1、Designation: E 1253 07Standard Guide forReconstitution of Irradiated Charpy-Sized Specimens1This standard is issued under the fixed designation E 1253; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber 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 guide covers procedures for the reconstitution offerritic pressure boundary steels used in nuclear power plantapplications, Type A
3、Charpy (Test Methods E23) specimensand specimens suitable for testing in three point bending inaccordance with Test Methods E 1921 or E 1820. Materialsfrom irradiation programs (principally broken specimens) arereconstituted by welding end tabs of similar material ontoremachined specimen sections th
4、at were unaffected by theinitial test. Guidelines are given for the selection of suitablespecimen halves and end tab materials, for dimensional con-trol, and for avoidance of overheating the notch area. Acomprehensive overview of the reconstitution methodologiescan be found in Ref (1).21.2 The value
5、s stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 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 saf
6、ety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3E23 Test Methods for Notched Bar Impact Testing ofMetallic MaterialsE 185 Practice for Design of Surveillance Programs forLight-Water Moderated Nuclear Power Re
7、actor VesselsE 220 Test Method for Calibration of Thermocouples ByComparison TechniquesE 1820 Test Method for Measurement of Fracture Tough-nessE 1921 Test Method for Determination of Reference Tem-perature, To, for Ferritic Steels in the Transition RangeE 2215 Practice for Evaluation of Surveillanc
8、e Capsulesfrom Light-Water Moderated Nuclear Power Reactor Ves-sels3. Significance and Use3.1 Practice E 185 defines the minimum requirements forlight-water reactor surveillance program Charpy V-notch speci-mens and Practice E 2215 describes the evaluation of testspecimens from surveillance capsules
9、. It may be desirable toextend the original surveillance program beyond availablespecimens for plant aging management issues, such as plantlicense renewal, to better define existing data, or to determinefracture toughness of a material when no standard fracturetoughness test specimens are available.
10、 The ability to reconsti-tute the broken halves of existing specimens can provide suchdata.3.2 Charpy-sized specimens are typically machined fromvirgin material, that is, material not previously mechanicallytested. There are occasions that exist when either (1) no fullsize specimen blanks are availa
11、ble or (2) the material availablewith the desired history (such as having been subjected toirradiation) is not sufficient for the machining of full-sizespecimens, or both.3.3 An approach to this problem, which is addressed in thisguide, is to fabricate new specimens using the broken halves ofpreviou
12、sly irradiated and tested specimens or other materialirradiated for this purpose. In this guide, the central segment ofeach new specimen utilizes a broken half of a previously testedspecimen and end tabs that are welded to the central segment,or the central section may simply be a piece of virgin ma
13、terialshorter than a Charpy-sized specimen. While specificallyaddressing reconstitution of irradiated pressure vessel steel,this guide can also provide guidance for reconstitution ofCharpy-sized specimens for other situations involving materialavailability.4. Reconstitution Technique4.1 Welding Proc
14、ess:1This guide is under the jurisdiction of ASTM Committee E10 on NuclearTechnology and Applications and is the direct responsibility of SubcommitteeE10.02 on Behavior and Use of Nuclear Structural Materials.Current edition approved Feb. 1, 2007. Published March 2007. Originallyapproved in 1993. La
15、st previous edition approved in 1999 as E 1253-99.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards
16、 volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.1 Any welding process may be chosen, provided that theheat input and dimensional constraints, as
17、 given in this guide,can be achieved. Work to date has indicated successful resultswith stud welding (2), electron beam welding (3,4), andprojection welding (5).4.2 Specimen Preparation:4.2.1 The specimen insert used for reconstitution and itsorientation shall be identified such that it can be trace
18、d to theoriginal specimen. Fig. 1 illustrates the components of thereconstituted specimen and defines several terms used in thefollowing discussion. The central test section of the insert liesbetween the heat-affected zones (HAZ) created by the recon-stitution welds. Within this central test section
19、, the temperatureduring reconstitution welding shall not exceed the irradiationtemperature in a 10-mm region centered about the notch.4.2.2 Each end face of the specimen insert and the selectedextension tabs shall be prepared as required by the particularwelding method selected.4.2.3 If comparable d
20、ata between the original and reconsti-tuted tests are required, then the orientation of the reconstitutedspecimen and the original specimen must be identical.4.2.4 The strength and the material type of the end tabsshould be similar to the specimen insert. This can be important,especially in the case
21、 of irradiated (highly hardened) materials.Strength or hardness and material type for the end tabs andcentral insert shall be documented. Differences within a de-fined range were shown not to influence the test results (6). Theuse of oversized tabs and subsequent machining is permitted.4.2.5 It is i
22、mportant to ensure that the plastic deformationbeneath the notch, produced when the reconstituted specimenis tested, will occur entirely within previously undeformedmaterial in the central test section. The following guidelinesare provided to meet this objective:4.2.5.1 To ensure that the specimen i
23、nsert volume, subjectedto plastic deformation during the subsequent testing, is free ofprior plastic deformation, sufficient material shall be removedfrom the fractured end of the broken specimen half. Someplastic deformation on either end of the original insert can beaccepted if it is outside the c
24、entral 10 mm (0.40 in.) portion.4.2.5.2 The minimum length of the specimen insert shall be18.0 mm (0.56 in.) unless the conditions stipulated in 4.2.5.3are fulfilled.4.2.5.3 This dimensional requirement of 18 mm is based onCharpy impact specimens tested on the upper shelf (where theplastic zone is m
25、aximum) and fabricated with the stud weldingreconstitution technique (where heat input and HAZ sizes aremaximum). Reconstituted specimens tested in the lower tran-sition range or on the lower shelf in accordance with TestMethods E23and reconstituted precracked specimens tested inaccordance with Test
26、 Method E 1921 will have much smallerplastic zones. Other reconstitution techniques, such as electronbeam welding, produce HAZs smaller than stud welding.Therefore, this dimensional requirement may be relaxed, if itcan be experimentally or analytically shown that the plasticdeformation zone in subse
27、quent testing will not extend into theheat affected zones produced by reconstitution and the require-ment of 4.4.1 is met (see Fig. 1). Test programs have shownacceptable Charpy results using shorter inserts (7-9).4.2.6 Many weld specimens contain base material and HAZ.Therefore, care shall be taken
28、 such that the heat-affected zoneof an original weld is not contained in the central test sectionof the reconstituted specimen (see Fig. 1). HAZ specimens canbe used as an additional source of weld or base material forinserts. In an inhomogeneous specimen insert, which containsbase or weld material
29、and HAZ, only the target test materialshall be contained in the central 10 mm (0.40 in.) portion.4.3 FixturingThe fixture design will depend upon the typeof welding process chosen for the welding operation. Asuccessful design will maintain dimensional control, minimizeheat input to the central test
30、section, and satisfy designconstraints associated with remote handling.4.4 Heat Input:4.4.1 To preclude irradiation damage annealing, heat inputduring welding shall be controlled such that no part of thevolume of the central 10-mm (0.40-in.) portion of the recon-stituted Charpy-sized specimen exceed
31、s the prior metal irra-diation temperature at any time during welding (see Fig. 1).This requirement can be relaxed if it can be shown that theplastic deformation zone in subsequent testing will not extendpast the zone where irradiation temperature is exceeded.4.4.2 To demonstrate that the temperatur
32、e requirement of4.4.1 is met for a given selection of welding parameters,temperature records shall be made daily, using thermocouples,during welding a set of Charpy-sized specimens. Such ademonstration is preferably made on dummy inserts withthermocouples that are welded or soldered in the mid-thick
33、nessof the dummy insert. If surface thermocouples are used, then asurface-to-center temperature correction must be made and thebasis of the correction documented.Acomprehensive overviewof the important issues in temperature measurements can befound in Ref (10).4.4.3 Thermocouples used in maximum tem
34、perature deter-mination shall be calibrated in accordance with Test MethodE 220.NOTE ANo plastic deformation from previous testing is permitted in the centraltestsection.Temperatureduringweldinginthe10-mmcentraltestsectionshallnotexceed the irradiation temperature.FIG. 1 Schematic of a Reconstituted
35、 Charpy SpecimenE12530724.5 Dimensional RequirementsDimensional control of re-constituted specimens shall be in accordance with the subse-quent test method (Test Method E23, E 1820,orE 1921). Ifthe user of this guide is unable to produce specimens that meetthe applicable test method dimensional requ
36、irements, then theuser shall justify using specimens with dimensions exceedingthe test method requirements. All deviations from the testmethod shall be documented and reported with the data. Ref(6) describes a study on the effects of some dimensionaldeviations.4.6 Safety PrecautionsThe reconstitutio
37、n procedures gen-erally involve handling irradiated specimen materials, and theuser of this guide is responsible for establishing appropriatesafety practices, which is outside the scope of this guide.5. Qualification of Reconstitution Technique5.1 The welding process and fixture design shall be qual
38、i-fied prior to reconstituting specimens of interest, using mate-rials of known impact properties. It shall be demonstratedduring qualification that the following acceptance criteria havebeen achieved:5.1.1 The temperature of the central 10-mm (0.40-in.)portion of the specimen shall not exceed, at a
39、ny time during thewelding process, a temperature that affects its metallurgicalcondition unless it can be shown that the plastic deformationzone in subsequent testing will not extend past the zone wherethe metallurgical condition has been affected. In the case ofirradiated specimens, the prior irrad
40、iation temperature must notbe exceeded in the central 10-mm portion of the specimen.5.1.2 The welding procedure shall routinely produce weldquality such that fracture is at the notch of the reconstitutedspecimen and not in the reconstitution weldment. Examples ofa weld qualification methodology can
41、be found in Ref (11).5.1.3 The reconstitution technique shall yield properties(41-J and 68-J transition temperature and upper shelf energy orreference temperature, To, or fracture toughness, as appropri-ate) equivalent to those of original testing. It is recommendedthat the reconstituted specimens f
42、or technique qualification betested at temperatures identical to the original test temperaturesso that data can be directly compared.5.1.4 The material used for reconstitution qualification shallbe selected such that the properties of this material encompassthe properties of the material of interest
43、.6. Documentation6.1 Specimen Reconstitution Record:6.1.1 Test material, test material strength or hardness, ori-gin, location, and orientation.6.1.2 Reconstituted specimen identity.6.1.3 Irradiation temperature and fast neutron fluence (E 1.0 MeV).6.1.4 Welding process parameters.6.1.5 Extension ta
44、b material and strength or hardness.6.1.6 Statement of conformance with dimensional control tothe subsequent test method (Test Method E23, E 1820 orE 1921).6.2 Additional DocumentationThe following informationshall be available by reference to a suitable document.6.2.1 Process Qualification Informat
45、ion:6.2.1.1 Identities and nominal impact energies or KJcof thequalification specimens.6.2.1.2 Test temperature of the qualification specimens.6.2.1.3 Impact energy, lateral expansion, and fracture ap-pearance, or KJc, of the qualification specimens as appropriate.6.2.1.4 Comparison of original and
46、reconstituted Charpycurves or comparison of the reference temperatures of theoriginal and reconstituted specimens.6.2.2 Heat Input Monitoring:6.2.2.1 Type of temperature measurement equipment.6.2.2.2 Number of temperature measurements and loca-tions.6.2.2.3 Details of temperature recording during th
47、e weldingcycles.6.2.2.4 Precision and bias of the temperature measuringsystem.6.2.2.5 Fixturing details.6.2.3 Welding Procedure.7. Keywords7.1 Charpy; impact energy; fracture toughness; nuclearpressure vessel surveillance; reconstitution; welding processREFERENCES(1) van Walle, E., “Reconstitution:
48、Where Do We Stand?,” Effects ofRadiation on Materials: 17th International Symposium on Materials,ASTM STP 1270, Davis S. Gelles, Randy K. Nanstad, Arvind S.Kumar, and Edward A. Little, Eds., American Society for Testing andMaterials, 1996.(2) Perrin, J. S., Wullaert, R.A., McConnell, P., Server, W.
49、L., and Fromm,E. A., “Reconstituted Charpy Impact Specimens,” EPRI ReportNP2759, December 1982.(3) Burch, P. R., “A Pilot Experiment to Determine the Feasibility ofReconstituting Irradiated Charpy V Specimens,” ASTM Journal ofTesting and Evaluation, September 1983.(4) Van Der Sluys, W.A., “Constructing Compound Charpy Specimens byE. B. Welding,” Babcock and Wilcox, Alliance, OH, January 1979.(5) Shogan, R. P., Yanichko, S. E., and Galloway, W., “The Use ofReconstituted Charpy Specimens to Extend R. E. Ginna ReactorPressure Surveillance Data,” Nuclear Technology, Vol 72, March 1986.
