1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 10274:1999 The Euro
2、pean Standard EN 10274:1999 has the status of a British Standard ICS 77.040.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Metallic materials Drop weight tear testThis British Standard, having been prepared under the direction of the Engineering Sector Committee, was publi
3、shed under the authority of the Standards Committee and comes into effect on 15 September 1999 BSI 09-1999 ISBN 0 580 32638 1 BS EN 10274:1999 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard is the English language version of EN 10274:1999. The UK p
4、articipation in its preparation was entrusted by Technical Committee ISE/NFE/4, Mechanical testing of metals, to Subcommittee ISE/NFE/4/2, Ductility tests, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interp
5、retation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards w
6、hich implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does
7、 not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an insid
8、e front cover, the EN title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed throughout this document indicates when the document was last issued.CEN European Committee for Standardization Comite Europe en de Normalisation Europa isches Komitee fu r Normu
9、ng Central Secretariat: rue de Stassart 36, B-1050 Brussels 1999 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 10274:1999 E EUROPEAN STANDARD EN 10274 NORME EUROPE ENNE EUROPA ISCHE NORM May 1999 ICS 77.040.10 English version Met
10、allic materials Drop weight tear test Mate riaux me talliques Essai de chute de masse Metallische Werkstoffe Fallgewichtsversuch This European Standard was approved by CEN on 16 April 1999. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for g
11、iving 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 application to the Central Secretariat or to any CEN member. This European Standard exists in three official ve
12、rsions (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 to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium
13、, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 10274:1999 BSI 09-1999 Foreword This European Standard has been prepared by Technical Committee ECISS/TC 29, Steel
14、tubes and fittings for steel tubes, the Secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by November 1999, and conflicting national standards shall be withdrawn at
15、 the latest by November 1999. This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. This European Standard is considered to be a supporting standard to those application and product standards which in themselves supp
16、ort an essential safety requirement of a New Approach Directive and which make reference to this European Standard. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czec
17、h Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword 2 1 Scope 3 2 Definitions 3 3 Symbols and abbreviations 3 4 Principle 3 5 Apparatus 5 6 Test piece prep
18、aration 5 7 Test procedure 6 8 Test evaluation 6 9 Test report 7 Annex A (informative) Alternative procedure for testing thick material 8 Annex B (informative) Method for calculating the percentage shear area for ferritic materials 8 Annex C (informative) Bibliography 8Page 3 EN 10274:1999 BSI 09-19
19、99 1 Scope This European Standard specifies the drop weight tear test for metallic materials and includes a method for assessing the fracture appearance of ferritic steels. Assessment can also be based on the energy absorbed in fracturing the test piece, particularly for materials other than ferriti
20、c steels. NOTE 1 This test method is based on the use of a falling weight or pendulum, however other types of machine, e.g. with hydraulic actuators, may be used provided that the requirements of this European Standard are satisfied. NOTE 2 The test is most commonly applied to ferritic steel tubes a
21、nd to ferritic steel plate for the manufacture of tubes. 2 Definitions For the purposes of this European Standard, the following definitions apply. 2.1 shear area the area of the fractured surface of the test piece that has broken in a ductile manner NOTE It is normally identified by a grey silk-lik
22、e appearance. 2.2 cleavage area the area of the fractured surface of the test piece that has broken in a brittle manner NOTE It is normally identified by a shiny crystalline appearance. 2.3 anvil that part of the testing machine used to support the test piece during impact 2.4 striker part of the ha
23、mmer which is in contact with the test piece NOTE This definition is identical to that given in EN 10045-2:1992, 3.5. 2.5 hammer the part of the test machine which impacts the test piece 2.6 fracture appearance transition temperature (FATT) the temperature required to cause a specified percentage of
24、 the fracture to occur by shear. Expressed as follows e.g. for 85 % specified percentage of shear fracture at2308C, FATT (85) =2308C. 2.7 ferritic steel steel in which the ferritic state is stable at all service temperatures 3 Symbols and abbreviations 3.1 Symbols and designations a depth of pressed
25、 notch L length of test piece L c minimum length of unflattened central portion of test piece R h radius of curvature of hammer R n root radius of pressed notch R s radius of curvature of anvil support S span between anvils T thickness of test piece W width of test piece u angle of pressed notch 3.2
26、 Abbreviations DWTT drop weight tear test FATT fracture appearance transition temperature (see 2.6) KV Charpy V-notch energy 4 Principle The test is generally carried out on test pieces taken from plate for the manufacture of tubes or from tube with an outside diameter greater than 300 mm and a thic
27、kness greater than 6 mm. The test involves fracturing a test piece containing a pressed notch by supporting it near its ends, and impacting it behind the notch (see Figure 1). The test is carried out at a specified test piece temperature. The test is as follows: a) to measure the relative proportion
28、s of shear and cleavage fracture, which are generally assessed visually, and to derive from these either: 1) the temperature at which a specified percentage of shear fracture has occurred (FATT); or 2) the amount of shear area produced by testing at a specified temperature; and/or b) to measure abso
29、rbed energy at the specified temperature. BSI 09-1999 Page 4 EN 10274:1999 Figure 1 Test piece geometry and recommended flattened tube profilePage 5 EN 10274:1999 BSI 09-1999 5 Apparatus 5.1 The testing machine may be a falling weight type or a pendulum type. Other types of testing machine, e.g. wit
30、h hydraulic actuators, may be used providing it can be demonstrated that their impact velocity and dynamic performance conform to the requirements of 5.2. 5.2 The energy available at impact to be used in the test shall be greater than the anticipated fracture absorption energy of the test piece (see
31、 note). At impact the hammer velocity shall be not less than 5 m/s and not more than 10 m/s. NOTE To ensure regular crack propagation an available energy of 1,5 times the absorbed energy is generally sufficient 1. If the absorbed energy is not measured, the minimum required impact energy (E REQ ) ca
32、n be estimated from the Charpy V-notch energy (KV) adjusted for test piece cross-sectional fracture area using the following expression E REQ = 5.6 (KV) 3 A DWTT A KV where A DWTT is the drop weight tear test fracture area; A KV is the Charpy test fracture area. 5.3 The striking edge of the hammer s
33、hall be radiused and shall be centred on the anvil with the supports at a span of 254 mm as shown in Figure 1. Provision shall be made to prevent out of plane rotation of the test piece on or after impact. The tolerances on the machine and set up dimensions shall be in accordance with Table 1. Table
34、 1 Test machine dimensions and tolerances Measurement Dimension Tolerance mm mm S 254,0 1,5 R s 15,0 1,0 R h 25,0 1,0 Centre line hammer with respect to mid-point between anvil supports 0 1,5 5.4 A temperature controlled environment shall be provided in which the test piece can be soaked in a suitab
35、le medium for temperature conditioning before testing. Provision shall be made for circulation of the medium to ensure a uniform soaking temperature. NOTE A procedure should be developed for test temperatures above or below room temperature to ensure that the temperature variation between the exit f
36、rom the temperature conditioning medium and the execution of the test are within specified limits. 6 Test piece preparation 6.1 Test piece location Test piece location and orientation within the tube or plate shall be as specified in the product standard. 6.2 Test piece 6.2.1 Unless otherwise specif
37、ied in the product standard the test piece may be flattened completely for testing purposes or the central 50 mm may be left with the original pipe curvature. In the latter case the mid thickness at the centre of the test piece shall be in the same plane as the mid thickness at the anvil supports (s
38、ee Figure 1). In the case of dispute the results of tests on test pieces with the central area unflattened shall apply. NOTE Flattening the fracture area of the test piece may give more conservative results than those obtained from an unflattened test piece. 6.2.2 The test piece thickness shall be t
39、he full tube or plate thickness up to and including 19 mm. For thicknesses greater than 19 mm the test piece thickness may be either the full tube or plate thickness or it may be reduced to 19 mm. An alternative procedure for testing thicker materials, reduced in thickness to 19 mm, is given in anne
40、x A. If the test piece thickness is reduced to 19 mm it shall be agreed and documented at the time of enquiry and order. 6.2.3 Test pieces may be prepared from an oversize flame-cut sample, however, final preparation shall be by a cold machining process (e.g. planing, sawing, or milling) to remove a
41、ny heat affected zones. Test piece dimensions and tolerances shall be in accordance with Table 2. Table 2 Test piece dimensions and tolerances Measurement Dimension Tolerance mm mm L 305,0 20,0 W 76,0 1,5 a 5,0 0,5 u 458 28 R n 0,01 to 0,04 Centre line notch with respect to centre line of hammer 0 1
42、,5 L c 50,0 6.2.4 The notch shall be pressed to the depth given in Table 2 with a chisel of minimum hardness 45 HRC, and shall have a radius of 0,02 mm 0,01 mm. Machined notches are prohibited.Page 6 EN 10274:1999 BSI 09-1999 Figure 2 Fracture surface included in percentage shear area determination
43、7 Test procedure 7.1 The test piece shall be soaked in a suitable medium which is at a temperature within the following limits: a) for test temperatures below room temperature: +1,08C and210,08C of the specified test temperature; b) for test temperatures above room temperature: 21,08C and +10,08C of
44、 the specified test temperature. Test pieces shall be separated from each other and from the sides and bottom of the bath by a distance of at least the test piece thickness. When the surface of the test piece has reached the required temperature it shall remain in the medium at that temperature for
45、the greater of the following times (see note). 1) For liquid medium: 15 min or 30 s per mm thickness. 2) For a gaseous medium: 30 min or 1 min per mm thickness. NOTE If evidence can be produced to show that the test piece equilibrium temperature can be developed in a shorter time then these holding
46、times can be reduced. 7.2 The test piece shall be removed from the medium and broken on the test machine, by a single blow. The surface temperature of the test piece at the time of testing shall be within 1,08C of the specified test temperature. This condition is considered to be met if the test is
47、undertaken within 10 s of its removal from the soaking medium which is itself at a temperature within 18Co f the specified test temperature. If the test piece is out of the medium for longer than 10 s, it shall be returned to the bath until the requirements of 7.1 are again fulfilled. 7.3 The test p
48、iece shall be placed in the test machine such that the centre line of the notch is aligned with the centre line of the hammer. The test piece shall be suitably restrained to prevent out of plane rotation on or after impact. 7.4 When appropriate the fracture absorption energy shall be recorded. The e
49、lements of the energy absorption shall be subject to calibration. NOTE It has been found that the most consistent results are obtained when using test machines with anvil support radii of 15 mm 1 mm and hammer radius of 25 mm 1 mm as jamming and friction are minimized under these conditions. 8 Test evaluation 8.1 Ferritic steels 8.1.1 The result of the test is usually expressed as a Fracture Appearance Transition Temperature (FATT), or as a percentage shear value at the specified temperature defined in the product
