1、Designation: E696 07 (Reapproved 2013)Standard Specification forTungsten-Rhenium Alloy Thermocouple Wire1This standard is issued under the fixed designation E696; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. 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 specification covers the requirements for bare,solid conductor, tungsten and rhenium alloy thermoelementshaving diameters
3、 of 0.127 mm (0.005 in.) to 0.508 mm (0.020in.) supplied in matched pairs. These thermoelements shall besuitable for use either in bead-insulated, bare-wirethermocouples, or in compacted metal-sheathed, ceramic insu-lated thermocouple material or assemblies.1.2 This specification covers the thermoco
4、uple combina-tions of tungsten-3 % rhenium versus tungsten-25 % rhenium(W3Re/W25Re) and tungsten-5 % rhenium versus tungsten-26 % rhenium (W5Re/W26Re; Type C). All information ap-plies to both combinations unless otherwise noted.1.3 It is recognized that the alloys described are refractoryand are no
5、t suitable for use at high temperatures in oxidizingatmospheres. All tests and processes described herein must beperformed under conditions that are non-reactive to tungsten-rhenium alloys.1.4 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for in
6、formationonly.2. Referenced Documents2.1 ASTM Standards:2E8 Test Methods for Tension Testing of Metallic MaterialsE207 Test Method for Thermal EMF Test of Single Thermo-element Materials by Comparison with a Reference Ther-moelement of Similar EMF-Temperature PropertiesE220 Test Method for Calibrati
7、on of Thermocouples ByComparison TechniquesE230 Specification and Temperature-Electromotive Force(EMF) Tables for Standardized ThermocouplesE344 Terminology Relating to Thermometry and Hydrom-etryE452 Test Method for Calibration of Refractory Metal Ther-mocouples Using a Radiation ThermometerE988 Te
8、mperature-Electromotive Force (EMF) Tables forTungsten-Rhenium Thermocouples (Withdrawn 2011)3E1751 Guide for Temperature Electromotive Force (EMF)Tables for Non-Letter Designated Thermocouple Combi-nations (Withdrawn 2009)33. Terminology3.1 Definitions:3.1.1 For definitions used in this standard, s
9、ee TerminologyE344.3.2 Definitions of Terms Specific to This Standard:3.2.1 dope, vtin this specification, to add potassium,silicon and aluminum compounds or other volatile substancesto the alloy powders during the preparation to produce a ductilewire. See NASA CR-72884.43.2.1.1 DiscussionSome alloy
10、 powders are doped.3.2.2 lot, na quantity of wire processed or heat treated asa single continuous length and identified uniquely.4. Ordering Information4.1 A purchase order for thermocouple material conformingto this specification shall specify the following:4.1.1 Thermocouple Wire CompositionMay be
11、 W3Re/W25Re or W5Re/W26Re.4.1.2 Wire SizeSpecify size with each order.4.1.3 Wire LengthSpecify total amount of each wire andminimum continuous length.4.1.4 Thermocouple CalibrationCalibration will be inaccordance with Section 5.1.4 unless otherwise specified.4.1.5 Supplementary RequirementsSee the S
12、upplementaryRequirements section of this specification.4.1.6 Instructions for Spooling, Packaging, and LabelingPackaging will be in accordance with Section 10 unlessotherwise specified.4.1.7 Tests and Certifications Required from theProcessorCertification will be in accordance with Section 9unless o
13、therwise specified.1This specification is under the jurisdiction of ASTM Committee E20 onTemperature Measurement and is the direct responsibility of Subcommittee E20.04on Thermocouples.Current edition approved May 1, 2013. Published May 2013. Originallyapproved in 1979. Last previous edition approve
14、d in 2007 as E696 07. DOI:10.1520/E0696-07R13.2For referenced ASTM standards, 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 appro
15、ved version of this historical standard is referenced onwww.astm.org.4NASA CR-72884, “Some Studies on Behavior of W-Re Thermocouple Mate-rials at High Temperatures.” Available from National Aeronautics and SpaceAdministration, 400 Maryland Ave. S.W., Washington, DC 20546.Copyright ASTM International
16、, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Materials and Manufacture5.1 Thermocouple Wire:5.1.1 GeneralThe thermoelements shall be tungsten-3 %rhenium and tungsten-25 % rhenium or tungsten-5 % rheniumand tungsten-26 % rhenium (Type C), as indicated on th
17、epurchase order.5.1.2 Physical:5.1.2.1 The diameter of each wire shall be within 60.01 mm(0.0005 in.) of the ordered size for 0.5 mm (0.02 in.) diameterwire and smaller. The diameter of each wire shall be uniformend-to-end to within 0.01 mm (0.0005 in.) for 0.5 mm (0.02in.) diameter wire and smaller
18、.5.1.2.2 The wires shall be solid, round, smooth and be freeof weld joints, slivers, kinks, pits or nicks exceeding 5 % ofdiameter.5.1.2.3 The wire surface shall be uniformly clean and free ofdiscoloration.5.1.2.4 Mechanical or optical methods may be used toverify the requirements of 5.1.2.1, 5.1.2.
19、2, and 5.1.2.3.5.1.3 Mechanical:5.1.3.1 The wires shall withstand, at a temperature of 20 to35 C (68 to 95 F), wrapping five turns around a mandrel fivetimes the diameter of the wire without breaking or splitting.5.1.3.2 The tests shall be made on at least one specimenfrom each end of each lot of wi
20、re.5.1.4 Thermoelectric:5.1.4.1 The emf versus temperature characteristics of thematched thermoelements shall be determined using proceduresdescribed in Test Methods E207, E220,orE452.5.1.4.2 The emf versus temperature relationship of thematched pair of thermoelements shall comply with the valuessho
21、wn in Guide E1751 for W3Re/W25Re or SpecificationE230 for Type C (W5Re/W26Re).5.1.4.3 The initial calibration tolerance shall be in accor-dance with Table 1 (W3Re/W25Re). or Specification E230(W5Re/W26Re), as appropriate.5.2 Composition:5.2.1 Positive thermoelement:5.2.1.1 The positive thermoelement
22、 for the W3Re/W25Recombination shall have a nominal composition of 97 % tung-sten and 3 % rhenium.5.2.1.2 The positive thermoelement for the W5Re/W26Recombination shall have a nominal composition of 95 % tung-sten and 5 % rhenium.5.2.1.3 The positive thermoelement shall be doped to pro-vide desirabl
23、e grain structure and workability and maintainductility after high temperature use.5.2.2 Negative thermoelement:5.2.2.1 The negative thermoelement for the W3Re/W25Recombination shall have a nominal composition of 75 % tung-sten and 25 % rhenium.5.2.2.2 The negative thermoelement for the W5Re/W26Reco
24、mbination shall have a nominal composition of 74 % tung-sten and 26 % rhenium.6. Lot Identification6.1 Thermocouple wires, test results and certifications shallbe identified by manufacturers lot number.7. Lot Designation7.1 A vendor who purchases wire from processors forrepackaging and resale shall
25、supply, for each spool, the wireprocessors name, lot number and certification to the customer.8. Extension Wires8.1 Due to the high cost of tungsten-rhenium alloys, todifficulties encountered in obtaining long continuous lengths ofthese alloys and to inherent problems in applications whereductility
26、is important, many users find it advantageous to usecompensating extension wires made of base metal alloys.8.2 Information on upper temperature limits and the suppli-ers guaranteed limits of error for currently available compen-sating extension wires for W3Re/W25Re can be found in Table2. Informatio
27、n on upper temperature limits and the suppliersguaranteed limits of error for currently available compensatingextension wires for W5Re/W26Re can be found in Specifica-tion E230.9. Certification9.1 The processor shall supply a certificate with each orderstating the wire composition, size, lot identif
28、ication and cali-bration information.TABLE 1 Initial Calibration Tolerances and Suggested Temperature Range for W3Re/W25Re ThermocouplesATemperature Range Initial Calibration ToleranceThermocouple Type C F C (whichever is greater) FW3Re/W25Re 0 to 2315 C 32 to 4200 4.4 or 1 % Note 3ACautionUsers sho
29、uld be aware that certain characteristics of thermocouple materials including calibration may change in time with use; consequently, test resultsobtained at time of manufacture may not necessarily apply throughout an extended period of use.NOTE 1Initial calibration tolerances in this table apply to
30、new thermocouple wire, normally in the size range of 0.127 mm (0.005 in.) to 0.508 (0.020in.) mm in diameter (No. 36 to 24 AWG) and used at temperatures not exceeding the suggested upper temperatures of Table 1. If used at highertemperatures these initial calibration tolerances may not apply.NOTE 2I
31、nitial calibration tolerances apply to new wire as delivered to the user and do not allow for calibration drift during use. The magnitude ofsuch changes depends on such factors as wire size, temperature, time of exposure and environment.NOTE 3The F tolerance is 1.8 times larger than the C tolerance
32、at the equivalent C temperature. Note particularly that the percentage toleranceonly applies to the temperature that is expressed in C.NOTE 4Tables 1 and 2 describe suggested upper temperature limits for the thermocouple and extension wires. These limits apply to protectedthermocouples, that is, the
33、rmocouples in atmospheres that are non-reactive to the alloys being used.E696 07 (2013)210. Packaging and Package Marking10.1 Wires typically will be supplied on spools of a nominal100 mm (4 in.) diameter core and boxed individually, unlessotherwise requested. Each spool shall be marked to identify
34、thewire composition, diameter, quantity, processors name, spooldesignation and customers purchase order number in a mannerto identify the pair of wires to be used to form a thermocouplemeeting the calibration requirement.11. Keywords11.1 rhenium; thermocouple; thermoelement; tungstenSUPPLEMENTARY RE
35、QUIREMENTSThe following supplementary requirements shall apply only when specified by the purchaser in thepurchase order or contract.S1. MechanicalS1.1 The wires shall have an elongation measured at atemperature in the range of 20 to 35 C (68 to 95 F) of at least12 % as measured over a 50 mm (2 in.)
36、 gauge length.S1.2 Elongation shall be determined in accordance with TestMethods E8 using a rate of 0.2 mm/mm/min. (0.2 in./in./min.)maximum and a 50 mm (2 in.) gauge length.S1.3 The tests shall be made on at least one specimen fromeach end of each lot of wire.S2. ThermoelectricS2.1 The wires shall
37、be thermoelectrically homogeneous sothat when joined to form a thermocouple whose measuringjunction and reference junction are held at constanttemperatures, any short-term (less than 1 h) change in thetemperature profile along the wire within the range from 0 to1000 C (32 to 1832 F) will not produce
38、 a change in thethermocouple output signal of more than 100 V.S3. ElectricalS3.1 A dc resistance measurement may be used to verifymechanical integrity of tungsten-rhenium alloy wires havingdiameters of 0.125 mm (0.005 in.) or larger. Defects cited in5.1.2.2 can cause high local resistance in tungste
39、n alloy wires.S3.2 A dc resistance measurement at 20 C (68 F) shall bemade on an accurately measured reference length of eachthermoelement using an instrument and range to yield 61%accuracy to derive a resistance per meter or foot. The wire sizeof the reference length and test pieces of known, pract
40、icallengths should be within 0.005 mm (0.0002 in.) of each other.S3.3 The resistance measurement taken according to 12.3.2shall be compared to the dc resistance measurements of eachmeasured full length of wire.S3.4 The full length resistance per unit length (ohms permeter or foot) of each of the tes
41、t lengths shall be within 10 %of the value obtained from the reference length.NOTE S1The resistivity of W25Re and that of W26Re is more thandouble that of either W3Re or W5Re, and all of these alloys have hightemperature coefficients of resistance.ASTM International takes no position respecting the
42、validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is
43、subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Head
44、quarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This sta
45、ndard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or s
46、erviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 2 Initial Calibration Tolerances and Suggested Temperature Ranges for Type W3Re/W25Re Thermocouple CompensatingExt
47、ension WiresTemperature RangeDesignation C F Standard Tolerance300P(+) / 300N(-)A0 to 330 32 to 625 0.125mV203(+) / 225(-)B0 to 260 32 to 500 0.110 mVA97.7Ni Bal Cr, Al, and Si versus 96Ni, 4W; U.S. Patent 3,502,510 assigned to Engelhard Industries.B90Ni, 10Cr versus 98Ni, 2Cr; Designation of Hoskins Mfg.E696 07 (2013)3
