1、 STDDBSI BS EN 10274-ENGL 1999 = 1b2Ybb9 0798019 972 BRITISH STANDARD Metallic materials - Drop weight tear test The European Standard EN 102741999 has the status of a British Standard ICs 77.040.10 BS EN 102 74: 1999 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW - BS EN 102
2、741999 direction of the Engineering Amd. No. Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 September 1999 National foreword Date Comments This British Standard is the English language version of EN 102741999. The UK participation in its pr
3、eparation was enirusted by Technical Committee ISE/NFE/4, Mechanical testing of metals, to Subcommittee ISE/Nl?E/4L?, Ductility tests, which has the responsibility to: - aid enquirers to understand the text; - present to the responsible European committee any enquiries on the - monitor related inter
4、national and European developments and promulgate interpretation, or proposals for change, and keep the UK interests informed them in the LJK A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement i
5、ntemational or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “Intedonal Standards Correspondence Index“, or by using the “Find“ facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to inclu
6、de 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 inside front cover, the EN
7、title page, pages 2 to 8, an inside back cover and a back cover. The BSI copyright notice displayed throughout this document in or 2) the amount of shear area produced by teshg at a specified temperature; andor b) to measure absorbed energy at the specified temperature. O BSI 09-1999 Page 4 EN 10274
8、1999 I/ I i I M :I .-. I I i I J- 1 O BSI 09-1999 A 1 v - 5 Apparatus 6.1 The testing machine may be a falling weight type or a pendulum type. other types of testing machine, e.g. with hydraulic actuators, may be used providing it can be demonstrated that their impact velocity and dynamic performanc
9、e conform to the requirements of 6.2. 6.2 The energy adable at impact to be used in the test shail be greater than the anticipated fracture absorption energy of the test piece (see note). At impact the hammer velocity shall be not less than 5 m/s and not more than 10 ds. NOTE To ensure regular crack
10、 propagation an available energy of 1,5 times the absorbed energy is generally sufficient i. If the absorbed energy is not measured, the minimum required impact energy (EREQ) can be estimated from the Charpy V-notch energy (KV) austed for test piece cross-sectional fracture area using the foliowing
11、expression Measurement where AD, A, is the drop weight tear test fracture area; is the Charpy test fracture area Dimension mm 6.3 The striking edge of the hammer shall be radiused and shall be centred on the anvii with the supports at a span of 254 mm as shown in Figure 1. Provision shall be made to
12、 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 “hble 1. Measurement Table 1 - Test machine dimensions and Dimension mm S R, Centre line hammer with respect to mid-point between anvil supports Rh 254
13、,o 15,O 25,O O f1,5 f1,o f1,O 6.4 A temperature controlled environment shall be provided in which the test piece cm be soaked in a suitable medium for temperature conditioning before testing. Provision shall be made for circulation of the medium to ensure a uniform soalng temperature. NOTE A procedu
14、re should be developed for test temperatures above or below room temperature to ensure that the temperature vanation between the exit from the temperature conditioning medium and the execution of the test are within specified limits. Page 6 EN 102741999 6 %st piece preparation 6.1 Test piece locatio
15、n Test piece location and orientation wilhin the tube or plate shall be as specified in the product standard. 6.2 Test piece 6.2.1 Unless otherwise specified in the product standard the test piece may be flattened completely for testing purposes or the cenimi 50 mm may be left with the ongmal pipe c
16、urvature. in the latter case the mid thichess at the centre of the test piece shall be in the same plane as the mid thickness at the anvil supports (see Figure 1). In the case of dispute the results of tesis on test pieces with the central asea unflattened shall apply. NOTE Flattening the fracture a
17、rea of the test piece may give more conservative results than those obtained from an unflattened test piece. 6.2.2 The test piece thickness shail be the full tube or plate thickness up to and hcluduig 19 mm. For thicknesses greater than 19 mm the test piece thickness may be either the fuli tube or p
18、late thickness or it may be reduced to 19 mm. An alternative procedure for testing thicker materiais, reduced in thickness to 19 mm, is given in annex k If the test piece thickness is reduced to 19 nun it shall be agreed and documented at the time of enquiry and order. 6.2.3 Test pieces may be prepa
19、red lkom an oversize fame-cut sample, however, final preparation sha be by a cold machining process (e.g. planing, sawing, or milling) to remove any heat affected zones. Test piece dimensions and tolerances shall be in accordance with Pable 2. Table 2 - Test piece dimensions and L W U 305,O 76,O 570
20、 I 0,Ol to 0,04 Centre lie notch with respect to centre line of hammer Tolerance mm 90,o f1,5 fo,5 %? - f1,5 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,Ol mm. Machined notches are prohibited BSI 09-199
21、9 STD-BSI BS EN 10274-ENGL 1999 1b24bbS 079802b O02 W Page 6 EN 102741999 7 %st 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: +1,0 “C and - 10,O “C of the specified test temper
22、ature; b) for test temperatures above room temperature: - 1,0 “C and + 10,O “C of the specified test temperature. Test pieces shail 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 reache
23、d the required temperature it shall remain in the medium at that temperature for the greater of the following times (see note). 1) For liquid medium: 15 min or 30 s per mm thiChecS. 2) For a gaseous medium: 30 min or 1 min per mm thickness. NOTE If evidence can be produced to show that the test piec
24、e equilibrium temperature can be developed in a shorter time then these holding 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 shail be within k1,O “C of the
25、specified test temperature. This condition is considered to be met if the test is undertaken within 10 s of its removal from the soaking medium which is itself at a temperature withjn fl “C of the specified test temperature. If the test piece is out of the medium for longer than 10 s, it shall be re
26、turned to the bath untii the requirements of 7.1 are again med. 7.3 The test piece shall be placed in the test machine such that the centre line of the notch is aligned with the cenixe line of the hammer. The test piece shall be suitably restrained to prevent out of plane rotation on or after impact
27、 7.4 When appropriate the fracture absorption energy shall be recorded. The elements of the energy absorption shail be subject to calibmtion. NOTE It has been found that the most consistent results are obtained when using test machines with anvil siipport radii of 15 mm * 1 mm and hammer radius of 2
28、6 mm * 1 mm as jamniing and friction are minimized under these conditions. 8 Test evalmtion 8.1 Ferritic steels 8.1.1 The result of the test is usually expressed as a Fracture Appearance ii-ansition Temperature PATT), or as a percentage shear value at the specified temperature defined in the product
29、 standard 8.1.2 For test piece thicknesses of 19 mm or less, the percentage shear area of the fracture surface shall be evaluated, neglecting the fracture surface for a distance of one test piece thickness (u from the root of the notch and for a distance of one test piece thickness from the side opp
30、osite the notch. For test piece thicknesses greater than 19 nun, the neglected regions shall be 19 nun. The shaded area in Figure 2 ilustsates that portion of the fracture surface to be considered in the evaluation of the percentage shear area Methods for calculating the percentage shear area for fe
31、rritic steels are given in annex B. Excessive plastic deformation at the impact point may occur in very tough materials over 19 mm thick which leads to conservative results. An alternative method for assessing the FATI of ferritic steels having thicknesses greater than 19 mm is given in annex A whic
32、h can also be used when the impact energy of the test machine is limited Notch This area to be evaluated in the determination of the percentage shear of the fracture surface Figure 2 - Fracture surface included in percentage shear area determination O BSI 09-1999 STD-BSI BS EN 10279-ENGL 1999 Lb24bb
33、9 0798027 Ti.19 Page 7 EN 102741999 8.1.3 The fracture sha be assessed when viewed perpendicularly to the surface. If a fracture surface exhibits areas having an arrowhead form, these areas shall be classed as cleavage (see Figure 3). Occasionally test pieces exhibiting the fracture appearance shown
34、 in Figure 4 will be encountered. These fractures have intermittent regions of shear and cleavage fracture. The individual areas of cleavage fracture shall be summed. Cleavage in separations not included in shear area rating are shown in Figure 5. NOTE Shear areas may contain areas of apparent separ
35、ation which can be ignored. 8.2 Other materials The result of the test is generally expressed as the fracture absorption energy I II I l I C denotes the cleavage regions Figure 3 - Appearance of arrowhead cleavage fracture C denotes the cleavage regions Figure 4 - Alternate shear-cleavage fracture a
36、ppearance 1 Figure 6 - Cleavage in separations not included in shear area rating 9 %st report The test report shall include at least the following OrmatiO a) reference to this European Standard i.e. EN 10274; b) identification of the test piece; e.g. cast No./ tube Nohdentjfication No.; c) materid s
37、pecification if known; d) dimensions of the plate or tube; e) test piece thickness; f) impact energy used in the height of drop of the hammer, g) whether the test piece has been flattened, h) the percentage shear area and test temperature of each test piece when appropriate; i) the fracture appearan
38、ce transition temperature corresponding to a specified percentage shear area when appropriate; j) fracture absorption energy when appropriate. or the mass and O BSI 09-1999 STDmBSI BS EN L027Y-ENGL L999 E Lb2Ybb9 0798028 985 E Plate or tube wall thickness mm Page 8 EN 102741999 Temperature reduction
39、 “C Annex A (informative) Alternative procedure for testing thick material When this procedure is adopted, it is necessasy for test pieces with thicknesses greater than 19 mm to be reduced in thickness to 19 mm minimum by machining one or both surfaces. They should be tested and assessed as describe
40、d in clauses 7 and 8. For ferritic steels 540 mm thick the test temperature should be reduced by the amount given in Table A. 1. NOTE For ferritic materials greater than 40 mm thick and for other materiais the procedure to be used should be agreed between the purchaser and manufacturer at the time o
41、f enquiry and order. B.2 For shear areas between 45 % and 100 % of the fracture surface on test piece thicknesses of 19 mm or less the percentage shear area may be calculated from the formula: (W- U - 2) T-(3/4)AB X 100 (W- a - 2x)T % shear area = where A B T W a z is the width of the cleavage fract
42、ure at the “one I“ line beneath the notch (mm); is the length of the cleavage fracture in between the “one T lines (mm); is the test piece thickness (mm); is the width of the test piece (mm); is the depth of the pressed notch (mm); is the test piece thickness 519 mm (x = 19 for thicknesses 19 mm). 1
43、9 122 22 129 575 1 11,O Annex B (informative) Method for calculating the percentage shear area for ferritic materials B.l The percentage shear area of the fracture surface should be determined by one of the following methods. - Measure the shear area of the fracture with a pianimeter on photograph o
44、r opticai projection of the fracture surface. - Compare the fracture surface with a set of reference specimens. The percent shear area of the reference specimens should have been evaiuated with a planimeter; the thickness of the reference specimen should be identical to that of the evaluated specime
45、n S mm. - Follow the procedure described in B.2. - Use any other procedure that can be shown to produce results equivalent to those obtained from one of the three methods above. Annex C (informative) Bibliography i Fallgewichtversuch nach Battelle, Stahl-Eisen-Prufblatt 1326 1983. O BSI 09-1999 STD.
46、BS1 BS EN 102711-ENGL 1999 E Lb211bb 0798029 &LI BS EN 102741999 BSI 389 Chiswick High Road London w4 4AL BSI - British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international leve
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