1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 11706:2012Carbonaceous materials for the production of aluminium Prebaked anodes Determination of the fracture energyBS ISO 11706:2012 BRITISH STANDARDNational forewordThi
2、s British Standard is the UK implementation of ISO 11706:2012. 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 be obtained on request to its secretary.This publicat
3、ion does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012.ISBN 978 0 580 66497 7 ICS 71.100.10 Compliance with a British Standard cannot confer immunit
4、y from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2012.Amendments issued since publicationDate T e x t a f f e c t e dBS ISO 11706:2012 ISO 2012Carbonaceous materials for the production of aluminium Prebake
5、d anodes Determination of the fracture energyProduits carbons pour la production de laluminium - Anodes prcuites - Dtermination de lnergie de ruptureINTERNATIONAL STANDARDISO11706First edition2012-09-01Reference numberISO 11706:2012(E)BS ISO 11706:2012ISO 11706:2012(E)ii ISO 2012 All rights reserved
6、COPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address be
7、low or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 11706:2012ISO 11706:2012(E)ForewordISO (the International Organization for Stan
8、dardization) is a worldwide 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
9、 to be represented on that committee. 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.International St
10、andards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an In
11、ternational Standard requires approval by at least 75 % of the member bodies casting a vote.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.ISO 11706
12、was prepared by Technical Committee ISO/TC 226, Materials for the production of primary aluminium. ISO 2012 All rights reserved iiiBS ISO 11706:2012BS ISO 11706:2012Carbonaceous materials for the production of aluminium Prebaked anodes Determination of the fracture energy1 ScopeThis International St
13、andard describes a method for the determination of the fracture energy at room temperature. This property is relevant for the thermal shock resistance of prebaked anodes used in the electrolytic cell.2 Normative referencesThe following referenced documents are indispensable for the application of th
14、is document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 8007-2, Carbonaceous materials used in the production of aluminium Sampling plans and sampling from individual units Part 2:
15、 Prebaked anodesISO 12986-1, Carbonaceous materials used in the production of aluminium Prebaked anodes and cathode blocks Part 1: Determination of bending/shear strength by a three-point methodISO 12985-1, Carbonaceous materials used in the production of aluminium Baked anodes and cathode blocks Pa
16、rt 1: Determination of apparent density using a dimensions method3 PrincipleThe amount of energy needed to fracture a notched cylindrical test piece is determined by integrating the force-displacement signals of the testing machine.Notching of the test piece allows to minimize the elastic energy sto
17、red in the specimen and therefore guarantees controlled and smooth crack propagation.The same arrangement and testing equipment as required for the determination of the bending/shear strength by a 3-point method can be used, see ISO 12986-1.A length measurement device for the vertical displacement,
18、a data acquisition system and software able to integrate the force-displacement curve are additionally needed.4 Apparatus4.1 Testing equipmentThe testing machine has a hydraulic system that can be adjusted to control the load increase rate. The maximum achieved load should lie above 1 kN and the pre
19、cision of the load sensor better than 5 N.The 3-point cell complies with ISO 12986-1. The displacement measurement unit shall cover a range of 10 mm with a precision better than 5 m.The arrangement of the cell with the notched sample and the recorded signals are shown in the following figure.INTERNA
20、TIONAL STANDARD ISO 11706:2012(E) ISO 2012 All rights reserved 1BS ISO 11706:2012ISO 11706:2012(E)Key1 pier bar ( 5 to 10 mm)2 support bar ( 5 to 10 mm)3 test piece ( 50 mm, length 130 mm, 60 notched, 2 mm slots)Ls= 100 mmF = force applied to the bottom tableD = displacement sensorFigure 1 3-point t
21、esting set-upThe maximum load reached for typical anodes lies in the range of 500 N to 1000 N while a typical displacement difference between the load increase and the total fracture of the sample is around 0,5 mm and 1 mm. The typical value of the fracture energy of worldwide anodes is around 200 J
22、/m2.5 SamplingThe sampling program and the drilling location of the sample shall be agreed between the seller and buyer in accordance with ISO 8007-2.6 Preparation of the test pieces6.1 Drilling and cuttingCylindrical test pieces with a circular cross-section only shall be used. The test pieces shal
23、l have a diameter of 50 mm +1 mm and a minimum length of 130 mm.Drilling shall be performed with a machine and set-up guaranteeing a uniform diameter throughout the sample length.Cutting is made by using a saw unit providing parallel end-faces of the test piece.6.2 NotchingA 60 angle notched cross-s
24、ectional area shall be prepared. The slot thickness shall be 2 mm.2 ISO 2012 All rights reservedBS ISO 11706:2012ISO 11706:2012(E)A convenient and simple way to prepare the notch is to use a saw having a 2 mm thick blade of 250 mm diameter. The sample positioning is given by fixing the test pieces t
25、o a support fitting in the saw table. After sawing the first slot reaching the precise highest position of the cylinders, the support device with its fixed test piece is turned by 180 for preparing the second slot.6.3 DryingThe test pieces are cleaned and dried overweight at 120 C and cooled to room
26、 temperature.7 Testing procedureThe diameter of the test piece is measured using a caliper according to ISO 12985-1.Set up the piece, with the notch tip aligned to the bottom support bars, on the testing table.Increase the force steadily and smoothly in such a way that the sample breaks totally in a
27、 time period between 5 s and 10 s. Record continuously the load and the displacement of the table.8 Expression of resultsCalculate the fracture energy in J/m2by integrating the force/displacement signals according to the following principle and equations:Figure 2 Integration of the force/displacemen
28、t curveThe zero displacement Xo corresponds to the table position where the first significant sign of load is noticed. The displacement Xf corresponds to the table position where the decreasing load still had a significant positive value.The fracture energy FE can be calculated using the integral fo
29、rmula shown below:FE =12 SFdxXoXfwhere ISO 2012 All rights reserved 3BS ISO 11706:2012ISO 11706:2012(E)F = force in newtonsX = displacement in metresS = broken surface area, equal for an angle of 60 to 0,478 h2(h = sample diameter)Report the result rounded to the unit of J/m2.9 PrecisionThe repeatab
30、ility of this destructive method cannot be tested.The reproducibility of the mean value of a given sample population, with a minimum number of test pieces above 30, is 20 J/m2. (RDC round robin 1997 on anodes.)10 Test reportThe test report shall contain the following information:a) a reference to th
31、is International Standard;b) type, position and orientation of test specimens during the sampling;c) designation of the test piece;d) single fracture energy value of each test piece;e) number of test piece, average and the standard deviation of the population;f) additionally agreed conditions deviat
32、ing from the standard method;g) sampling and test date.4 ISO 2012 All rights reservedBS ISO 11706:2012BS ISO 11706:2012ISO 11706:2012(E) ISO 2012 All rights reservedICS 71.100.10Price based on 4 pagesThis page deliberately left blankBSI is the independent national body responsible for preparing Brit
33、ish Standards and other standards-related publications, information and services. It presents the UK view on standards in Europe and at the international level. BSI is incorporated by Royal Charter. British Standards and other standardisation products are published by BSI Standards Limited.British S
34、tandards Institution (BSI)raising standards worldwideBSI389 Chiswick High Road London W4 4AL UKTel +44 (0)20 8996 9001Fax +44 (0)20 8996 Standards and PASs are periodically updated by amendment or revision. Users of British Standards and PASs should make sure that they possess the latest amendments
35、 or editions.It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using British Standards would inform the Secretary of the technical committee responsible, the identity of which can be found on the
36、 inside frontcover. Similary for PASs, please notify BSI Customer Services.Tel: +44 (0)20 8996 9001 Fax: +44 (0)20 8996 7001BSI offers BSI Subscribing Members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of British Standards and
37、PASs.Tel: +44 (0)20 8996 7669 Fax: +44 (0)20 8996 7001Email: Buying standardsYou may buy PDF and hard copy versions of standards directly using acredit card from the BSI Shop on the website addition all orders for BSI, international and foreign standards publicationscan be addressed to BSI Customer
38、 Services.Tel: +44 (0)20 8996 9001 Fax: +44 (0)20 8996 7001Email: In response to orders for international standards, BSI will supply the British Standard implementation of the relevant international standard, unless otherwise requested.Information on standardsBSI provides a wide range of information
39、 on national, Europeanand international standards through its Knowledge Centre.Tel: +44 (0)20 8996 7004 Fax: +44 (0)20 8996 7005Email: BSI Subscribing Members are kept up to date with standards developments and receive substantial discounts on the purchase priceof standards. For details of these and
40、 other benefits contact Membership Administration. Tel: +44 (0)20 8996 7002 Fax: +44 (0)20 8996 7001 Email: Information regarding online access to British Standards and PASs via British Standards Online can be found at information about British Standards is available on the BSI website at www.bsi-
41、 the data, software and documentation set out in all British Standards and other BSI publications are the property of and copyrighted by BSI, or some person or entity that own copyright in the information used (such as the international standardisation bodies) has formally licensed such information
42、to BSI for commerical publication and use. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission fro
43、m BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. Details and advice can be obtained from the Copyright & Licensing Department.Tel: +44 (0)20 8996 7070Email:
