EN 61788-19-2014 en Superconductivity - Part 19 Mechanical properties measurement - Room temperature tensile test of reacted Nb3Sn composite superconductors.pdf

1、BSI Standards PublicationSuperconductivityPart 19: Mechanical properties measurement Room temperature tensile test of reacted Nb3Sn composite superconductorsBS EN 61788-19:2014National forewordThis British Standard is the UK implementation of EN 61788-19:2014. It isidentical to IEC 61788-19:2013.The

2、 UK participation in its preparation was entrusted to TechnicalCommittee L/-/90, Super Conductivity.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are respo

3、nsible for its correct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 72866 2ICS 29.050; 77.040.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theS

4、tandards Policy and Strategy Committee on 28 February 2014.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 61788-19:2014EUROPEAN STANDARD EN 61788-19 NORME EUROPENNE EUROPISCHE NORM February 2014 CENELEC European Committee for Electrotechnical Standardization Co

5、mit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2014 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61788-19:2014 E

6、 ICS 29.050; 77.040.10 English version Superconductivity - Part 19: Mechanical properties measurement - Room temperature tensile test of reacted Nb3Sn composite superconductors (IEC 61788-19:2013) Supraconductivit - Partie 19: Mesure des proprits mcaniques - Essai de traction temprature ambiante des

7、 supraconducteurs composites de Nb3Sn mis en raction (CEI 61788-19:2013) Supraleitfhigkeit - Teil 19: Messung der mechanischen Eigenschaften - Zugversuch von reagierten Nb3Sn-Verbundsupraleitern bei Raumtemperatur (IEC 61788-19:2013) This European Standard was approved by CENELEC on 2013-12-24. CENE

8、LEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on a

9、pplication to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN

10、-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary

11、, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 61788-19:2014EN 61788-19:2014 - 2 - Foreword The text of document 90/328/FDIS, future edition 1 of

12、 IEC 61788-19, prepared by IEC/TC 90 “Superconductivity“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61788-19:2014. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standa

13、rd or by endorsement (dop) 2014-09-24 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-12-24 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be

14、held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61788-19:2013 was approved by CENELEC as a European Standard without any modification. BS EN 61788-19:2014- 3 - EN 61788-19:2014 Annex ZA (normative) Normative references to

15、international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edit

16、ion of the referenced document (including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60050 series International Electrotechnical Vocabulary - - ISO 37

17、6 - Metallic materials - Calibration of force-proving instruments used for the verification of uniaxial testing machines EN ISO 376 - ISO 6892-1 - Metallic materials - Tensile testing - Part 1: Method of test at room temperature EN ISO 6892-1 - ISO 7500-1 - Metallic materials - Verification of stati

18、c uniaxial testing machines - Part 1: Tension/compression testing machines - Verification and calibration of the force-measuring system EN ISO 7500-1 - ISO 9513 - Metallic materials - Calibration of extensometer systems used in uniaxial testing EN ISO 9513 - BS EN 61788-19:2014 2 61788-19 IEC:2013 C

19、ONTENTS INTRODUCTION . 7 1 Scope 8 2 Normative references 8 3 Terms and definitions 8 4 Principles 10 5 Apparatus 10 5.1 General 10 5.2 Testing machine. 10 5.3 Extensometer . 10 6 Specimen preparation 10 6.1 General 10 6.2 Length of specimen 10 6.3 Removing insulation . 11 6.4 Determination of cross

20、-sectional area (S0). 11 7 Testing conditions . 11 7.1 Specimen gripping . 11 7.2 Setting of extensometer . 11 7.3 Testing speed 11 7.4 Test . 11 8 Calculation of results . 12 8.1 Modulus of elasticity (E) . 12 8.2 0,2 % proof strength (Rp0,2-0 and Rp0,2-U) 13 9 Uncertainty of measurand 13 10 Test r

21、eport . 13 10.1 Specimen . 13 10.2 Results 14 10.3 Test conditions 14 Annex A (informative) Additional information relating to Clauses 1 to 10 16 A.1 Scope 16 A.2 Extensometer . 16 A.2.1 Double extensometer 16 A.2.2 Single extensometer . 17 A.3 Optical extensometers . 18 A.4 Requirements of high res

22、olution extensometers . 19 A.5 Tensile stress Relasticmaxand strain Aelasticmax20 A.6 Functional fitting of stress-strain curve obtained by single extensometer and 0,2 % proof strength (Rp0,2-F) 21 A.7 Removing insulation . 22 A.8 Cross-sectional area determination 22 A.9 Fixing of the reacted Nb3Sn

23、 wire to the machine by two gripping techniques . 22 A.10 Tensile strength (Rm) 23 A.11 Percentage elongation after fracture (A) 24 A.12 Relative standard uncertainty . 24 A.13 Determination of modulus of elasticity E0. 26 BS EN 61788-19:201461788-19 IEC:2013 3 A.14 Assessment on the reliability of

24、the test equipment 27 A.15 Reference documents 27 Annex B (informative) Uncertainty considerations 28 B.1 Overview 28 B.2 Definitions 28 B.3 Consideration of the uncertainty concept . 28 B.4 Uncertainty evaluation example for TC 90 standards 30 B.5 Reference documents of Annex B . 31 Annex C (inform

25、ative) Specific examples related to mechanical tests 33 C.1 Overview 33 C.2 Uncertainty of the modulus of elasticity 33 C.3 Evaluation of sensitivity coefficients . 34 C.4 Combined standard uncertainties of each variable . 35 C.5 Uncertainty of 0,2 % proof strength Rp0,238 Bibliography 43 Figure 1 S

26、tress-strain curve and definition of modulus of elasticity and 0,2 % proof strengths for Cu/Nb3Sn wire . 15 Figure A.1 Light weight ultra small twin type extensometer 16 Figure A.2 Low mass averaging double extensometer 17 Figure A.3 An example of the extensometer provided with balance weight and ve

27、rtical specimen axis . 18 Figure A.4 Double beam laser extensometer 19 Figure A.5 Load versus displacement record of a reacted Nb3Sn wire . 20 Figure A.6 Stress-strain curve of a reacted Nb3Sn wire . 21 Figure A.7 Two alternatives for the gripping technique. 23 Figure A.8 Details of the two alternat

28、ives of the wire fixing to the machine . 23 Figure C.1 Measured stress-strain curve 33 Figure C.2 Stress-strain curve . 39 Table A.1 Standard uncertainty value results achieved on different Nb3Sn wires during the international round robin tests 25 Table A.2 Results of ANOVA (F-test) for the variatio

29、ns of E0. 26 Table B.1 Output signals from two nominally identical extensometers 29 Table B.2 Mean values of two output signals . 29 Table B.3 Experimental standard deviations of two output signals 29 Table B.4 Standard uncertainties of two output signals 30 Table B.5 Coefficient of Variations of tw

30、o output signals 30 Table C.1 Load cell specifications according to manufacturers data sheet. 35 Table C.2 Uncertainties of displacement measurement 36 Table C.3 Uncertainties of wire diameter measurement 37 Table C.4 Uncertainties of gauge length measurement 37 Table C.5 Calculation of stress at 0

31、% and at 0,1 % strain using the zero offset regression line as determined in Figure C.1 (b) . 38 Table C.6 Linear regression equations computed for the three shifted lines and for the stress strain curve in the region where the lines intersect 40 BS EN 61788-19:2014 4 61788-19 IEC:2013 Table C.7 Cal

32、culation of strain and stress at the intersections of the three shifted lines with the stress strain curve 40 Table C.8 Measured stress versus strain data and the computed stress based on a linear fit to the data in the region of interest 41 BS EN 61788-19:201461788-19 IEC:2013 7 INTRODUCTION The Cu

33、/Nb3Sn superconductive composite wires are multifilamentary composite materials. They are manufactured in different ways. The first method is the bronze route, where fine Nb / Nb alloy filaments are embedded in a bronze matrix, a barrier and a copper stabilizer. The second is the internal-tin method

34、, where fine multifilaments are composed with copper matrix including Sn reservoirs, a barrier, and a copper stabilizer. The third is the powder-in-tube method, where Nb / Nb alloy tubes are filled with Sn rich powders and are embedded in a Cu stabilizing matrix. Common to all types of Nb3Sn composi

35、te wires is that the superconducting A15 phase Nb3Sn has been formed at final wire dimension by applying one or more heat treatments for several days with a temperature at the last heat treatment step of around 640 C or above. This superconducting phase is very brittle and failure of filaments occur

36、s accompanied by the degradation of the superconducting properties. Commercial composite superconductors have a high current density and a small cross-sectional area. The major application of the composite superconductors is to build superconducting magnets. This can be done either by winding the su

37、perconductor on a spool and applying the heat treatment together with the spool afterwards (wind and react) or by heat treatment of the conductor before winding the magnet (react and wind). While the magnet is being manufactured, complicated stresses are applied to its windings. Therefore the react

38、and wind method is the minority compared to the wind and react manufacturing process. In the case that the mechanical properties should be determined in the unreacted, non-superconducting stage of the composite, one should also apply this standard or alternatively IEC 61788-6 (Superconductivity Part

39、 6: Mechanical properties measurement Room temperature tensile test of Cu/Nb-Ti composite superconductors). While the magnet is being energized, a large electromagnetic force is applied to the superconducting wires because of their high current density. In the case of the react and wind manufacturin

40、g technique, the winding strain and stress levels are very restricted. It is therefore a prerequisite to determine the mechanical properties of the superconductive reacted Nb3Sn composite wires of which the windings are manufactured. BS EN 61788-19:2014 8 61788-19 IEC:2013 SUPERCONDUCTIVITY Part 19:

41、 Mechanical properties measurement Room temperature tensile test of reacted Nb3Sn composite superconductors 1 Scope This part of IEC61788 covers a test method detailing the tensile test procedures to be carried out on reacted Cu/Nb3Sn composite superconducting wires at room temperature. The object o

42、f this test is to measure the modulus of elasticity and to determine the proof strength of the composite due to yielding of the copper and the copper tin components from the stress versus strain curve. Furthermore, the elastic limit, the tensile strength, and the elongation after fracture can be det

43、ermined by means of the present method, but they are treated as optional quantities because the measured quantities of the elastic limit and the elongation after fracture have been reported to be subject to significant uncertainties according to the international round robin test. The sample covered

44、 by this test procedure should have a bare round or rectangular cross-section with an area between 0,15 mm2and 2,0 mm2and a copper to non-copper volume ratio of 0,2 to 1,5 and should have no insulation. 2 Normative references The following documents, in whole or in part, are normatively referenced i

45、n this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050 (all parts), International Electrotechnical Vocabulary (available at )

46、ISO 376, Metallic materials Calibration of force-proving instruments used for the verification of uniaxial testing machines ISO 6892-1, Metallic materials Tensile testing Part 1: Method of test at room temperature ISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1

47、: Tension/compression testing machines Verification and calibration of the force-measuring system ISO 9513, Metallic materials Calibration of extensometer systems used in uniaxial testing 3 Terms and definitions For the purposes of this document, the definitions given in IEC 60050-815 and ISO 6892-1

48、, as well as the following, apply. BS EN 61788-19:201461788-19 IEC:2013 9 3.1 tensile stress R tensile force divided by the original cross-sectional area at any moment during the test 3.2 strain A displacement increment divided by initial gauge length of extensometers at any moment during the test 3

49、.3 modulus of elasticity E gradient of the straight portion of the stress-strain curve in the elastic deformation region 3.4 extensometer gauge length length of the parallel portion of the test piece used for the measurement of displacement by means of an extensometer 3.5 distance between grips gL length between grips that hold a test specimen in position before the test is started 3.6 0,2 % proof strength Rp0,2stress value where the ductile com