DIN EN 12814-3-2014 Testing of welded joints of thermoplastics semi-finished products - Part 3 Tensile creep test German version EN 12814-3 2014《热塑性半成品的焊接接头试验 第3部分 拉伸蠕变试验》.pdf

1、July 2014 Translation by DIN-Sprachendienst.English price group 13No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 2

2、5.160.40!%7?“2202891www.din.deDDIN EN 12814-3Testing of welded joints of thermoplastics semi-finished products Part 3: Tensile creep test;English version EN 12814-3:2014,English translation of DIN EN 12814-3:2014-07Prfen von Schweiverbindungen aus thermoplastischen Kunststoffen Teil 3: Zeitstand-Zug

3、versuch;Englische Fassung EN 12814-3:2014,Englische bersetzung von DIN EN 12814-3:2014-07Essais des assemblages souds sur produits semi-finis en thermoplastiques Partie 3: Essai de fluage en traction;Version anglaise EN 12814-3:2014,Traduction anglaise de DIN EN 12814-3:2014-07SupersedesDIN EN 12814

4、-3:2005-10www.beuth.deDocument comprises 27 pagesIn case of doubt, the German-language original shall be considered authoritative.06.14 DIN EN 12814-3:2014-07 2 A comma is used as the decimal marker. National foreword This document (EN 12814-3:2014) has been prepared by Technical Committee CEN/TC 24

5、9 “Plastics” (Secretariat: NBN, Belgium). The responsible German body involved in its preparation was the Normenausschuss Schweien und verwandte Verfahren (Welding and Allied Processes Standards Committee), Working Committee NA 092-00-32 AA Fgen von Kunststoffen. Amendments This standard differs fro

6、m DIN EN 12814-3:2005-10 as follows: a) a NOTE has been added for an alternative test using a whole pipe welded sample (Clause 5) making reference to Annex B (informative) “Whole pipe tensile creep rupture test”; b) a NOTE has been added for the sampling procedures (Clause 6) in case of socket joint

7、s with reference to Annex D (informative) “Testing of socket joints”. Previous editions DIN EN 12814-3: 2000-03, 2005-10 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12814-3 February 2014 ICS 25.160.40 Supersedes EN 12814-3:2000English Version Testing of welded joints in thermoplastics semi-

8、finished products - Part 3: Tensile creep test Essais des assemblages souds sur produits semi-finis en thermoplastiques - Partie 3: Essai de fluage en traction Prfen von Schweiverbindungen aus thermoplastischen Kunststoffen - Teil 3: Zeitstand-Zugversuch This European Standard was approved by CEN on

9、 30 November 2013. CEN 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 m

10、ay be obtained on application to the CEN-CENELEC Management Centre or to any CEN 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 CEN member into its own language and notified

11、 to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Icelan

12、d, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Managem

13、ent Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12814-3:2014 E2 Contents Page Foreword 3 Introduction .4 1 Scope 5 2 Normative references 5 3 Terms and definitions .5 4 Symbols and

14、 designations .5 5 Principle of the test6 6 Sampling procedures 7 7 Dimensions of test specimens .7 8 Cutting and preparation of test specimens 9 9 Mechanical testing 10 10 Test equipment . 10 11 Determination of the long-term welding factor 11 12 Test report . 13 Annex A (informative) Resistance to

15、 slow crack growth . 15 Annex B (informative) Whole pipe tensile creep rupture test 18 Annex C (informative) Minimum creep rupture time of the parent material (ttm) for applicability of the long-term welding factor . 21 Annex D (informative) Testing of socket joints . 22 Bibliography . 25 DIN EN 128

16、14-3:2014-07 EN 12814-3:2014 (E) 3 Foreword This document (EN 12814-3:2014) has been prepared by Technical Committee CEN/TC 249 “Plastics”, the secretariat of which is held by NBN. This European Standard shall be given the status of a national standard, either by publication of an identical text or

17、by endorsement, at the latest by August 2014, and conflicting national standards shall be withdrawn at the latest by August 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for

18、 identifying any or all such patent rights. This document supersedes EN 12814-3:2000. The main changes with respect to the previous edition are listed below: a) addition of a NOTE for an alternative test using a whole pipe welded sample (Clause 5) making reference to Annex B (informative), Whole pip

19、e tensile creep rupture test; b) addition of a NOTE for the sampling procedures (Clause 6) in case of socket joints with reference to Annex D (informative), Testing of socket joints. EN 12814, Testing of welded joints of thermoplastics semi-finished products, is divided into the following parts: Par

20、t 1: Bend test; Part 2: Tensile test; Part 3: Tensile creep test (the present document); Part 4: Peel test; Part 5: Macroscopic examination; Part 6: Low temperature tensile test; Part 7: Tensile test with waisted test specimens; Part 8: Requirements. According to the CEN-CENELEC Internal Regulations

21、, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, L

22、atvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 4 Introduction The design of welded thermoplastics constructions under static load is based o

23、n the long-term creep rupture with behaviour, specifically the resistance to slow crack growth of the thermoplastics material and the welds. For design purposes, the relevant characteristic values for the welded joints are the “long-term tensile welding factors” to which this European Standard provi

24、des the test method. The long-term tensile welding factors are normally used in conjunction with the creep rupture curve of the parent material, given for example in EN 1778, when designing welded semi-finished products under static load. The long-term tensile welding factor(s), the crack behaviour

25、and the appearance of the fracture surface provide information on the quality of the weld. NOTE The behaviour of the failure obtained during the tensile creep test can be related to the notch sensitivity of the parent material. An example of a test to provide information about the notch sensitivity

26、of parent material is given in Annex A. DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 5 1 Scope This European Standard specifies the dimensions, the method of sampling and the preparation of the test specimens, and the conditions for performing the tensile creep test perpendicular to the weld in order

27、to determine the long-term tensile welding factor. A tensile creep test may be used in conjunction with other tests (e.g. bend test, tensile test, macrographic examination, ) to assess the performance of welded assemblies, made from thermoplastics materials. The test is applicable to welded assembli

28、es made from thermoplastics materials filled or unfilled such as tubes and fittings, sheets, plates and profiles, but not reinforced, irrespective of the welding process used. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are ind

29、ispensable 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. EN 13100-1, Non destructive testing of welded joints of thermoplastics semi-finished products Part 1: Visual

30、 examination EN ISO 899-1, Plastics Determination of creep behaviour Part 1: Tensile creep (ISO 899-1) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 test temperature temperature of the medium surrounding the test specimen during the test 3.

31、2 test stress test load divided by the minimum cross sectional area of the test specimen 3.3 creep rupture curve regression curve through the geometric mean values of failure times 3.4 minimum failure time ttmcreep rupture time of the parent material to ensure that the test method is applicable 3.5

32、ductile fracture large scale deformation of material from fracture surfaces 3.6 brittle fracture little or no deformation of material from fracture surfaces 4 Symbols and designations Symbols and designations are given in Table 1. DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 6 Table 1 Symbols and desi

33、gnations Symbols Designations Units a Minimum measured thickness of test specimen within calibrated and parallel length mm anNominal thickness of test piece mm b Width of calibrated and parallel length of the test specimen mm b1Width of shoulder of the test specimen mm c Depth of the notch mm DnNomi

34、nal outside diameter of the tube mm flLong-term tensile welding factor FsValue of the force applied to the welded test specimen calculated from the chosen value of sN Ft Value of the force applied to the unwelded test specimen calculated from the chosen value of t N L Total length of the test specim

35、en mm LjMinimum distance between the clamping jaws mm L0Calibrated and parallel length of the test specimen mm LwaMaximum width of the weld bead of the test specimen mm r Radius of shoulder of the test specimen mm ttm Minimum failure time h s Value of stress of the welded test specimens used in the

36、calculation of fl N/mm2t Reference stress. Value of stress of the unwelded test specimens, used in the calculation of fl N/mm2aFor extrusion and hot gas welds only. 5 Principle of the test The test involves subjecting a test specimen to a constant load until fracture occurs. The time to fracture is

37、measured and recorded. NOTE An alternative test using a whole pipe welded sample rather that a test specimen cut form the weld is given in Annex B. DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 7 The tests are carried out over a range of temperatures and loads, and in a test medium. Only such media sha

38、ll be used which cause no swelling or degradation of the polymer. Examples of available test media are air, water or solutions of demineralised water with detergents. Care should be taken to ensure that the condition of the test medium does not influence the results of the test. The applicability of

39、 the long-term tensile welding factor for design purposes requires a minimum creep rupture time for the parent material (ttm). Before determining the long-term welding factor for the materials mentioned in Annex C, a tensile creep test should be carried out on the parent material at one of the test

40、conditions given in Table C.1. The values of creep rupture time should be at least that quoted in Table C.1. Application standards may prescribe higher values for these rupture times depending upon the semi-finished product and material. 6 Sampling procedures Welded and unwelded test specimens shall

41、 be taken from the same test piece. NOTE In the case of socket joints, see Annex D. The test specimens (welded and unwelded) shall be cut perpendicular to the welded joint at least eight hours after welding. For sheets where the extrusion direction is different on either side of the weld, the unweld

42、ed test specimens shall be taken from the side of the test piece which has the lowest creep rupture time. Each test specimen shall be marked in order to identify its original position within the test piece. No heat treatment or mechanical straightening operations shall be carried out on the test spe

43、cimen. 7 Dimensions of test specimens The dimensions of test specimens according to Figure 1 are given in Table 2 and those according to Figure 2 are given in Table 3. Profiles can be tested if test specimens are in accordance with the dimensions given in Table 2 or Table 3. For tubes having nominal

44、 outside diameter less than 20 mm, the whole tube shall be tested. In this case, the minimum distance between the clamps shall be 200 mm. DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 8 Key Lj= L0+ (2xb) Figure 1 Type 1 test specimen for flat and tubular assemblies Figure 2 Type 2 test specimen for fla

45、t and tubular assemblies DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 9 Table 2 Dimensions of type 1 test specimens Dimensions in millimetres Dnor anb L0L 20 Dn20 1,5 x an3 x an+ Lw with 120 min L0+ 80 Table 3 Dimensions of type 2 test specimens Dimensions in millimetres Dnor anb min. b1L0L r 20 Dn20

46、1,5 x an2,5 x an3 x an+ Lwwith 120 min L0+ 80 60 Where the beads are left intact in service, they shall be left intact for the test. Where the beads are removed in service, they shall be removed prior to testing. The minimum value for b shall be 6 mm. The tolerance for b shall be 1 mm. The tolerance

47、 for L0shall be 2 mm. The variation of b over the length L0shall not exceed 2 % of the average value of b. 8 Cutting and preparation of test specimens The tensile creep test specimens shall be cut with parallel sides as shown in Figures 1 and 2. During cutting, heating of the test specimen shall be

48、minimized. The cutting operation shall not cause any damage to the test specimen. After cutting, a visual examination of the weld according to EN 13100-1 shall be carried out and recorded. DIN EN 12814-3:2014-07 EN 12814-3:2014 (E) 10 9 Mechanical testing The stress is applied to the test specimen at constant temperature, static tensile load and constant ambient conditions. Test specimens shall be conditioned to the test temperature before loading. The variation of the test temperature shall not exc