1、Designation: G111 97 (Reapproved 2013)Standard Guide forCorrosion Tests in High Temperature or High PressureEnvironment, or Both1This standard is issued under the fixed designation G111; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers procedures, specimens, and equip-ment for conducting laboratory corrosion tests on m
3、etallicmaterials under conditions of high pressure (HP) or thecombination 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 havespecial requirements. This guide establishes the basic consid-erati
4、ons that are necessary when these conditions must beincorporated into laboratory corrosion tests.1.3 The procedures and methods in this guide are applicablefor conducting mass loss corrosion, localized corrosion, andelectrochemical tests as well as for use in environmentallyinduced cracking tests th
5、at need to be conducted under HP orHTHP conditions.1.4 The primary purpose for this guide is to promoteconsistency of corrosion test results. Furthermore, this guidewill aid in the comparison of corrosion data between labora-tories or testing organizations that utilize different equipment.1.5 The va
6、lues stated in SI units are to be regarded asstandard. The values given in parentheses are for informationonly.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safe
7、ty and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E8 Test Methods for Tension Testing of Metallic MaterialsG1 Practice for Preparing, Cleaning, and Evaluating Corro-sion Test SpecimensG3 Practice for Conventions
8、 Applicable to ElectrochemicalMeasurements in Corrosion TestingG5 Reference Test Method for Making PotentiodynamicAnodic Polarization MeasurementsG15 Terminology Relating to Corrosion and Corrosion Test-ing (Withdrawn 2010)3G30 Practice for Making and Using U-Bend Stress-Corrosion Test SpecimensG31
9、Guide for Laboratory Immersion Corrosion Testing ofMetalsG34 Test Method for Exfoliation Corrosion Susceptibility in2XXX and 7XXX Series Aluminum Alloys (EXCO Test)G38 Practice for Making and Using C-Ring Stress-Corrosion Test SpecimensG39 Practice for Preparation and Use of Bent-Beam Stress-Corrosi
10、on Test SpecimensG46 Guide for Examination and Evaluation of Pitting Cor-rosionG49 Practice for Preparation and Use of Direct TensionStress-Corrosion Test SpecimensG59 Test Method for Conducting Potentiodynamic Polariza-tion Resistance MeasurementsG78 Guide for Crevice Corrosion Testing of Iron-Base
11、 andNickel-Base Stainless Alloys in Seawater and OtherChloride-Containing Aqueous EnvironmentsG106 Practice for Verification of Algorithm and Equipmentfor Electrochemical Impedance Measurements3. Terminology3.1 DefinitionsThe definitions of terms given in Terminol-ogy G15 shall be considered as appl
12、ying to this guide.3.2 Definitions of Terms Specific to This Standard:3.2.1 high pressurea pressure above ambient atmosphericpressure that cannot be contained in normal laboratory glass-ware. Typically, this is greater than 0.07 MPa (10 psig).1This guide is under the jurisdiction of ASTM Committee G
13、01 on Corrosion ofMetals and is the direct responsibility of Subcommittee G01.05 on LaboratoryCorrosion Tests.Current edition approved May 1, 2013. Published July 2013. Originally approvedin 1992. Last previous edition approved in 2006 as G11197 (2006). DOI:10.1520/G0111-97R13.2For referenced ASTM s
14、tandards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org
15、.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 high temperaturetemperatures above ambient labo-ratory temperature where sustained heating of the environmentis required.4. Summary of Guide4.1 This guide describes the use of cor
16、rosion coupons,stressed SCC specimens, and electrochemical electrodes in HPand HTHP environments. It also includes guidelines for the useof high pressure test cells with these specimens to conductreproducible, accurate corrosion test data.4.2 Typically, HP and HPHT tests involve exposure of testspec
17、imens to a liquid (aqueous or non-aqueous), gaseous ormultiphase environment, or both, in an appropriate test cell.The test cell must be able to resist corrosion and environmentalcracking in the test environment while containing thepressurized, heated environment. Furthermore, the test speci-mens in
18、 the HP or HPHT test, or both, can be exposed in eitherstressed or unstressed condition in either the free corrodingstate or under electrochemical polarization.5. Significance and Use5.1 HP and HTHP corrosion tests are commonly used toevaluate the corrosion performance of metallic materials undercon
19、ditions that attempt to simulate service conditions thatinvolve HP or HTHP in combination with service environ-ments. Examples of service environments where HPand HTHPcorrosion tests have been utilized include chemical processing,petroleum production and refining, food processing, pressur-ized cooli
20、ng water, electric power systems and aerospacepropulsion.5.2 For the applications of corrosion testing listed in 5.1, theservice involves handling corrosive and potentially hazardousmedia under conditions of high pressure or high temperature,or both. The temperature and pressure usually enter direct
21、lyinto the severity of the corrosion process. Consequently, thelaboratory evaluation of corrosion severity cannot be per-formed in conventional low pressure glassware without makingpotentially invalid assumptions as to the potential effects ofhigh temperature and pressure on corrosion severity.5.3 T
22、herefore, there is a substantial need to provide stan-dardized methods by which corrosion testing can be performedunder HP and HTHP. In many cases, however, the standardsused for exposure of specimens in conventional low pressureglassware experiments cannot be followed due to the limita-tions of acc
23、ess, volume and visibility arising from the con-struction of high pressure test cells. This guide refers toexisting corrosion standards and practices as applicable andthen goes further in areas where specific guidelines forperforming HP and HTHP corrosion testing are needed.6. Apparatus6.1 The test
24、cell shall be constructed to applicable standardsand codes so that it will have an adequate pressure rating tosafely handle the test pressure.6.2 The test cell shall be made of materials that arecorrosion resistant and effectively non-reactive with the testenvironment.6.2.1 The term effectively non-
25、reactive shall mean that thetest cell shall be free of significant mass loss or localizedcorrosion, SCC or other embrittlement phenomena in the testenvironment, not contaminate the test environment with cor-rosion or other reaction products, and not consume or absorbreactive chemical species from th
26、e test environment.6.3 The test cell shall have a seal mechanism that canwithstand both the pressures, temperatures, and corrosiveenvironment to be used in the test. Periodic hydrostatic testingof the test cell is recommended to ensure pressure capabilities.6.4 The test cell shall be designed to hav
27、e the necessaryinlet and outlet ports to allow the test environment to beestablished in a controllable manner, monitored and sampledduring the exposure period, released in a controlled manner atthe completion of the test, and if over temperature or pressureconditions may occur, adequate over pressur
28、e release and overtemperature control equipment should be utilized.6.5 In cases where external loading fixtures are used forstressing specimens in the HP and HTHP test environment,specially designed feed-throughs shall be used which providefor a minimum of friction force.6.6 Test cell feed-throughs
29、required for external stressingmay be designed to balance the internal pressure in the testvessel.6.7 Any frictional or pressure forces (or thermal expansion)acting on the specimen through the stressing fixtures must betaken into account when determining the actual load on thespecimen.6.8 Stressing
30、and electrode feed-throughs shall be designedso that the electrodes or stressing rods and specimens cannot beejected from the test cell under pressure. Furthermore, theyshall provide for electrical isolation of the specimen from thetest cell unless galvanic coupling is specifically desired.6.9 Gripp
31、ing devices shall be designed such that they are incompliance with Test Method E8 where application of load tothe specimen is required.7. Reagents7.1 In corrosion testing, providing a reproducible chemicalenvironment in which to expose the corrosion test specimens isnecessary.7.2 In cases where the
32、test environment is established by themixing of chemicals in the laboratory, chemicals of reagentgrade purity with known contaminant levels are recommended.Simulations of service environments can be formulated inwhich laboratory corrosion tests can be conducted.7.3 In HP/HTHP corrosion testing, a co
33、mmon practice is toconduct tests in environments that have been sampled andretrieved from field or plant locations. In both cases describedin 7.2 and 7.3, detailed information as to the chemicalcomposition of the environment should be obtained. Particularattention should be given to the levels of im
34、purities andcontaminants that may be in the environment. Furthermore,under some conditions, these environments may be prone tochanges after sampling or during testing which can affect thecorrosion test results.G111 97 (2013)27.4 In many cases, the test cells used to conduct HP tests arelimited in vo
35、lume and may not be designed to accommodatereplenishment of the environment. Therefore, monitoring thechemical composition of the environment during the exposuremay be necessary to identify if depletion of reactive constitu-ents or concentration of constituents has occurred. In somecases, replenishm
36、ent or changing of the test environment maybe necessary so that a valid corrosion test can be conducted.7.5 In all cases, it is recommended that the test environmentbe fully documented with respect to its chemical composition.8. Test Specimens8.1 Preparation of Specimens:8.1.1 The primary objective
37、is to prepare a reproduciblemetallic surface with an absolute minimum of coldworkingfollowed by cleaning and degreasing.8.1.2 Since test cells for HP and HTHP tests are usually ofmetallic construction, care must be taken to electrically isolatethe specimens from the test cell unless galvanic couplin
38、g isspecifically desired in the test. In cases where the test cell isused as a member of a galvanic couple, care must be taken toensure that the galvanic action (anodic or cathodic) does notdegrade the integrity of the test cell.8.2 Corrosion Specimens:8.2.1 Prepare specimens used in HP or HTHP corr
39、osiontests in accordance with Practices G1 and G31. Commonly, testcells used for HP and HTHP exposure tests are restricted involume. The available volume in the test cell often decreaseswith increasing pressure rating. Therefore, it is frequentlynecessary to restrict the size and surface area of cor
40、rosioncoupons used in HP and HTHP corrosion tests.8.2.2 The ratio of solution volume-to-specimen surface areais important and a minimum ratio of 30 mL/cm2should bemaintained, where possible. If the ratio drops below this level,it should be shown that there will not be an unacceptably highdepletion r
41、ate of important environmental constituents, or therewill not be an undesirable amount of metal ion impuritiesadded into the test environment during the period of exposure.In all cases, the solution volume-to-specimen surfaces areaused in the test should be stated. If the test cell, specimenholders
42、or stressing fixtures can contribute to the conditionsstated above then they should be included in the calculation ofspecimen surface area.8.3 Stressed Corrosion Specimens:8.3.1 Both self stressed and externally stressed specimensare acceptable for testing at HP and HTHP. Methods for thefabrication
43、and use of appropriate stressed specimens are givenin the referenced documents. These include tension, bent beam,C-ring, and U-bend specimens in accordance with PracticesG49, G39, G38, and G30, respectively. Fracture mechanicsspecimens can also be accommodated.8.3.2 For similar reasons given in 8.2,
44、 when testing multiplespecimens, it is recommended that the size of the specimens berestricted to the smallest applicable specimen provided forunder the appropriate standards.8.3.3 Due to the limited access of the specimens in HP andHTHP tests, self stressed specimens are usually more conve-nient th
45、an specimens that require external stressing fixtures.8.3.4 In cases such as direct tension and fracture mechanicstests, use of external loading frames and fixtures in conjunctionwith HP and HTHP corrosion tests may be desirable. In thesecases, take both the frictional (sealing) forces and pressuref
46、orces acting on the specimens into account when determiningthe effect of applied stress.8.4 Electrochemical Electrodes:8.4.1 Prepare electrodes for use in HP and HTHP corrosionstudies as described in Practice G3, Test Method G5, andPractices G59 and G106.8.4.2 Cylindrical electrode specimens where o
47、nly the lowerportion of the electrode is exposed to the liquid phase of testenvironment and where the electrical connections are madeexternally to the test cell are a convenient geometry. Care mustbe taken to electrically isolate the electrodes from the test cell.Other electrode geometries and desig
48、ns may be used thatfacilitate feed-through and electrical isolation.8.4.3 A critical portion of the HP or HTHP electrochemicalsystem is the design and construction of the reference elec-trode. It is common to use external reference cells that usestable reference systems such as Ag/AgCl or other stab
49、leelectrochemical reference system that can be enclosed in aseparate pressure containing compartment. This cell is thenconnected to the test cell via a salt bridge and is pressurebalanced with the test cell to minimize ingress of contaminantsinto either the test cell or the reference electrode. Alternatively,an inert or corroding metal electrode can be used as apseudo-reference electrode in some cases. Examples of suchpseudo-reference electrodes include platinum, graphite, orother metal with known stable corrosion potential. However,one problem that can occur with this technique i
