ASTM G162-2018 Standard Practice for Conducting and Evaluating Laboratory Corrosion Tests in Soils.pdf

1、Designation: G162 99 (Reapproved 2010)G162 18Standard Practice forConducting and Evaluating Laboratory Corrosion Tests inSoils1This standard is issued under the fixed designation G162; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision

2、, 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 practice covers procedures for conducting laboratory corrosion tests in soils to evaluate the corro

3、sive attack onengineering materials. The test is conducted under laboratory ambient temperature unless the effect of temperature is beingevaluated. This practice does not include provisions for microbiological influenced corrosion (MIC) testing, nor its influence onresults.1.2 This practice covers s

4、pecimen selection and preparation, test environments, evaluation, and evaluationreporting of testresults.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety conce

5、rns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of regulatory limitations prior to use.1.5 This international standard was developed in accordan

6、ce with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Stand

7、ards:2D698 Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3)D1193 Specification for Reagent WaterD1654 Test Method for Evaluation of Painted or Coated Specimens Subjected to Corrosive EnvironmentsD2570 Test Method for Simulated Serv

8、ice Corrosion Testing of Engine CoolantsG1 Practice for Preparing, Cleaning, and Evaluating Corrosion Test SpecimensG3 Practice for Conventions Applicable to Electrochemical Measurements in Corrosion TestingG4 Guide for Conducting Corrosion Tests in Field ApplicationsG16 Guide for Applying Statistic

9、s to Analysis of Corrosion DataG31 Guide for Laboratory Immersion Corrosion Testing of MetalsG46 Guide for Examination and Evaluation of Pitting CorrosionG51 Test Method for Measuring pH of Soil for Use in Corrosion TestingG57 Test Method for Field Measurement of Soil Resistivity Using the Wenner Fo

10、ur-Electrode MethodG71 Guide for Conducting and Evaluating Galvanic Corrosion Tests in ElectrolytesG102 Practice for Calculation of Corrosion Rates and Related Information from Electrochemical MeasurementsG187 Test Method for Measurement of Soil Resistivity Using the Two-Electrode Soil Box MethodG19

11、3 Terminology and Acronyms Relating to CorrosionG200 Test Method for Measurement of Oxidation-Reduction Potential (ORP) of SoilG215 Guide for Electrode Potential Measurement1 This practice is under the jurisdiction of ASTM Committee G01 on Corrosion of Metals and is the direct responsibility of Subc

12、ommittee G01.10 on Corrosion in Soils.Current edition approved Feb. 1, 2010Oct. 1, 2018. Published March 2010November 2018. Originally approved in 1999. Last previous edition approved in 20042010 asG162-99(2004).G162 99 (2010). DOI: 10.1520/G0162-99R10.10.1520/G0162-18.2 For referencedASTM standards

13、, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM s

14、tandard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by

15、ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13. Terminology3.1 Definitions:3.1.1 purified water, nwater that meets Specification D1193 Type IV requirements.3.2 For other definitions of

16、 terms used in this guide, refer to NACE/ASTM G193 (Standard Terminology and AcronymsRelating to Corrosion).4. Significance and Use4.1 This practice provides a controlled corrosive environment that has been utilized to produce relative corrosion information.4.2 The primary application of the data fr

17、om this practice is to evaluate metallic materials for use in soil environments.4.3 This practice may not duplicate all field conditions and variables such as stray currents, microbiologically influencedcorrosion, non-homogeneous conditions, and long cell corrosion. The reproducibility of results in

18、 the practice is highly dependenton the type of specimen tested and the evaluation criteria selected as well as the control of the operating variables. In any testingprogram, sufficient replicates should be included to establish the variability of the results.4.4 Structures and components may be mad

19、e of several different metals; therefore, the practice may be used to evaluate galvaniccorrosion effects in soils (see Guide G71).4.5 Structures and components may be coated with sacrificial or noble metal coatings, which may be scratched or otherwiserendered discontinuous (for example, no coating o

20、n the edges of metal strips cut from a wide sheet). This test is useful to evaluatethe effect of defective metallic coatings.4.6 Structures and components may be coated or jacketed with organic materials (for example, paints and plastics), and thesecoatings and jackets may be rendered discontinuous.

21、 The test is useful to evaluate the effect of defective or incompletely coveringcoatings and jackets.4.7 The corrosivity of soils strongly depends on soluble salt content (related parameters are chemistry and soil resistivity, seeTest MethodMethods G57, and G187chemistry),), acidity or alkalinity (m

22、easured by soil pH, see Test Method G51), and oxygencontent (loose, for example, sand, or compact, for example, clay, soils are extreme examples). examples, see Test MethodG200 oxidation-reduction potential). The manufacturer, supplier, or user, or combination thereof, should establish the nature of

23、the expected soil environment(s) and select the test environment(s) accordingly. Multiple types of soil can be used to determinethe effect of this variable.5. Test Apparatus and Conditions5.1 ContainerThe container for the soil shall be made from a material that is not affected by the soil environme

24、nt and thatdoes not affect the soil. Container materials, such as glass, plastic, or corrosion-resistant metal or alloy, can be used; however,electrically conductive containers must be electrochemically isolated from the specimens. The size of the container is determinedby the volume of soil require

25、d for the test. A minimum of 40 cm3 should be used for each 1 cm2 of exposed metal surface area(see Fig. 1).5.2 Soil EnvironmentThe container is filled with a soil sample of choice. A soil sample from a specific outdoor location maybe retrieved for the test, or a soil sample may be prepared with a s

26、pecific property and chemistry. If necessary, physical andchemical characteristics of the soil may be determined.5.2.1 A field soil sample may be utilized for purposes of conducting a soil corrosion test in a specific environment.5.2.2 Laboratory soil samples may be prepared by using washed sand, (t

27、hat is, No. 2 silica sand) clean clay (that is, bentonite)or other uniform known media.5.2.3 Soil ChemistryThe field soil sample and the laboratory soil sample are saturated with a known electrolyte chosen forthe test. Typically, the electrolyte is added to the soil of choice in the container. A typ

28、ical electrolyte for use with washed sand isASTM corrosive water (see Test Method D2570). With field soil samples, deionized or distilled water (see Test Method purifiedFIG. 1 Apparatus for Conducting Laboratory Corrosion Tests in SoilsG162 182water D2570) is commonly used. Periodically, deionized o

29、r distilled water (see Specification is commonly used to saturate the soiland D1193) is added periodically to maintain the soil in a saturated condition. A non-saturated condition can be maintained ifdesired.5.2.4 TemperatureThe test is conducted under laboratory ambient temperature unless the effec

30、t of temperature is beingevaluated.5.2.5 Test SpecimenThe test specimen is buried in the soil within the container and is prepared as discussed in Section 56.5.2.6 ScalesScales or balances are needed to determine mass loss of exposed samples. The capacity and accuracy of the scaleswill be determined

31、 by the configuration, size, and weight of the test specimen, and by the amount of mass loss needing to bemeasured based on the exposure period. In general, the more accurate the scale or balance, the lower the total capacity of thedevice.5.2.7 High Impedance Voltmeter (Guide G215)In general, device

32、s with input impedances greater than 107 ohms have beenfound to be acceptable in most corrosion related measurements.5.2.8 Current Measuring DeviceCapability and accuracy of the device needed will vary depending on the amount of currentgenerated by the specific type of galvanic couple being evaluate

33、d.5.2.9 CameraFor photographically documenting the test specimen before and after exposure, prior to cleaning, type andextent of corrosion, etc.6. Test Specimen6.1 MaterialPrepare the test specimens from the same material as that used in the structures or components being studied.Alternatively, use

34、test specimens from the actual products.6.2 Size and Shape:6.2.1 The size and shape of test specimens are dependent on several factors and cannot be rigidly defined. When determiningcorrosion behavior of metals in the laboratory, it is advisable to use the largest specimens permissible within the co

35、nstraints of thetest equipment. In general, the ratio of surface area to metal volume should be large in order to obtain maximum corrosion lossper specimen weight. However, sufficient thickness should be employed to minimize the possibility of perforation of the specimenduring the test exposure unle

36、ss an evaluation of perforation susceptibility is of interest. When modeling large structures orcomponents, the size of the specimens should be as large as practical. When modeling small components, the specimen size shouldbe as close as possible to that of the component modeled. When the structure

37、or component is made of two or more metals, thesurface area ratio of the test specimen should be similar to the structure or component being modeled.6.2.2 When modeling service applications, the shapes of the specimens should approximate the shapes in the application.Complex shapes are frequently si

38、mplified for testing purposes. For some tests, the specimen may be taken from the manufacturingline or cut from manufactured pieces (for example, short sections of pipes, wires, cables).6.2.3 When designing the test specimen, the weight of the specimen versus the expected weight loss should be consi

39、dered toobtain meaningful mass loss information based on scale capacity and accuracy. See 5.2.6.6.3 Specimen Preparation:6.3.1 Prepare the edges of the test specimens so as to eliminate all sheared or cold worked metal, except for cold workingintroduced by stamping for identification. Shearing can,

40、in some cases, introduce residual stress that may cause considerable attack.Therefore, do not use specimens with sheared edges unless this effect is being evaluated. Finish the edges by machining orpolishing. The slight amount of cold work resulting from the machining process should not introduce se

41、rious error.6.3.2 The specimen metallurgical and surface condition should be similar to the application being modeled. In all cases, removesurface contamination, such as dirt, grease, oil and thick oxides, prior to weighing and exposure to the test environment (seePractice G1).6.3.3 The effect of da

42、mage areas on coated specimens may be of interest. In this circumstance, artificially introduce uniformdamages, similar in size to the expected field damage. Some methods of applying standardized mechanical damage to coatedspecimens are presented in Test Method D1654.6.3.4 Introduce a specimen ident

43、ification system that will endure throughout the test period. Edged notches, drilled holes,stamped numbers, and tags are some of the methods used for identification. The identification system must not induce corrosionattack in any way.6.4 Number of Specimens:6.4.1 The number of scheduled periodic sp

44、ecimen removals during the test should include duplicate and, preferably, triplicatespecimens for any given test period to determine the variability in the corrosion behavior. The effect of the number of replicationson the evaluation of the results is set forth in Practice G16.6.4.2 If the test spec

45、imens are made of galvanically coupled dissimilar metals, control specimens should also be tested toprovide corrosion rates of the individual metals and alloys (without coupling) for comparison. These specimens should be of thesame alloys, shapes, sizes, surface, and metallurgical condition as the m

46、aterials in the couple.G162 1837. Test Procedure7.1 Weigh SpecimenWhen the objective of the test is to determine mass loss, the pre-exposure initial weight of the specimenshall be taken and recorded.7.2 Test AssemblyIntroduce the test soil into the container no less than 2 cm from the top of the con

47、tainer. Bury the specimen(or specimens) within the soil. The specimen should not contact the container and should be completely buried unless the effectof partial burial is desired (see Fig. 1).7.2.1 The corrosion behavior of metals in soil is influenced by the compaction of the soil around the meta

48、l and the effect of porestructure of the soil on the oxygen transport to the metal surface. Therefore, when simulating site conditions, the test soil shall becompacted appropriately.in a manner to approximate as close as possible the environment of interest. Care shall be taken tomaintain complete c

49、ontact of all surfaces of the test specimen with the soil. For corrosion testing, compaction is typically moreof an issue for non-saturated soil environments than for saturated soil environments. For testing in non-saturated soil environments,evaluation of the soil compaction utilizing such methods as described in Test Methods D698 may be considered.7.2.2 Space the specimens (if more than one is buried within a container) such that a minimum of 40 cm3 of test soil surroundseach square centimetrecentimeter of exposed surface area.7.2.3 The appropriate electrolyte