ASTM D6138-97
(Test Method)Standard Test Method for Determination of Corrosion-Preventive Properties of Lubricating Greases Under Dynamic Wet Conditions (Emcor Test)
Standard Test Method for Determination of Corrosion-Preventive Properties of Lubricating Greases Under Dynamic Wet Conditions (Emcor Test)
SCOPE
1.1 This test method covers the determination of corrosion-preventive properties of greases using greas-lubricated ball bearings under dynamic wet conditions.
1.2 The values stated in acceptable SI units are 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 health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: D 6138 – 97
Standard Test Method for
Determination of Corrosion -Preventive Properties of
Lubricating Greases Under Dynamic Wet Conditions (Emcor
Test)
This standard is issued under the fixed designation D 6138; 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 3. Terminology
1.1 This test method covers the determination of corrosion- 3.1 Definitions of Terms Specific to This Standard:
preventive properties of greases using grease- lubricated ball 3.1.1 corrosion, n—red rust or black spots on the race.
bearings under dynamic wet conditions. 3.1.1.1 Discussion—In this test method, any stain through
1.2 The values stated in acceptable SI units are standard. which the underlying metal surface is still visible shall be
1.3 This standard does not purport to address all of the ignored.
safety concerns, if any, associated with its use. It is the 3.2 Definitions:
responsibility of the user of this standard to establish appro- 3.2.1 lubricating grease, n—a semifluid to solid product of
priate safety and health practices and determine the applica- a thickener in a liquid lubricant.
bility of regulatory limitations prior to use. 3.2.1.1 Discussion—The dispersion of the thickener forms a
two-phase system and immobilizes the liquid lubricant by
2. Referenced Documents
surface tension and other physical forces. Other ingredients are
2.1 ASTM Standards: commonly included to impart special properties. D 217
D 217 Test Method for Cone Penetration of Lubricating
3.2.2 thickener, n— in lubricating grease, a substance
Grease composed of finely-divided particles dispersed in a liquid
D 235 Specification for Mineral Spirits (Petroleum Spirits)
lubricant to form the product’s structure.
(Hydrocarbon Dry Cleaning Solvent) 3.2.2.1 Discussion—The thickeners can be fibers (such as
D 665 Test Method for Rust-Preventing Characteristics of
various metallic soaps) or plates or spheres (such as certain
Inhibited Mineral Oil in the Presence of Water non-soap thickener), which are insoluble or, at most, only very
D 1193 Specification for Reagent Water
slightly soluble in the liquid lubricant. The general require-
2.2 ISO Standards: ments are that the solid particles be extremely small, uniformly
ISO 15 Rolling bearings - Radial bearings - Boundary
dispersed, and capable of forming a relatively stable, gel-like
dimensions - General plan structure with the liquid lubricant. D 217
ISO 3696 Water for analytical laboratory use - Specifica-
4. Summary of Test Method
tions and test methods
ISO 7120 Petroleum products and lubricants - Petroleum 4.1 New, cleaned, and lubricated bearings are tested par-
oils and other fluids - Determination of rust-preventing tially immersed in water (distilled, synthetic sea water or
characteristics in the presence of water sodium chloride solution) under no applied load at a speed of
83 6 5 rpm in a predetermined sequence of running and
stopping for a period of approximately one week. After
This test method is under the jurisdiction of ASTM Committee D02 on
cleaning, the bearing rings are examined and rated according to
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
the degree of corrosion.
D02.G on Lubricating Grease.
Current edition approved June 10, 1997. Published September 1997.
Annual Book of ASTM Standards, Vol 05.01.
Annual Book of ASTM Standards, Vol 11.01.
Available from American National Standards Institute, 11 W. 42nd St., 13th
floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D6138–97
5. Significance and Use 7.7.1 90 % Isopropyl alcohol.
7.7.2 9 % Distilled water.
5.1 This test method is used to assess the ability of grease to
7.7.3 1 % Ammonium hydroxide, 3.2-mol/L concentration.
prevent corrosion in rolling bearings operated in the presence
of distilled water, sodium chloride solution, or synthetic sea
NOTE 4—Warning: Flammable. Poison. Causes burns. Vapor ex-
water. It is used for development and specification purposes. tremely irritating. May be fatal if swallowed. Harmful if inhaled.
7.8 Mineral Spirits, conforming to Specification D 235.
6. Apparatus
NOTE 5—Warning: Combustible. Vapor Harmful.
6.1 Test Bearings— Use a double row self-aligning ball
bearing (30 by 72 by 19 mm), conforming to 1306 K of ISO 15,
8. Preparation of Bearings
with a steel cage. In cases of dispute, the SKF bearing
8.1 Examine the test bearings carefully and select only
specified in Footnote 5 shall be used as the referee bearing.
bearings that have outer rings and balls entirely free of
6.2 SKF TMG/Emcor Test Machine, see Annex A1. for
6 corrosion. During the bearing preparation, handle the bearings
description.
with tongs or protective gloves. Do not touch the bearings with
6.3 Dentist’s Mirror, non-magnifying.
bare fingers at any time. Use two new bearings for each grease
6.4 Graduated Pipette, capable of measuring 20 6 1mL
being tested.
water.
8.2 Number bearings on the outside diameter of the outer
6.5 Oven, capable of maintaining 90 6 2°C.
ring, but do not use chemical etching. One method to number
7. Reagents the bearings is with an electric pen, which should be grounded
on the outer ring surface being marked.
7.1 Purity of Reagents—Reagent grade chemicals shall be
8.3 Wash the selected bearings thoroughly in hot (50 to
used in all tests. Unless otherwise indicated, it is intended that
65°C) mineral spirits (Warning—see Note 5) to remove the
all reagents shall conform to the specifications of the Commit-
rust preventive. To ensure complete removal, subject the
tee on Analytical Reagents of the American Chemical Society,
7 bearing to a second wash in fresh hot mineral spirits.
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
NOTE 6—Warning: The washing temperatures specified are consider-
sufficiently high purity to permit its use without lessening the
ably above the flash point of the solvent. Accordingly, the washing
operation should be carried out in a well-ventilated hood where no ignition
accuracy of the determination.
source is present.
7.2 Purity of Water— Unless otherwise indicated, refer-
ences to water shall be understood to mean reagent water as
8.4 Transfer bearings to the solvent rinse solution (Warn-
defined by Grade 2 of ISO 3696.
ing–see Note 4) to remove any mineral spirits which may be
7.3 Synthetic Sea Water—If required, as specified in Speci-
present. Rinse each bearing and slowly rotate one ring relative
fication D 665, and ISO 7120.
to the other ring in fresh hot (65 65°C) solvent rinse solution.
7.4 Sodium Chloride Solution—a 0.5- mol/L solution of
Fresh rinse solution is used to avoid the selective evaporation
sodium chloride prepared using water conforming to Grade 2
of the components at the rinse temperature.
of ISO 3696, at a pH of 8.0 to 8.2 adjusted by titration with
NOTE 7—Care must be taken when handling bearings in the hot rinse
sodium hydroxide solution.
solution to avoid burns. Tongs and heat resistant gloves are recommended.
NOTE 1—Other water types, such as that specified in Specification
8.5 Remove each bearing from the solvent rinse solution
D 1193, Type III, can be used in this test method, although the precision
and place on filter paper to drain. After draining, dry the
when using other water types has not been determined. It is recommended
bearing in an oven at 90 6 2°C for 15 to 30 min.
that the pH of the other water types is determined before use.
8.6 Permit the bearing to cool to room temperature and
7.5 Isopropyl Alcohol:
reexamine the surfaces to ensure that corrosion-free bearings
have been selected. (Exercise care when handling the bearing
NOTE 2—Warning: Flammable. Poison. Causes burns. Vapor ex-
tremely irritating. May be fatal if swallowed. Harmful if inhaled. to avoid rotating one ring relative to the other ring after
cleaning and drying.)
7.6 Ammonium Hydroxide:
NOTE 3—Warning: Flammable. Poison. Causes burns. Vapor ex-
tremely irritating. May be fatal if swallowed. Harmful if inhaled.
7.7 Solvent Rinse Solution, of the following composition by
volume:
1306 K steel caged bearing manufactured by NTN and DKF may be used;
however, precision had only been evaluated using SKF 1306 K/236 725 bearings.
Available from Petrolab Corp., Latham, NY.
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the
...
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