Standard Test Method for Evaluating the Scuffing Load Capacity of Oils (FZG Visual Method)

SIGNIFICANCE AND USE
The transmission of power in many automotive and industrial applications is accomplished through the use of geared systems. At higher operating speeds it is well known that the lubricant/additive system can be a significant factor in preventing scuffing (adhesive wear) damage to gears. This test method is used to screen the scuffing load capacity of oils used to lubricate spur and helical (parallel axis) gear units.
The test method is limited by the capabilities of the equipment (test rig and gears), and the performance observed may not directly relate to scuffing performance observed with spiral bevel on hypoid gearing. It is also limited to discriminating between oils with mild EP additives or less. Lubricants containing higher levels of additives, that is, those meeting the requirements of API GL4 or GL5, generally exceed the maximum load capacity of the test rig and, therefore, cannot be distinguished for their scuffing capabilities by this test method.
SCOPE
1.1 This test method, the Forschungstelle fr Zhnrder und Getriebebau (Research Site for Gears and Transmissions) Visual Method, commonly referred to as the FZG Visual Method, is intended to measure the scuffing load capacity of oils used to lubricate hardened steel gears. Scoring, a form of abrasive wear, is also included as a failure criteria in this test method. It is primarily used to assess the resistance to scuffing of mild additive treated oils such as industrial gear oils, transmission fluids, and hydraulic fluids. High EP type oils, for example, those oils meeting the requirements of API GL-4 and GL-5, generally exceed the capacity of the test rig and, therefore, cannot be differentiated with this test method.
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.
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 health practices and determine the applicability of regulatory limitations prior to use. For specific safety information, see Section 7, Section 8, 9.2, and 9.3.1.

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ASTM D5182-97(2002)e1 - Standard Test Method for Evaluating the Scuffing Load Capacity of Oils (FZG Visual Method)
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
e1
Designation: D 5182 – 97 (Reapproved 2002)
Standard Test Method for
Evaluating the Scuffing Load Capacity of Oils (FZG Visual
Method)
This standard is issued under the fixed designation D 5182; 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.
e NOTE—Warning notes were placed in the text editorially in May 2002.
1. Scope 3.1.1 scratches—the result of mechanical removal or dis-
placement, or both, of material from a surface by the action of
1.1 This test method, the Forschungstelle für Záhnräder und
abrasive particles or protuberances sliding across the surfaces.
Getriebebau (Research Site for Gears and Transmissions)
3.1.2 abrasive wear—wear due to hard particles or hard
Visual Method, commonly referred to as the FZG Visual
protuberances forced against and moving along a solid surface.
Method, is intended to measure the scuffing load capacity of
3.1.3 adhesive wear (scuffıng)—wear due to localized bond-
oils used to lubricate hardened steel gears. Scoring, a form of
ing between contacting solid surfaces leading to material
abrasive wear, is also included as a failure criteria in this test
transfer between the two surfaces or loss from either surface.
method. It is primarily used to assess the resistance to scuffing
3.1.4 scoring—a severe form of wear characterized by the
of mild additive treated oils such as industrial gear oils,
formationofextensivegroovesandscratchesinthedirectionof
transmission fluids, and hydraulic fluids. High EPtype oils, for
sliding.
example, those oils meeting the requirements ofAPI GL-4 and
3.2 Definitions of Terms Specific to This Standard:
GL-5, generally exceed the capacity of the test rig and,
3.2.1 polishing—a mild form of abrasive wear resulting in
therefore, cannot be differentiated with this test method.
minor loss of material and typically characterized by a smooth
1.2 The values stated in SI units are to be regarded as the
finish and removal of all or part of the initial grinding marks.
standard. The values in parentheses are for information only.
1.3 This standard does not purport to address all of the
4. Summary of Test Method
safety concerns, if any, associated with its use. It is the
4.1 An FZG Gear Test Machine is operated at constant
responsibility of the user of this standard to establish appro-
speed (1450 rpm) for a fixed period (21700 revolutions—
priate safety and health practices and determine the applica-
approximately 15 min) at successively increasing loads until
bility of regulatory limitations prior to use. For specific safety
the failure criteria is reached; the initial oil temperature is 90°C
information, see Section 7, Section 8, 9.2, and 9.3.1.
beginning at load stage four (see Table 1). The test gears are
2. Referenced Documents examined initially and after the prescribed duration at each
load stage for cumulative damage (scuffing) to the gear tooth
2.1 ASTM Standards:
flanks.
D 235 Specification for Mineral Spirits (Petroleum Spirits)
(Hydrocarbon Dry Cleaning Solvent)
5. Significance and Use
G 40 Terminology Relating to Erosion and Wear
4 5.1 The transmission of power in many automotive and
2.2 DIN Standard:
industrial applications is accomplished through the use of
DIN 51 354 Teil 1: FZG Zahnrad Verspannungs Prüf
geared systems. At higher operating speeds it is well known
maschine—Allgemeine Arbeitsgrundlagen
that the lubricant/additive system can be a significant factor in
3. Terminology preventing scuffing (adhesive wear) damage to gears. This test
method is used to screen the scuffing load capacity of oils used
3.1 Definitions:
to lubricate spur and helical (parallel axis) gear units.
5.2 The test method is limited by the capabilities of the
This test method is under the jurisdiction of ASTM Committee D02 on
equipment (test rig and gears), and the performance observed
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
may not directly relate to scuffing performance observed with
D02.L0.11 on Tribological Properties of Industrial Fluid Lubricants.
Current edition approved Apr. 10, 1997. Published October 1997. Originally
spiral bevel on hypoid gearing. It is also limited to discrimi-
published as D 5182 – 91. Last previous edition D 5182 – 91.
nating between oils with mild EP additives or less. Lubricants
Annual Book of ASTM Standards, Vol 06.04.
3 containing higher levels of additives, that is, those meeting the
Annual Book of ASTM Standards, Vol 03.02.
requirements of API GL4 or GL5, generally exceed the
Available from Deutsches Institut für Normung e. V., Beuth Verlag GmbH
10772 Berlin, Federal Republic of Germany.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
e1
D 5182 – 97 (2002)
TABLE 1 Standard Load Stages for FZG Scuffing Test
Total
Torque Tooth Hertzian
Load Work Load Clutch
on Normal Contact
A
Stage Trans- Loaded with
Pinion Force Pressure
mitted
(N·m) (N) (N/mm ) (kW·h)
1 3.3 99 146 0.19 H1
2 13.7 407 295 0.97 H2
3 35.3 1044 474 2.96 H2+K
4 60.8 1799 621 6.43 H2+K+W1
5 94.1 2786 773 11.8 H2+K+W1+W2
6 135.5 4007 929 19.5 H2+.+W3
7 183.4 5435 1080 29.9 H2+.+W4
8 239.3 7080 1232 43.5 H2+.+W5
9 302.0 8949 1386 60.8 H2+.+W6
10 372.6 11029 1539 82.0 H2+.+W7
11 450.1 13342 1691 107.0 H2+.+W8
12 534.5 15826 1841 138.1 H2+.+W9
A
Where:
H1 = load lever H1 (light),
H2 = load lever H2 (heavy),
K = support rod for weights, and
A. Diagram of a Typical FZG Test Rig
W1 to W9 = weights for loading (supplied with test rig).
maximum load capacity of the test rig and, therefore, cannot be
distinguished for their scuffing capabilities by this test method.
6. Apparatus
6.1 FZG Gear Test Rig:
6.1.1 A more complete description of the test rig and
operating instructions may be found in the instruction manuals
availablefromthemanufacturers/suppliersidentifiedinA2.1.2.
6.1.2 The FZG gear test rig utilizes a recirculating power
loop principle, also known as a four-square configuration, to
provide a fixed torque (load) to a pair of precision test gears.A B. Schematic Section of an FZG Test Rig
schematic of the test rig is shown in Fig. 1a and Fig. 1b. The
FIG. 1 FZG Test Rig
drive gearbox and the test gearbox are connected through two
torsional shafts. Shaft 1 contains a load coupling used to apply
TABLE 2 Detail Data for the “A” Profile Gears
the torque through the use of known weights hung on the
Parameter Value Units
loading arm.
Center Distance 91.5 mm
6.1.3 The test gearbox contains heating and cooling ele-
Effective Tooth Width 20.0 mm
Pitch Circle Diameter:
ments to maintain and control the temperature of the oil. A
Pinion 73.2 mm
temperature sensor located in the side of the test gearbox is
Gear 109.8 mm
used to control the heating/cooling system as required by the
Tip Diameter:
Pinion 88.7 mm
test operating conditions.
Gear 112.5 mm
6.1.4 The test rig is driven by an electric motor capable of
Module 4.5 mm
delivering at least 5.5 kW (7.4 HP) at 1440 rpm.
Number of Teeth:
Pinion 16
6.2 Test Gears—The test gearset (pinion and gear) are
Gear 24
commonly referred to as type A profile and conform to the
Profile Modification
information supplied in Table 2. A schematic of the profile is Pinion/Gear 0.8635/−0.5103
Pressure Angle
shown in Fig. 2. Both sides of the test gear flanks can be used
Normal/Working 20/22.5 degrees
for testing purposes since only one side is loaded during the
Hardness
evaluation. It should be noted that these gears have been
Rockwell C 60 to 62
Surface Roughness
designedwithalargeprofilemodificationwhichincreasestheir
Ra 0.3 to 0.7 µm
sensitivity to adhesive wear modes of failure.
6.3 Timer Mechanism—A suitable timer or revolution
counter must be used to control the number of revolutions
7. Reagents and Materials
during each load stage of the test. The timer should be capable
of shutting down the test rig at the appropriate time. 7.1 Mineral Spirits (Stoddard Solvent).(Warning—
6.4 Hot Plate—A hot plate or suitable heating device is Combustible. Vapor harmful. Keep away from heat, sparks,
requiredtowarmthegearsto60to80°Cforassemblyontothe and open flame (see Annex A1.1). Type I conforming to the
shafts. requirements outlined in Specification D 235.)
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D 5182 – 97 (2002)
9.3.1 It has been found critical for correct results that the
test gears are properly aligned on their respective shafts.
(Warning—Misalignment can lead to erratic or lower fail
loads due to uneven distribution of the load on the tooth.)
9.4 Test Oil—Add 1.25 L of test oil to the test gearbox
(approximately to the centerline of the shafts).
9.5 Final Assembly—Secure the top of the test gear case in
place wit
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