ASTM D8485-23

Standard Test Method for Corrosion Test for Electric Vehicle Coolants in Glassware

SIGNIFICANCE AND USE
5.1 This test method provides a method to distinguish between coolants that are deleterious from the corrosion standpoint and those suitable for further evaluation.
FIG. 1 Metal Specimens and Equipment for the 336 h Corrosion Test
FIG. 2 Tall Form Beaker Specimens and Equipment for the 336 h Corrosion Test
SCOPE
1.1 This test method covers a simple beaker-type procedure for evaluating the effects of glycol-based electric vehicle coolants on metal specimens under controlled laboratory conditions.  
1.2 This test method evaluates the corrosion on test specimens of stainless steel and aluminum, with an option for a copper test specimen.  
1.3 This test method evaluates coolants without the addition of any corrosive elements.  
1.4 Additional types of metal test specimens may be evaluated.  
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 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.

General Information

• Status: Published
• Publication Date: 30-Jun-2023
• ICS: 71.100.45 - Refrigerants and antifreezes
• ICS: 77.060 - Corrosion of metals
• Technical Committee: D15 - Engine Coolants and Related Fluids
• Drafting Committee: D15.93 - Research and Long Range Planning

Relations

• Refers: ASTM D1384-24 - Standard Test Method for Corrosion Test for Engine Coolants in Glassware
• Effective Date: 01-Jan-2024
• Refers: ASTM D1384-05(2019) - Standard Test Method for Corrosion Test for Engine Coolants in Glassware
• Effective Date: 01-Oct-2019
• Refers: ASTM D6130-11(2018) - Standard Test Method for Determination of Silicon and Other Elements in Engine Coolant by Inductively Coupled Plasma-Atomic Emission Spectroscopy
• Effective Date: 01-Mar-2018
• Refers: ASTM E178-16 - Standard Practice for Dealing With Outlying Observations
• Effective Date: 01-Jun-2016
• Refers: ASTM D4725-13 - Standard Terminology for Engine Coolants and Related Fluids
• Effective Date: 01-Oct-2013
• Refers: ASTM D1384-05(2012) - Standard Test Method for Corrosion Test for Engine Coolants in Glassware
• Effective Date: 01-Apr-2012
• Refers: ASTM D6130-11 - Standard Test Method for Determination of Silicon and Other Elements in Engine Coolant by Inductively Coupled Plasma-Atomic Emission Spectroscopy
• Effective Date: 01-Nov-2011
• Refers: ASTM D4725-11 - Standard Terminology for Engine Coolants
• Effective Date: 01-Jun-2011
• Refers: ASTM D6130-97a(2009) - Standard Test Method for Determination of Silicon and Other Elements in Engine Coolant by Inductively Coupled Plasma-Atomic Emission Spectroscopy
• Effective Date: 01-Nov-2009
• Refers: ASTM E178-08 - Standard Practice for Dealing With Outlying Observations
• Effective Date: 01-Oct-2008
• Refers: ASTM D4725-08a - Standard Terminology for Engine Coolants
• Effective Date: 01-Jun-2008
• Refers: ASTM D4725-08 - Standard Terminology for Engine Coolants
• Effective Date: 15-May-2008
• Refers: ASTM D4725-06 - Standard Terminology for Engine Coolants
• Effective Date: 01-Jun-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1384-05e1 - Standard Test Method for Corrosion Test for Engine Coolants in Glassware
• Effective Date: 01-Jun-2005

Overview

ASTM D8485-23 is the Standard Test Method for Corrosion Test for Electric Vehicle Coolants in Glassware. Developed by ASTM, this international standard provides a laboratory procedure to evaluate the corrosive effects of glycol-based electric vehicle (EV) coolants on specific metals. The method helps distinguish between coolants that are potentially harmful due to corrosion and those suitable for further service evaluation. It is a crucial screening tool for manufacturers, researchers, and quality assurance professionals in the electric vehicle industry.

Key Topics

• Purpose and Scope

  • Evaluates the impact of glycol-based coolants on metals typically used in electric vehicle thermal management systems.
  • Focuses on corrosion effects on stainless steel and aluminum, with an optional assessment of copper. Other metals can also be tested.
  • Designed as a screening test for new, unused coolant formulations without added corrosive agents.

• Test Method Highlights

  • Laboratory procedure immerses metal specimens in coolant under controlled conditions.
  • Test duration is 336 hours (two weeks) at 88°C.
  • Corrosion is assessed by measuring changes in specimen weight before and after testing.
  • Tests are performed in triplicate to account for variability and ensure reliable results.

• Test Specimens and Equipment

  • Stainless steel and aluminum are primary test specimens, with copper as an optional addition.
  • Utilizes glassware such as beakers or flasks, aerator tubes, thermometers, and condensers.
  • Equipment is assembled to maintain precise temperature, aeration rate, and cleanliness.

• Interpretation and Limitations

  • The method provides a comparative evaluation of corrosion inhibition only under controlled laboratory settings.
  • It does not assess inhibitor life, other coolant properties, or service simulative conditions.
  • The test is not a substitute for more comprehensive performance testing.

Applications

• Coolant Development and Screening

  • Early-stage screening of new EV coolant formulations for corrosion inhibition.
  • Research and development teams can quickly identify coolants that are unfit for further evaluation due to excessive corrosion potential.

• Quality Assurance in Manufacturing

  • Verification of coolant batches before approval and release to market.
  • Assurance that coolants meet baseline corrosion protection requirements for electric vehicle systems.

• Consumer and Qualification Testing

  • Third-party laboratories or qualification agencies can use the method to screen commercial coolant products.
  • Useful reference for regulatory compliance and technical specification checks in automotive supply chains.

• Industry Research

  • Investigation of the effects of various coolant compositions on popular automotive alloys.
  • Supports industry-wide efforts to standardize corrosion protection in the rapidly growing e-mobility sector.

Related Standards

• ASTM D1384 - Standard Test Method for Corrosion Test for Engine Coolants in Glassware
• ASTM D1125 - Test Methods for Electrical Conductivity and Resistivity of Water
• ASTM D1193 - Specification for Reagent Water
• ASTM D6130 - Determination of Silicon and Other Elements in Engine Coolant by ICP-Atomic Emission Spectroscopy
• ASTM E178 - Practice for Dealing With Outlying Observations
• ASTM E2470 - Specification for Polyester Grade Ethylene Glycol

These related standards provide additional guidance for evaluating coolant composition, quality, and performance in both electric and conventional vehicle applications.

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Keywords: electric vehicle coolant corrosion, ASTM D8485-23, glassware corrosion test, glycol-based coolant test, EV coolant standard, corrosion inhibition, battery electric vehicle, automotive coolant testing, laboratory test method for EV coolants, ASTM coolant standards

Standards Content (Sample)

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.
Designation: D8485 − 23
Standard Test Method for
Corrosion Test for Electric Vehicle Coolants in Glassware
This standard is issued under the fixed designation D8485; 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 Elements in Engine Coolant by Inductively Coupled
Plasma-Atomic Emission Spectroscopy
1.1 This test method covers a simple beaker-type procedure
E178 Practice for Dealing With Outlying Observations
for evaluating the effects of glycol-based electric vehicle
E2470 Specification for Polyester Grade Ethylene Glycol
coolants on metal specimens under controlled laboratory con-
ditions.
3. Terminology
1.2 This test method evaluates the corrosion on test speci-
3.1 Definitions: For definitions of general terms used in D15
mens of stainless steel and aluminum, with an option for a
standards, refer to Terminology D4725.
copper test specimen.
3.2 Definitions of Terms Specific to This Standard:
1.3 This test method evaluates coolants without the addition
3.2.1 electric vehicle, n—a motor vehicle that uses an
of any corrosive elements.
electric motor as a means of propulsion.
1.4 Additional types of metal test specimens may be evalu-
3.2.1.1 Discussion—An electric vehicle may be either a fuel
ated.
cell vehicle, battery electric vehicle or a plug-in hybrid electric
vehicle.
1.5 The values stated in SI units are to be regarded as
standard. The values given in parentheses after SI units are
4. Summary of Test Method
provided for information only and are not considered standard.
1.6 This standard does not purport to address all of the
4.1 In this test method, specimens of metals typical of those
safety concerns, if any, associated with its use. It is the present in electric vehicle cooling systems are totally immersed
responsibility of the user of this standard to establish appro-
in aerated coolant solutions for 336 h at 88 °C. The corrosion-
priate safety, health, and environmental practices and deter- inhibitive properties of the test solution are evaluated on the
mine the applicability of regulatory limitations prior to use. change in weight incurred by the specimens. Each test is run in
1.7 This international standard was developed in accor-
triplicate, and the average weight change is determined for
dance with internationally recognized principles on standard- each metal.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
5. Significance and Use
mendations issued by the World Trade Organization Technical
5.1 This test method provides a method to distinguish
Barriers to Trade (TBT) Committee.
between coolants that are deleterious from the corrosion
standpoint and those suitable for further evaluation.
2. Referenced Documents
2.1 ASTM Standards:
6. Apparatus
D1125 Test Methods for Electrical Conductivity and Resis-
6.1 Container—1000 mL 3-Neck Glass Cylinder Reactor,
tivity of Water
Flat Bottom Reaction Flask with a PTFE O-Ring and clamp.
D1193 Specification for Reagent Water
See Fig. 1.
D1384 Test Method for Corrosion Test for Engine Coolants
in Glassware
6.2 Water Condenser, joint size to match middle neck of
D4725 Terminology for Engine Coolants and Related Fluids
container in 6.1.
D6130 Test Method for Determination of Silicon and Other
6.3 Two inlet adapters to accommodate an aerator tube and
temperature probe. Joint size to match side necks of container
in 6.1.
This test method is under the jurisdiction of ASTM Committee D15 on Engine
Coolants and Related Fluids and is the direct responsibility of Subcommittee
6.4 Optionally a 1000 mL, tall-form, spoutless beaker, made
D15.93 on Research and Long Range Planning.
of heat-resistant glass, for containing the engine coolant
Current edition approved July 1, 2023. Published August 2023. DOI: 10.1520/
D8485-23 solution and test specimens. The beaker shall be tightly closed
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D8485 − 23
FIG. 1 Metal Specimens and Equipment for the 336 h Corrosion
Test
with a No. 15 rubber stopper, having drill holes to accommo- 6.7 Temperature Measuring Instrument—An electronic tem-
date a water condenser, an aerator tube, and a thermometer as perature measuring and recording device with a minimum
shown in Fig. 2.
accuracy of 62 °C within the specified test temperature range.
6.5 Temperature Measuring Device.
6.8 Heater—An electric hot plate or a constant-temperature
6.6 Aerator Tube—A gas dispersion tube with a 12 mm- bath containing a high boiling liquid that is capable of
diameter fritted cylinder with a coarse porosity (40 μm to maintaining the specified temperature. The size of the bath will
60 μm) to ensure continuous aeration without plugging.
be determined by the number of corrosion tests that are to be
Optionally, a capillary tip bleed tube with 7 mm bore and
run concurrently.
280 mm length may be used.
D8485 − 23
FIG. 2 Tall Form Beaker Specimens and Equipment for the 336 h
Corrosion Test
2,3
6.9 Metal Test Specimens: specimens separated by insulating spacers made from tetrafluo-
6.9.1 Stainless Steel S30400, cut from 1.59 mm ( ⁄16 in.) roethylene polymer and shall be used between the legs and the
sheet stock to size 51 mm by 25 mm (2 in. by 1 in.). specimens. The nut shall be tightened firmly to ensure test
6.9.2 Aluminum A93003, cut from 1.59 mm ( ⁄16 in.) sheet specimens do not come loose in bundle. (See Fig. 2 or Fig. 3).
stock to size 51 mm by 25 mm (2 in. by 1 in.).
NOTE 1—None of the hardware used in metal specimen arrangement
6.9.3 Copper C11000, cut from 1.59 mm ( ⁄16 in.) sheet
(metal specimen, screws, washers, spacers, insulating sleeves, insulating
stock to size 51 mm by 25 mm (2 in. by 1 in.).
spacers, and nuts) can be reused for a test.
6.10 Metal Specimen Assembly—The metal test specimens
7. Preparation of Test Specimens
shall be drilled through the center with a 6.75 mm drill to
accommodate a 51 mm 10–24 Tetrafluoroethylene polymer 7.1 Remove any burrs from coupon edges and hole. Scrub
all specimens vigorously, using a moistened bristle brush and
screw covered with a thin-walled insulating sleeve. Tetrafluo-
roethylene polymer tubing with a 6.35 mm outside diameter ground pumice powder or fine silicon carbide grit until the
entire metal area is bright, shiny, and free from any visible
1.59 mm wide and a wall thickness of 0.4 mm is satisfactory.
The legs shall be Tetrafluoroethylene polymer. A 6.35 mm oxide film or tarnish.
diameter hole shall be drilled in each leg with the center
7.2 Rinse the specimens thoroughly with tap water; then
6.35 mm from the top and 12.7 mm from each side. The test
rinse with acetone, dry, and weigh to the nearest 1 mg.
“bundle” shall be made up on the insulated screw with the
NOTE 2—If the test specimens are not to be used immediately, keep
them in a desiccator until required.
When assembling the test bundle, sizes are stated in SI units, adjustment to
these unit may be made to accommodate US customary units, for example, 51 mm 8. Test Solutions
or 2 in.
8.1 Prediluted coolant shall be tested as supplied. Concen-
Test specimens are available from suppliers of test specimens for Test Method
D1384. trated coolant shall be diluted as to a volume fraction of 50 %
D8485 − 23
FIG. 3 Stainless Steel SUS304 and Aluminum 3003 Tetrafluroethylene Polymer Spacers
FIG. 4 Stainless Steel SUS304, Aluminum 3003 and Copper Test Specimens
with Specification D1193 Type II or better water (<1 μS ⁄cm). 9.3 Aeration Rate—The aeration rate shall be 100 mL ⁄min
An aliquot of test solution shall be collected for conductivity 6 10 mL/min. The aerator tube should be located at least
and metals testing as described in 10.8.1. 13 mm away from the test “bundle” to avoid direct contact
with the metal specimens.
9. Test Conditions
9.4 Test Duration—The test shall be run continuously for
9.1 Test Container Assembly—The arrangement of the as- 336 h (2 weeks).
sembled metal specimens with relation to the aerator tube and
other components is shown in Fig. 1 or Fig. 2. 10. Procedure
9.2 Test Temperature—The test solution shall be maintained 10.1 Make triplicate tests concurrently on each coolant
at a temperature of 88 °C 6 2 °C. solution in accordance with the following procedure:
D8485 − 23
10.2 Carefully clean all components of reactor flask, hood.) The acid dip times given for the cleaning of Aluminum
condenser, and aerator tube, and thoroughly rinse with water. specimens are average values found to be adequate in most
cases. Other times, suggested by experience, may be used, if
10.3 Bolt the test specimens together and place the “bundle”
necessary, if
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