1、BSI Standards PublicationBS ISO 12986-1:2014Carbonaceous materials used inthe production of aluminium Prebaked anodes and cathodeblocksPart 1: Determination of bending/shearstrength by the three-point methodBS ISO 12986-1:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implemen
2、tation of ISO 12986-1:2014.It supersedes BS 6043-3.5.1:2000 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/24, Raw materials for the aluminium industry.A list of organizations represented on this committee can beobtained on request to its secretary
3、.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 81219 4ICS 71.100.10Compliance with a British Standard cannot confer
4、 immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 July 2014.Amendments issued since publicationDate Text affectedBS ISO 12986-1:2014 ISO 2014Carbonaceous materials used in the production of aluminium Prebaked a
5、nodes and cathode blocks Part 1: Determination of bending/shear strength by the three-point methodProduits carbons utiliss pour la production de laluminium Anodes prcuites et blocs cathodiques Partie 1: Dtermination de la rsistance la flexion par la mthode trois pointsINTERNATIONAL STANDARDISO12986-
6、1Second edition2014-06-15Reference numberISO 12986-1:2014(E)BS ISO 12986-1:2014ISO 12986-1:2014(E)ii ISO 2014 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by
7、 any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211
8、Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 12986-1:2014ISO 12986-1:2014(E) ISO 2014 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Apparatus . 26
9、 Test specimen 36.1 Sampling and sample preparation . 36.2 Size and geometry 47 Procedure. 48 Calculation and expression of results . 49 Precision . 510 Test report . 5Bibliography 6BS ISO 12986-1:2014ISO 12986-1:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide
10、federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that c
11、ommittee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document
12、 and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives,
13、Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development o
14、f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific
15、 terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 226, Materials for the
16、production of primary aluminium.This second edition cancels and replaces the first edition (ISO 12986-1:2000), which has been technically revised.ISO 12986 consists of the following parts, under the general title Carbonaceous materials used in the production of aluminium Prebaked anodes and cathode
17、bocks: Part 1: Determination of bending strength by the three-point method Part 2: Determination of bending strength by the four-point methodiv ISO 2014 All rights reservedBS ISO 12986-1:2014INTERNATIONAL STANDARD ISO 12986-1:2014(E)Carbonaceous materials used in the production of aluminium Prebaked
18、 anodes and cathode blocks Part 1: Determination of bending/shear strength by the three-point method1 ScopeThis part of ISO 12986 specifies a three-point method to determine the flexural strength of carbon and solid graphite materials at room temperature.NOTE ISO 12986 is based on DIN 51902.2 Normat
19、ive referencesThe 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 edition of the referenced document (including any amendments) ap
20、plies.ISO 4288, Geometrical Product Specifications (GPS) Surface texture: Profile method Rules and procedures for the assessment of surface textureISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration
21、 of the force-measuring systemISO 8007-1, Carbonaceous materials used in the production of aluminium Sampling plans and sampling from individual units Part 1: Cathode blocksISO 8007-2, Carbonaceous materials used in the production of aluminium Sampling plans and sampling from individual units Part 2
22、: Prebaked anodesISO 8007-3, Carbonaceous materials used in the production of aluminium Sampling plans and sampling from individual units Part 3: Sidewall blocks3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1flexural strengthbmaximum flexural s
23、tress developed in a specimen during a flexural test to ruptureNote 1 to entry: The flexural strength is calculated as the quotient of the bending moment at maximum force, before or at rupture of the specimen under the conditions of the three-point method and its section modulus.bb=MZwhere ISO 2014
24、All rights reserved 1BS ISO 12986-1:2014ISO 12986-1:2014(E)Mbis the bending moment at maximum force, in Newton millimetres;Z is the section modulus, in cubic millimetres.Note 2 to entry: The flexural strength is expressed in megapascals (MPa).Note 3 to entry: Generally, the maximum force displayed o
25、n the test machine and the force at fracture are similar; if they are different, the term refers to the maximum force displayed.3.2bending momentMbcomponent of moment of force perpendicular to the longitudinal axis of a beam or a shaftNote 1 to entry: Mbis the maximum moment at fracture, calculated
26、from the maximum force displayed by the testing machine and the geometry of the test specimen. Generally, the maximum force displayed on the test machine and the force at fracture are similar; if they are different, the term refers to the maximum force displayed.3.3section modulusZratio of the secon
27、d axial moment of area to the maximum radial distance of any point in the surface considered from the Q-axis with respect to which the second axial moment of area is definedNote 1 to entry: The section modulus can be expressed mathematically as shown in the following formula.Z = Ia/rQ,maxwhereIais t
28、he second axial moment of area;rQ,maxis the maximum radial distance considered from the Q-axis with respect to which Iais defined.Note 2 to entry: The section modulus is calculated for the most common cross sections in Figure 2.4 PrincipleA bar-shaped test specimen is placed on two bearing blocks an
29、d a force is applied to its centre until the test specimen ruptures; the force is equally distributed on two points. The flexural strength is calculated from the maximum force, the distance between the supports, and the dimensions of the cross-section of the test specimen.5 Apparatus5.1 Compression-
30、testing machine, which meets at least the demands of class 2 in accordance with ISO 7500-1.5.2 Measuring device, with two bearing blocks and one force edge.The device shall ensure a cardanic suspension and movable support blocks; see Figure 1. The radius of curvature of the bearing blocks and of the
31、 force edges shall be in the range 2 mm to 5 mm. The distance between the points of support should be variable in order to adjust the measuring device to different sample geometries.2 ISO 2014 All rights reservedBS ISO 12986-1:2014ISO 12986-1:2014(E)5.3 Measuring device, (e.g. vernier calliper in ac
32、cordance with ISO 13385-1) capable of measuring the linear dimensions of the test specimens with an accuracy of 0,5.5.4 Measuring device, capable of measuring the surface roughness (peak-to-valley height) of test specimens.DKey1 force edge2 test specimen3 supportl length of test specimenD diameter o
33、f test specimenlsdistance between supportsr1, r2radii of supportsFigure 1 Three-point test setup6 Test specimen6.1 Sampling and sample preparationSampling shall be in accordance with the appropriate method i.e. ISO 8007-1, ISO 8007-2, ISO 8007-3, or be agreed with the applicant. The number of specim
34、ens shall be defined with respect to the homogeneity of the material to be tested. ISO 2014 All rights reserved 3BS ISO 12986-1:2014ISO 12986-1:2014(E)The side faces of the specimens shall be machined such that the surface roughness in terms of the peak-to-valley height Ra, when measured in accordan
35、ce with ISO 4288, is smaller than 15 m. Depressions that can clearly be regarded as surface pores are not considered.6.2 Size and geometryCylindrical or prismatic specimens can be used, provided that the smallest dimension be at least twice the diameter of the largest structural constituent (e.g. ma
36、ximum particle size) of the material to be tested, but not smaller than 4 mm. The length of the specimens shall be at least 3,5 times their width or diameter.7 Procedure7.1 Perform all measurements at room temperature, i.e. in the range 10 C to 35 C.7.2 Choose the measuring range of the testing mach
37、ine such that the expected load at failure is at least 1/10 of full scale. Centre the test specimen on the support, with the longitudinal axis perpendicular to the support edges. The width between supports shall be at least three times the width or diameter of the specimen. The distance between the
38、force edges shall be equal to the width or diameter of the test specimen.In the case of prismatic specimens, ensure that the specimens rest entirely on the support edges, that at least one loading edge is movable and that the loading edges transmit the force uniformly over the whole width to the tes
39、t specimens. In the case of cylindrical specimens, it is recommended that support edges be used with a diameter about 2 mm larger than the diameter of the test specimens to prevent the specimens from rolling away.Increase the force uniformly and shock-free at a rate (velocity of the force edge) of a
40、bout 5 mm/min or about 0,5 N/mm2/s until the test specimen fractures. Determine the maximum force.8 Calculation and expression of resultsCalculate the flexural strength, SB, in megapascals, from Formula (1).SFBst=lM4106(1)whereF is the force, in N at fracture;lsis the distance, in mm between the sup
41、ports;Mtis the moment of resistance of the test specimen, in mm3.Mtis calculated from Formula (2).MDt=pi332(2)whereD is the diameter of the test specimen, expressed in mm.4 ISO 2014 All rights reservedBS ISO 12986-1:2014ISO 12986-1:2014(E)a) Square b) Rectangle c) Circle d) RingZh=36Zbh=26ZD=pi332ZD
42、dD=pi3244()KeyZ section moment, in mm3h height of a rectangular cross-section, in mmb breadth of a rectangular cross-section, in mmD external diameter of a circular cross-section, in mmd internal diameter of a ring cross-section, in mmFigure 2 Calculation of section moments for cross-sections of the
43、 most common geometries9 PrecisionMean values measured to this method made under repeatable test conditions for test specimens with the recommended dimensions shall differ by no more than 5 % absolute for a statistical confidence level of 95 %.10 Test reportThe test report shall contain the followin
44、g information.a) a reference to this part of ISO 12986;b) type, position, and orientation of test specimens during the sampling procedure;c) designation of the test specimens;d) number of test specimens;e) linear dimensions of test specimens, in mm;f) flexural strength, b, in MPa, rounded to the nea
45、rest 0,1 MPa, individual values and mean value;g) additionally agreed conditions deviating from this part of ISO 12986;h) test date. ISO 2014 All rights reserved 5BS ISO 12986-1:2014ISO 12986-1:2014(E)Bibliography1 ISO 13385-1, Geometrical product specifications (GPS) Dimensional measuring equipment
46、 Part 1: Callipers; Design and metrological characteristics2 DIN 51902, Testing of carbonaceous materials Determination of flexural strength by three point method Solid materials6 ISO 2014 All rights reservedBS ISO 12986-1:2014BS ISO 12986-1:2014ISO 12986-1:2014(E) ISO 2014 All rights reservedICS 71
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