ASTM G111-97(2013)
(Guide)Standard Guide for Corrosion Tests in High Temperature or High Pressure Environment, or Both
Standard Guide for Corrosion Tests in High Temperature or High Pressure Environment, or Both
SIGNIFICANCE AND USE
5.1 HP and HTHP corrosion tests are commonly used to evaluate the corrosion performance of metallic materials under conditions that attempt to simulate service conditions that involve HP or HTHP in combination with service environments. Examples of service environments where HP and HTHP corrosion tests have been utilized include chemical processing, petroleum production and refining, food processing, pressurized cooling water, electric power systems and aerospace propulsion.
5.2 For the applications of corrosion testing listed in 5.1, the service involves handling corrosive and potentially hazardous media under conditions of high pressure or high temperature, or both. The temperature and pressure usually enter directly into the severity of the corrosion process. Consequently, the laboratory evaluation of corrosion severity cannot be performed in conventional low pressure glassware without making potentially invalid assumptions as to the potential effects of high temperature and pressure on corrosion severity.
5.3 Therefore, there is a substantial need to provide standardized methods by which corrosion testing can be performed under HP and HTHP. In many cases, however, the standards used for exposure of specimens in conventional low pressure glassware experiments cannot be followed due to the limitations of access, volume and visibility arising from the construction of high pressure test cells. This guide refers to existing corrosion standards and practices as applicable and then goes further in areas where specific guidelines for performing HP and HTHP corrosion testing are needed.
SCOPE
1.1 This guide covers procedures, specimens, and equipment for conducting laboratory corrosion tests on metallic materials under conditions of high pressure (HP) or the combination of high temperature and high pressure (HTHP). See 3.2 for definitions of high pressure and temperature.
1.2 Tests conducted under HP or HTHP by their nature have special requirements. This guide establishes the basic considerations that are necessary when these conditions must be incorporated into laboratory corrosion tests.
1.3 The procedures and methods in this guide are applicable for conducting mass loss corrosion, localized corrosion, and electrochemical tests as well as for use in environmentally induced cracking tests that need to be conducted under HP or HTHP conditions.
1.4 The primary purpose for this guide is to promote consistency of corrosion test results. Furthermore, this guide will aid in the comparison of corrosion data between laboratories or testing organizations that utilize different equipment.
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
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 and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
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
Designation: G111 − 97 (Reapproved 2013)
Standard Guide for
Corrosion Tests in High Temperature or High Pressure
Environment, or Both
This standard is issued under the fixed designation G111; 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 G1 Practice for Preparing, Cleaning, and Evaluating Corro-
sion Test Specimens
1.1 This guide covers procedures, specimens, and equip-
G3 Practice for Conventions Applicable to Electrochemical
ment for conducting laboratory corrosion tests on metallic
Measurements in Corrosion Testing
materials under conditions of high pressure (HP) or the
G5 Reference Test Method for Making Potentiodynamic
combination of high temperature and high pressure (HTHP).
Anodic Polarization Measurements
See 3.2 for definitions of high pressure and temperature.
G15 Terminology Relating to Corrosion and Corrosion Test-
1.2 Tests conducted under HPor HTHPby their nature have
ing (Withdrawn 2010)
special requirements. This guide establishes the basic consid-
G30 Practice for Making and Using U-Bend Stress-
erations that are necessary when these conditions must be
Corrosion Test Specimens
incorporated into laboratory corrosion tests.
G31 Guide for Laboratory Immersion Corrosion Testing of
1.3 The procedures and methods in this guide are applicable
Metals
for conducting mass loss corrosion, localized corrosion, and
G34 Test Method for Exfoliation Corrosion Susceptibility in
electrochemical tests as well as for use in environmentally
2XXX and 7XXX Series Aluminum Alloys (EXCO Test)
induced cracking tests that need to be conducted under HP or
G38 Practice for Making and Using C-Ring Stress-
HTHP conditions.
Corrosion Test Specimens
1.4 The primary purpose for this guide is to promote G39 Practice for Preparation and Use of Bent-Beam Stress-
Corrosion Test Specimens
consistency of corrosion test results. Furthermore, this guide
will aid in the comparison of corrosion data between labora- G46 Guide for Examination and Evaluation of Pitting Cor-
tories or testing organizations that utilize different equipment. rosion
G49 Practice for Preparation and Use of Direct Tension
1.5 The values stated in SI units are to be regarded as
Stress-Corrosion Test Specimens
standard. The values given in parentheses are for information
G59 Test Method for Conducting Potentiodynamic Polariza-
only.
tion Resistance Measurements
1.6 This standard does not purport to address all of the
G78 Guide for Crevice Corrosion Testing of Iron-Base and
safety concerns, if any, associated with its use. It is the
Nickel-Base Stainless Alloys in Seawater and Other
responsibility of the user of this standard to establish appro-
Chloride-Containing Aqueous Environments
priate safety and health practices and determine the applica-
G106 Practice for Verification of Algorithm and Equipment
bility of regulatory limitations prior to use.
for Electrochemical Impedance Measurements
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
E8 Test Methods for Tension Testing of Metallic Materials 3.1 Definitions—ThedefinitionsoftermsgiveninTerminol-
ogy G15 shall be considered as applying to this guide.
3.2 Definitions of Terms Specific to This Standard:
This guide is under the jurisdiction ofASTM Committee G01 on Corrosion of
Metals and is the direct responsibility of Subcommittee G01.05 on Laboratory
3.2.1 high pressure—a pressure above ambient atmospheric
Corrosion Tests.
pressure that cannot be contained in normal laboratory glass-
CurrenteditionapprovedMay1,2013.PublishedJuly2013.Originallyapproved
ware. Typically, this is greater than 0.07 MPa (10 psig).
in 1992. Last previous edition approved in 2006 as G111–97 (2006). DOI:
10.1520/G0111-97R13.
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G111 − 97 (2013)
3.2.2 high temperature—temperatures above ambient labo- 6.2.1 The term effectively non-reactive shall mean that the
ratory temperature where sustained heating of the environment test cell shall be free of significant mass loss or localized
is required. corrosion, SCC or other embrittlement phenomena in the test
environment, not contaminate the test environment with cor-
4. Summary of Guide
rosion or other reaction products, and not consume or absorb
reactive chemical species from the test environment.
4.1 This guide describes the use of corrosion coupons,
stressed SCC specimens, and electrochemical electrodes in HP
6.3 The test cell shall have a seal mechanism that can
andHTHPenvironments.Italsoincludesguidelinesfortheuse
withstand both the pressures, temperatures, and corrosive
of high pressure test cells with these specimens to conduct
environment to be used in the test. Periodic hydrostatic testing
reproducible, accurate corrosion test data.
of the test cell is recommended to ensure pressure capabilities.
4.2 Typically, HP and HPHT tests involve exposure of test
6.4 The test cell shall be designed to have the necessary
specimens to a liquid (aqueous or non-aqueous), gaseous or
inlet and outlet ports to allow the test environment to be
multiphase environment, or both, in an appropriate test cell.
established in a controllable manner, monitored and sampled
Thetestcellmustbeabletoresistcorrosionandenvironmental
during the exposure period, released in a controlled manner at
cracking in the test environment while containing the
the completion of the test, and if over temperature or pressure
pressurized, heated environment. Furthermore, the test speci-
conditions may occur, adequate over pressure release and over
mens in the HPor HPHTtest, or both, can be exposed in either
temperature control equipment should be utilized.
stressed or unstressed condition in either the free corroding
6.5 In cases where external loading fixtures are used for
state or under electrochemical polarization.
stressing specimens in the HP and HTHP test environment,
specially designed feed-throughs shall be used which provide
5. Significance and Use
for a minimum of friction force.
5.1 HP and HTHP corrosion tests are commonly used to
6.6 Test cell feed-throughs required for external stressing
evaluate the corrosion performance of metallic materials under
may be designed to balance the internal pressure in the test
conditions that attempt to simulate service conditions that
vessel.
involve HP or HTHP in combination with service environ-
ments.ExamplesofserviceenvironmentswhereHPandHTHP 6.7 Any frictional or pressure forces (or thermal expansion)
corrosion tests have been utilized include chemical processing, acting on the specimen through the stressing fixtures must be
petroleum production and refining, food processing, pressur- taken into account when determining the actual load on the
ized cooling water, electric power systems and aerospace specimen.
propulsion.
6.8 Stressing and electrode feed-throughs shall be designed
5.2 Fortheapplicationsofcorrosiontestinglistedin5.1,the sothattheelectrodesorstressingrodsandspecimenscannotbe
service involves handling corrosive and potentially hazardous
ejected from the test cell under pressure. Furthermore, they
media under conditions of high pressure or high temperature, shall provide for electrical isolation of the specimen from the
or both. The temperature and pressure usually enter directly
test cell unless galvanic coupling is specifically desired.
into the severity of the corrosion process. Consequently, the
6.9 Gripping devices shall be designed such that they are in
laboratory evaluation of corrosion severity cannot be per-
compliance with Test Method E8 where application of load to
formedinconventionallowpressureglasswarewithoutmaking
the specimen is required.
potentially invalid assumptions as to the potential effects of
7. Reagents
high temperature and pressure on corrosion severity.
7.1 In corrosion testing, providing a reproducible chemical
5.3 Therefore, there is a substantial need to provide stan-
environment in which to expose the corrosion test specimens is
dardized methods by which corrosion testing can be performed
necessary.
under HP and HTHP. In many cases, however, the standards
used for exposure of specimens in conventional low pressure
7.2 Incaseswherethetestenvironmentisestablishedbythe
glassware experiments cannot be followed due to the limita-
mixing of chemicals in the laboratory, chemicals of reagent
tions of access, volume and visibility arising from the con-
grade purity with known contaminant levels are recommended.
struction of high pressure test cells. This guide refers to
Simulations of service environments can be formulated in
existing corrosion standards and practices as applicable and
which laboratory corrosion tests can be conducted.
then goes further in areas where specific guidelines for
7.3 In HP/HTHP corrosion testing, a common practice is to
performing HP and HTHP corrosion testing are needed.
conduct tests in environments that have been sampled and
retrieved from field or plant locations. In both cases described
6. Apparatus
in 7.2 and 7.3, detailed information as to the chemical
6.1 The test cell shall be constructed to applicable standards
composition of the environment should be obtained. Particular
and codes so that it will have an adequate pressure rating to
attention should be given to the levels of impurities and
safely handle the test pressure.
contaminants that may be in the environment. Furthermore,
6.2 The test cell shall be made of materials that are under some conditions, these environments may be prone to
corrosion resistant and effectively non-reactive with the test changes after sampling or during testing which can affect the
environment. corrosion test results.
G111 − 97 (2013)
7.4 In many cases, the test cells used to conduct HPtests are 8.3.4 In cases such as direct tension and fracture mechanics
limited in volume and may not be designed to accommodate tests,useofexternalloadingframesandfixturesinconjunction
replenishment of the environment. Therefore, monitoring the with HP and HTHP corrosion tests may be desirable. In these
chemical composition of the environment during the exposure cases, take both the frictional (sealing) forces and pressure
may be necessary to identify if depletion of reactive constitu- forces acting on the specimens into account when determining
ents or concentration of constituents has occurred. In some the effect of applied stress.
cases, replenishment or changing of the test environment may
8.4 Electrochemical Electrodes:
be necessary so that a valid corrosion test can be conducted.
8.4.1 Prepare electrodes for use in HP and HTHP corrosion
7.5 In all cases, it is recommended that the test environment
studies as described in Practice G3, Test Method G5, and
be fully documented with respect to its chemical composition.
Practices G59 and G106.
8.4.2 Cylindrical electrode specimens where only the lower
8. Test Specimens
portion of the electrode is exposed to the liquid phase of test
8.1 Preparation of Specimens:
environment and where the electrical connections are made
8.1.1 The primary objective is to prepare a reproducible
externally to the test cell are a convenient geometry. Care must
metallic surface with an absolute minimum of coldworking
be taken to electrically isolate the electrodes from the test cell.
followed by cleaning and degreasing.
Other electrode geometries and designs may be used that
8.1.2 Since test cells for HP and HTHP tests are usually of
facilitate feed-through and electrical isolation.
metallic construction, care must be taken to electrically isolate
8.4.3 A critical portion of the HP or HTHP electrochemical
the specimens from the test cell unless galvanic coupling is
system is the design and construction of the reference elec-
specifically desired in the test. In cases where the test cell is
trode. It is common to use external reference cells that use
used as a member of a galvanic couple, care must be taken to
stable reference systems such as Ag/AgCl or other stable
ensure that the galvanic action (anodic or cathodic) does not
electrochemical reference system that can be enclosed in a
degrade the integrity of the test cell.
separate pressure containing compartment. This cell is then
8.2 Corrosion Specimens:
connected to the test cell via a salt bridge and is pressure
8.2.1 Prepare specimens used in HP or HTHP corrosion
balanced with the test cell to minimize ingress of contaminants
testsinaccordancewithPracticesG1andG31.Commonly,test
into either the test cell or the reference electrode.Alternatively,
cells used for HP and HTHP exposure tests are restricted in
an inert or corroding metal electrode can be used as a
volume. The available volume in the test cell often decreases
pseudo-reference electrode in some cases. Examples of such
with increasing pressure rating. Therefore, it is frequently
pseudo-reference electrodes include platinum, graphite, or
necessary to restrict the size and surface area of corrosion
other metal with known stable corrosion potential. However,
coupons used in HP and HTHP corrosion tests.
one problem that can occur with this technique is a drift in
8.2.2 The ratio of solution volume-to-specimen surface area
reference potential with time. Care should be taken when
is important and a minimum ratio of 30 mL/cm should be
employing such methods. These pseudo-reference electrodes
maintained, where possible. If the ratio drops below this level,
can effectively give a measure of relative potential even if the
it should be shown that there will not be an unacceptably high
absolute potential is not known.
depletionrateofimportantenvironmentalconstituents,orthere
will not be an undesirable amount of metal ion impurities
9. Test Environment
added into the test environment during the period of exposure.
9.1 Choose the test environment to either simulate the most
In all cases, the solution volume-to-specimen surfaces area
accurate representation of the service environment possible
used in the test should be stated. If the test cell, specimen
under the constraints of the equipment available or provide for
holders or stressing fixtures can contribute to the conditions
a simple screening enviro
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