1、Designation: E 531 76 (Reapproved 2007)Standard Practice forSurveillance Testing of High-Temperature NuclearComponent Materials1This standard is issued under the fixed designation E 531; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers procedures for specimen testing toestablish changes occurring in the mechanical
3、properties due toirradiation and thermal effects of nuclear component metallicmaterials where these materials are used for high temperatureapplications above 370C (700F).2. Referenced Documents2.1 ASTM Standards:2A 370 Test Methods and Definitions for Mechanical Testingof Steel ProductsE3 Guide for
4、Preparation of Metallographic SpecimensE8 Test Methods for Tension Testing of Metallic MaterialsE21 Test Methods for Elevated Temperature Tension Testsof Metallic MaterialsE23 Test Methods for Notched Bar Impact Testing ofMetallic MaterialsE29 Practice for Using Significant Digits in Test Data toDet
5、ermine Conformance with SpecificationsE45 Test Methods for Determining the Inclusion Contentof SteelE112 Test Methods for Determining Average Grain SizeE 139 Test Methods for Conducting Creep, Creep-Rupture,and Stress-Rupture Tests of Metallic MaterialsE 185 Practice for Design of Surveillance Progr
6、ams forLight-Water Moderated Nuclear Power Reactor VesselsE 206 Discontinued 1988; Definitions of Terms Relating toFatigue Testing and the Statistical Analysis of FatigueData; Replaced by E 11503E 261 Practice for Determining Neutron Fluence, FluenceRate, and Spectra by Radioactivation TechniquesE 3
7、99 Test Method for Linear-Elastic Plane-Strain FractureToughness KIcof Metallic MaterialsE 453 Practice for Examination of Fuel Element CladdingIncluding the Determination of the Mechanical PropertiesE 482 Guide for Application of Neutron Transport Methodsfor Reactor Vessel Surveillance, E706 (IID)E
8、 844 Guide for Sensor Set Design and Irradiation forReactor Surveillance, E 706(IIC)3. Significance and Use3.1 The requirements contained herein can be used as abasis for establishing conditions for safe operation of criticalcomponents. The requirements provide for general plant as-sessment and veri
9、fication that materials meet design criteria.The test specimens and procedures presented in this practiceare for guidance when establishing a surveillance program.3.2 This practice for high-temperature materials surveil-lance programs is used when nuclear reactor componentmaterials are monitored by
10、specimen testing. Periodic testing isperformed through the service life of the components to assesschanges in selected material properties that are caused byneutron irradiation and thermal effects. The properties are thoseused as design criteria for the respective nuclear components.The extent of ma
11、terial property change caused by neutronirradiation depends on the composition and structure of theinitial material, its conditioning in component fabrication, aswell as the nature of the irradiation exposure. The need forsurveillance arises from a concern of specific material behaviorunder all irra
12、diation conditions including spectrum and rateeffects on material properties.4. Description of Term4.1 test specimena coupon or a piece of metal cut from alarger metal piece which is then formed to final size for testingto determine physical or mechanical properties.5. Test Specimens5.1 Pre-Exposure
13、 Material CharacterizationIt is impor-tant that test specimen materials be characterized prior toexposure and that the following should be considered as aminimum:1This recommended practice is under the jurisdiction of ASTM Committee E10on Nuclear Technology and Applications and is the direct respons
14、ibility ofSubcommittee E10.02 on Behavior and Use of Nuclear Structural Materials.Current edition approved June 1, 2007. Published July 2007. Originally approvedin 1975. Last previous edition approved in 2001 as E 53176(2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orco
15、ntact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.1.1 Pro
16、cess history, material designation, manufacturer,heat number, weld and fabrication procedures used, and heattreatment,5.1.2 Original location and orientation in the parent mate-rial,5.1.3 Specimen weight and dimensions,5.1.4 Metallographic characteristics (grain size, microstruc-ture, and inclusion
17、content established in accordance with TestMethods E45and E112),5.1.5 Chemical analysis results,5.1.6 All specimens shall be taken from the specifiedlocation and orientation specified in Test Methods and Defini-tions A 370 and Test Methods E8, and5.1.7 Mechanical properties including yield strength,
18、 tensilestrength, stress rupture life, creep strength, fatigue strength,and impact strength as a function of test temperature.5.1.8 The information described in 5.1.1-5.1.7 should bereported in a single document.5.2 Post Exposure Material CharacterizationAfter expo-sure, the following should be repo
19、rted:5.2.1 Observations from visual examination,5.2.2 Changes in specimen weight and dimensions,5.2.3 Metallographic characteristics (grain size, microstruc-ture, and inclusion content),5.2.4 Results of chemical analysis,5.2.5 Appropriate mechanical properties being surveyedincluding considerations
20、of changes in tensile strength, stress-to-rupture strength, creep strength, fatigue strength, impactstrength (control tests are recommended to be performedsimultaneously with the tests of exposed specimens to ensurethat deviations in test results can be attributed to the exposedspecimens environment
21、 and not to variations in testing meth-ods), and5.2.6 Optional quantitative examination of surface chemis-try and subsequent changes.5.2.7 Exposed test specimens should be cleaned in accor-dance with accepted cleaning procedures. (Refer to Subcom-mittee G01.08 for practices for preparing, cleaning,
22、and evalu-ating test specimens.)5.3 Specimen PreparationTest specimens shall be stan-dard recommended specimens where possible as described inTest Methods E 8, E 21 and E 23 and Practice E 139. The useof the word specimen or words test specimen as used in thispractice is described in Section 4.5.3.1
23、 The test area of a specimen (for example, Charpynotch, reduced section of a fatigue specimen) may be leftunfinished if further environmental exposure prior to testing isanticipated.5.3.2 SizeIn general, due to the limited space available insurveillance capsules the smaller sizes of test specimens a
24、rerecommended. Where it is not possible to use specimens of therecommended size, the least deviation possible from recom-mended sizes should be adhered to. Non-standard specimensshall be evaluated prior to use as surveillance specimens toensure that test results from the use of non-standard specimen
25、scan be correlated with test results from specimens of recom-mended size. In the event that non-standard specimens are usedfor surveillance specimens, the archive, base line, and thermalcontrol specimens shall be identical with the surveillancespecimens.5.3.3 Surface ConditionTest specimens where su
26、rfacecondition is critical to the test results should not be finishmachined in such critical areas (Charpy notch, fatigue speci-men test area, surface of density change sample) until just priorto test. Specimens should be oversized to allow for removal ofat least 0.1 mm of surface prior to test. Whe
27、re possible, testspecimens with the exception of weight change specimensshall be encapsulated in an inert environment so as to deter-mine only the effect of neutron irradiation and temperature onmechanical or physical properties. It is recognized the integrityof the encapsulation may be breached in
28、some cases duringlong exposure and an allowance for final machining even of theencapsulated specimens should be considered. This will ensurea meaningful comparison between baseline and exposed speci-mens.5.3.4 Number of SpecimensThe number of specimensemployed for mechanical property testing should
29、be selected soas to include each critical component that varies significantly incomposition, processing, or in exposure conditions from simi-lar components. Specific recommendations as to number ofspecimens will be found in the respective specimen sections.At least four sets of specimens shall be in
30、cluded in eachsurveillance program.5.3.5 MaterialTest specimens shall be taken from thematerial used in component fabrication. The material shall beprocessed at the same time as the component or processed in afashion identical to the component surveyed. Weld and heat-affected zone test specimens sha
31、ll be taken from equivalentmaterial welded at the same time as the particular componentor equivalent material welded with the same welding param-eters. It is not necessary to include each heat or minorvariation, but only to select those receiving the highest expo-sure or those previously found to be
32、 most sensitive to neutronirradiation and temperature or those that can restrict theoperation of the reactor. Test specimens may be taken fromcomponents periodically removed from the reactor for otherreasons. These specimens can be used to provide supplementalsurveillance information. For this infor
33、mation to be meaningfula full characterization of the pre-exposure condition must beavailable along with measured exposure conditions.5.4 Tension Test SpecimensThe type and size of specimento be used shall conform to the smaller sizes as recommendedin Test Methods E8andE21. Either threaded or button
34、-headends will be acceptable. For plate or sheet specimens, pin endsas described in Test Methods E8 are recommended. Thelocation and orientation of test specimens shall be as defined inTest Methods E8or Test Methods and Definitions A 370,orinPractice E 185. Both base metal and weld metal specimens w
35、illbe taken. A set of tension specimens shall consist of three eachbase metal and weld metal.5.5 Creep and Stress-Rupture in SpecimensThe type andsize of specimen to be used shall be the same as those used fortension specimens except that button-head or pinned-endspecimens are recommended for high-t
36、emperature testing.Practice E 453 describes the attention that must be paid toE 531 76 (2007)2specimen alignment and dimensional tolerances. One set oftests shall be conducted at the operating temperature of thecomponent of interest. A set shall comprise a minimum of sixstress rupture tests at six d
37、ifferent stress levels. The stresslevels should be selected so that the time-to-rupture rangesfrom not less than 100 h to at least 3000 h. Creep strainmeasurements may be made if desired.5.6 Low-Cycle Fatigue SpecimensFor base metal the typeand size of specimen to be used may be the “hourglass” type
38、with threaded or button-head ends as shown in Fig. 1. For weldmetal specimens the uniform gage type may be used. Machin-ing and polishing of the test specimens shall be performed withcare so as to minimize the effects of specimen preparation onfatigue life. In the final stages of machining, material
39、 shall beremoved in the radial thickness amounts of 0.2 mm until 0.1mm remains. After exposure the final 0.075 mm shall beremoved by cylindrical grinding at no more than 0.005 mm perpass. The final 0.025 mm shall be buffed and finished with an0.2 m Ra(8 in. AA) surface roughness. After polishing, al
40、lremaining grinding and polishing marks shall be longitudinaland any circumferential grinding marks must be removed. Thefinished specimens shall be degreased in suitable solvent.Specimens to be exposed to liquid sodium shall not bedegreased in halogenated solvents. If surface observations areto be m
41、ade, the test specimen may be electropolished inaccordance with Methods E3. Test specimens that are suscep-tible to corrosion in room-temperature air shall be stored assoon as practicable after preparation in an inert dry gas orvacuum. A set of specimens shall consist of ten each of basemetal and we
42、ld metal.5.7 Swelling SpecimensThe swelling specimens shall beright circular cylinders 5.0 mm diameter and 10.0 mm long.The sharp-cornered specimens shall be finished by turning orgrinding and have a surface finish of 0.2 m Ra(8 in. AA).The specimens shall be degreased in suitable solvent and stored
43、in an inert gas or vacuum.5.8 Charpy Impact SpecimensThe specimens to be usedshall conform to the Charpy V-notch specimens recommendedin Test Methods E23. The notch shall not be formed prior toexposure as a surveillance specimen. The location and orien-tation of test specimens shall be as defined in
44、 Practice E 185and Test Methods and Definitions A 370. A set of specimensshall be made up of twelve each base metal, heat-affected zone,and weld metal.NOTE 1A = 0.2 m Ra(8 min AA).Metric Conversionmm in.0.3 0.016.35 0.2508.4 0.3312.68 0.49912.70 0.50019.1 0.7538.1 1.582.6 3.25FIG. 1 Standard Hour-Gl
45、ass Low Cycle Fatigue Specimen (Threaded Ends (a) and Button Head (b)E 531 76 (2007)36. Irradiation Conditions6.1 IntroductionThe intent of the section on irradiationconditions is to provide guidance on how to place surveillancesamples to obtain the desired irradiation conditions in terms oftemperat
46、ure, neutron flux, and neutron spectrum to ensure arealistic evaluation of the component that the surveillancespecimen is representing.6.2 Irradiation TemperatureIt is very important that ad-equate consideration be given to test specimens to ensure thatthey experience the correct temperature during
47、irradiation.Temperature must be controlled for the surveillance specimensto match as nearly as possible the temperature of the compo-nent being surveyed. When temperature variations arise be-cause of separation of the surveillance specimens from thecomponent, additional specimens should be included
48、in otherpositions which will cover a temperature range including thecomponent operating temperature. The irradiation temperatureshall be given and the method for determination shall bedocumented.6.3 Flux and Spectrum:6.3.1 The size of certain reactor components may introduceirradiation conditions th
49、at cover a wide range of neutron fluxesand spectra. Accordingly, surveillance irradiations carried outat locations other than exactly in contact with the component ofinterest will require consideration of the change in neutron fluxand spectrum between component and surveillance location.Frequently, surveillance specimens are placed such that theneutron flux is higher than at the component of interest; dueconsideration must then be given to changes in neutron energyspectrum when making such compromises.6.3.2 Also of considerable importance during elevated tem
