is increased in 100 N increments until seizure occurs. The load, immediately prior to the load
at which seizure occurs, is measured and reported.
NOTE 1—Test frequency, stroke length, temperature, and ball and disk material can be varied to simulate field conditions. The test ball yields point-contact
geometry. To obtain line or area contact, test pieces of differing configurations can be substituted for the test balls.
5. Significance and Use
5.1 This laboratory test method can be used to quickly determine extreme pressure properties of lubricating greases at selected
temperatures specified for use in applications where high-speed vibrational or start-stop motions are present with high Hertzian
point contact. This test method has found wide application in qualifying lubricating greases used in constant velocity joints of
front-wheel-drive automobiles. Users of this test method should determine whether results correlate with field performance or other
applications.
6. Apparatus
6.1 SRV Test Machines, illustrated in Figs. 1-4.
7. Reagents and Materials
7.1 Test Ball, 52100 steel, Rockwell Vickers micro-hardness of 660 HV0.2 to 730 HV0.2 (Rockwell hardness number of 60 HRC
6 2 HRC,2 HRC), 0.025 μm 6 0.005 μm Ra surface finish, 10 mm diameter.
The sole source of supply of the apparatus known to the committee at this time is Optimol Instruments Prüftechnik GmbH, Westendstrasse 125, D-80339,GmbH,
Flößergasse 3, D-81639, Munich Germany, http://www.optimol-instruments.de. If you are aware of alternative suppliers, please provide this information to ASTM
International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend.
D5706 − 23
1. Oscillation drive rod 6. Electrical resistance heater
2. Test ball holder 7. Resistance thermometer
3. Load rod 8. Test disk holder
4. Test ball 9. Piezoelectric measuring device
5. Test disk 10. Receiving block
FIG. 2 Test Chamber Elements of SRV III
FIG. 3 SRV Test Machine, Model IV
7.2 Lower Test Disk, vacuum arc remelted (VAR) AISI 52100 steel with an inclusion rating using Method D, Type A, as severity
level number of 0.5 according to Test Methods E45 and Specification A295/A295M or an inclusion sum value K1 ≤ 10 according
to DIN EN ISO 683-17 and spherodized annealed to obtain globular carbide, Rockwell Vickers micro-hardness of 660 HV0.2 to
730 HV0.2 (Rockwell hardness number of 60 HRC 6 2 HRC,2 HRC), the surfaces of the disk being lapped and free of lapping
raw materials. The topography of the disk will be determined by four values, 24 mm diameter by 7.85 mm 7.850 mm 6 0.100 mm
thick:
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1. Base of the receiving block 7. Upper specimen holder
2. Piezo force measuring elements 8. Drive rods of the load unit
3. Supporting surface (head plate) of the 9. Test disk
receiving block
4. Lower specimen holder 10. Test ball
5. Position of the electrical resistance heating F Normal force (test load)
n
resistance thermometer
6. Oscillation drive rods F Friction force
f
FIG. 4 Test Chamber Elements of SRV Models IV and V
0.5 μm 0.500 μm < Rz (DIN) < 0.650 μm
0.035 μm 0.035 μm < Ra (C.L.A.) < 0.050 μm
0.020 μm 0.020 μm < Rpk < 0.035 μm
0.050 μm 0.050 μm < Rvk < 0.075 μm
NOTE 2—The DIN 17230-1980 was replaced by DIN EN ISO 683-17.
7.3 n-Heptane, reagent grade. (Warning—Flammable. Health hazard.)
7.4 Isopropanol, reagent grade. (Warning—Flammable. Health hazard.)
7.5 Toluene, reagent grade. (Warning—Flammable. Health hazard)
7.3 Cleaning Solvent, the test disks have to be cleaned by a liquid solvent (non-chlorinated, non-film forming). The cleaning
solvent can be either a mixture of equal volumes of n-heptane, isopropanol, and toluene, all as reagent grades (Warning—
Flammable. Health hazard.) or a single boiling point spirit type 2 according to DIN 51631:1999 published in English
(Warning—Flammable. Health hazard.)
NOTE 3—It is recommended to use a mixture of equal volumes In the case of unavailability of nDIN-heptane, isopropanol, and toluene, all as 51631:1999,
please refer to Specification D235reagent grades. ( – 12 regarding TypeWarning—Flammable. Health hazard.) I, Class C (with less than 2 % by volume
of aromatics), mineral spirits.
8. Preparation of Apparatus
Preparation of SRV I and II Models
8.1 Turn on the test machine and chart recorder and allow to warm up warm-up for 15 min prior to running tests.
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TABLE 1 Pass Load according to Procedure B in Test Method D5706 of Different Greases using Δx = 1.5 mm stroke at 80 °C
NOTE 1—The repeatability and the reproducibility were calculated using ADJD6300 (D2PP software).
NOTE 2—With a mean of ~1.100 N, it is not clear that seizures occurred using machines with a highest load of 1200 N.
Year RR2003 RR2002 RR2001 RR2003 RR2002 RR2001
Test greases, Test Li/Ca- Li/Ca- Li/Ca- PAO PAO PAO
Method D5706 12-OH-Stearat 12-OH-Stearat 12-OH-Stearat Polybuten-bentonit Polybuten- bentonit Polybuten/- Bentonit
Modifications Δx = 1.5 mm, Δx = 1.5 mm, Δx = 1.5 mm Δx = 1.5 mm, Δx = 1.5 mm, Δx = 1.5 mm
grease apply caliper, grease apply caliper grease apply caliper, grease apply caliper
O.K.- load O.K.- load
Statistical Quantities Highest test load [N] Highest test load [N] Highest test load [N] Highest test load [N] Highest test load [N] Highest test load [N]
Number of Results 33 50 56 38 53 54
Degree of freedom 22 28 30 33 27 39
Mean 1088 1180 1028 434 486 505
Standard deviation ±247 ±235 ±217 ±71.1 ±129 ±106
Reproducibility, R 726 680 627 205 374 303
Repeatability, r 265 267 219 173 201 197
8.2 Select the friction data to be presented in the crest peak value position in accordance with the manufacturer’s directions.
NOTE 4—In most cases, this is accomplished by positioning the sliding switch on electronic card NO. 291.35.20E (front side of electronics behind the
front panel) and the sliding switch located on the back panel of the control unit.
8.3 Turn the amplitude knob to ZERO.
8.4 Switch the stroke adjustment to AUTO position.
8.5 Set the frequency to 50 Hz.50 Hz.
8.6 Set as a ramp function with a gradient of 7.5 N ⁄s.
8.7 Set the desired span and calibrate the chart recorder in accordance with the manufacturer’s instructions. Select the desired chart
speed.
8.8 Turn on the heater control, and preheat the disk holder to the desired temperature. 50 °C, 80 °C, and 120 °C are recommended
(see Table 1). When the temperature has stabilized, turn on the chart recorder and depress the drive start toggle switch until the
timer begins to count and then adjust the stroke amplitude knob to 2.00 mm.1.50 mm.
8.9 Set the load charge amplifier to setting that corresponds to the 400 N load.
8.10 Change the load charge amplifier at each load in accordance with the manufacturer’s instructions when the coefficient of
friction at each test load is to be studied.
8.11 When the digital timer reaches 30 s, increase the load to 100 N using the slow ramp speed rate, and maintain this load for
15 min.
8.12 The 15 min interval includes the loading ramp sequence. The load has to be increased by 100 N every 2 min using the slow
ramp until a load of 1200 N is reached, or the load limit of the test apparatus is attained, or failure occurs. Failure is indicated by
a rise in coefficient of friction of greater than 0.20.1 over steady state for over 20 s or a stoppage in the oscillating of the test
machine (see Test Method machine.D5706 or D6425.
NOTE 5—Because a 30 s break-in at 50 N is used, the load increase times will occur on the half minute of even minutes.
D5706 − 23
8.13 When the 1200 N load run or maximum load of the test apparatus is completed or failure occurs, turn off the heater control,
release the load to minimum setting, (typically –13 N or –14 N), and remove the test ball, disk, and lubricating oil test specimen.
Preparation of SRV III, IV, and V4, and 5 Models
8.14 When using SRV III, SRV IV,4, and SRV V5 models, clean and install the specimens as specified under 9.1 to 9.7. Turn on
the test machine and the PC and allow to warm up for 15 min prior to running tests.
8.15 Create a set point profile in the SRVSRV® control software with the following parameters:
NOTE 6—Depending on the software version, names and availability of the parameters can vary.
8.15.1 Start conditions (thermostatic stabilization):
Temperature: for example, 50 °C ± 1 K or 80 °C ± 1 K
Temperature: for example, 50 °C ± 1°C or 80 °C ± 1 °C
Test load: 50 N ± 1 N
Start delay: 300 s (is displayed by all versions of the SRV software)
8.15.2 Cut-off criteria for friction, if occurs:
Coefficient of friction, f (cut-off value for permanent increase of level):
0.3 during t > 20 s
Coefficient of friction, f (cut-off value for permanent increase of level):
0.1 during t > 20 s
Coefficient of friction, f (cut-off value for one-off increase of level): 0.35
8.15.3 Test parameters:
Frequency: 50 Hz
Stroke: 1.00 mm for procedure A with 2 min run-in; 1.50 mm for procedure B with 15 min run-in
Stroke: 1.00 mm for procedure A; 1.50 mm for procedure B
Temperature: for example, 50 °C or 80 °C
Pre-load: 50 N for 30 s
Set as a load ramp function with a gradient of 7.5 N ⁄s
Test load: running-in under 100 N for 15 min, then steps of 100 N with a
duration of 2 min until the maximum test load (usually 2000 N) has
been reached.
Test load: running-in under 100 N for 15 min, then steps of 100 N with a
duration of 2 min until the maximum test load (usually 2000 N) has
been reached.
Total test duration: up to 53.5 min
NOTE 7—Because a 30 s break-in at 50 N is used, the load increase times will occur on the half minute of even minutes.
NOTE 8—For optimal comparability with older SRV models I and II, the test load should be set as a ramp function with a gradient of 7.5 N ⁄s.
8.15.4 Sample rates for result-relevant measuremen
...