BS EN ISO 06506-2-2014

BSI Standards Publication BS EN ISO 6506-2:2014 Metallic materials — Brinell hardness test Part 2: Verification and calibration of testing machinesBS EN ISO 6506-2:2014 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN ISO 6506-2:2014. It supersedes BS EN ISO 6506-2:2005 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee ISE/101/5, Indentation hardness testing. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. © The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 79050 8 ICS 77.040.10 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2014. Amendments/corrigenda issued since publication Date T e x t a f f e c t e d EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 6506-2 September 2014 ICS 77.040.10 Supersedes EN ISO 6506-2:2005 English Version Metallic materials - Brinell hardness test - Part 2: Verification and calibration of testing machines (ISO 6506-2:2014) Matériaux métalliques - Essai de dureté Brinell - Partie 2: Vérification et étalonnage des machines d essai (ISO 6506- 2:2014) Metallische Werkstoffe - Härteprüfung nach Brinell - Teil 2: Überprüfung und Kalibrierung der Prüfmaschinen (ISO 6506-2:2014) This European Standard was approved by CEN on 30 August 2014. 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 may 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 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, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG CEN-CENELEC Management 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 ISO 6506-2:2014 EBS EN ISO 6506-2:2014 EN ISO 6506-2:2014 (E) 3 Foreword This document (EN ISO 6506-2:2014) has been prepared by Technical Committee ISO/TC 164 “Mechanical testing of metals” in collaboration with Technical Committee ECISS/TC 101 “Test methods for steel (other than chemical analysis)” the secretariat of which is held by AFNOR. 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 March 2015, and conflicting national standards shall be withdrawn at the latest by March 2015. 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 identifying any or all such patent rights. This document supersedes EN ISO 6506-2:2005. According to the CEN-CENELEC Internal Regulations, 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, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 6506-2:2014 has been approved by CEN as EN ISO 6506-2:2014 without any modification. BS EN ISO 6506-2:2014ISO 6506-2:2014(E)© ISO 2014 – All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references 1 3 General conditions . 1 4 Direct verification . 2 4.1 General . 2 4.2 Measurement of the test forces 2 4.3 Measurement of the properties of the indenter ball 2 4.4 Calibration of the indentation diameter measuring system 3 4.5 Verification of the testing cycle . 4 5 Indirect verification 4 6 Intervals between verifications 5 7 Verification report/calibration certificate 6 Annex A (informative) Uncertainty of measurement of the verification results of the hardness testing machine 7 Annex B (normative) Verification of hardness testing machines that are incapable of meeting the specified force/time profile .14 Bibliography .15BS EN ISO 6506-2:2014ISO 6506-2:2014(E) Foreword ISO (the International Organization for Standardization) 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 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. The procedures used to develop this document 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, 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 of 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 terms and expressions related to conformity assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 164, Mechanical testing of metals, Subcommittee SC 3, Hardness testing. This third edition cancels and replaces the second edition (ISO 6506-2:2005), which has been technically revised. ISO 6506 consists of the following parts, under the general title Metallic materials — Brinell hardness test: — Part 1: Test method — Part 2: Verification and calibration of testing machines — Part 3: Calibration of reference blocks — Part 4: Table of hardness valuesiv © ISO 2014 – All rights reservedBS EN ISO 6506-2:2014INTERNATIONAL ST ANDARD ISO 6506-2:2014(E) Metallic materials — Brinell hardness test — Part 2: Verification and calibration of testing machines 1 Scope This part of ISO 6506 specifies methods of direct and indirect verification of testing machines used for determining Brinell hardness in accordance with ISO 6506-1, and also specifies when these two types of verification has to be performed. The direct verification involves checking that individual machine performance parameters fall within specified limits whereas the indirect verification utilizes hardness measurements of reference blocks, calibrated in accordance with ISO 6506-3, to check the machine’s overall performance. If a testing machine is also to be used for other methods of hardness testing, it has to be verified independently for each method. This part of ISO 6506 is applicable to both fixed location and portable hardness testing machines. For machines that are incapable of satisfying the specified force-time profile, the direct verification of force and testing cycle can be modified by the use of Annex B. 2 Normative references The 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) applies. ISO 376, Metallic materials — Calibration of force-proving instruments used for the verification of uniaxial testing machines ISO 6506-1:2014, Metallic materials — Brinell hardness test — Part 1: Test method ISO 6506-3, Metallic materials — Brinell hardness test — Part 3: Calibration of reference blocks ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method 3 General conditions Before a Brinell hardness testing machine is verified, the machine shall be checked to ensure that it is properly set up in accordance with the manufacturer’s instructions. Especially, it should be checked that a) the mount holding the ball-holder slides correctly in its guide, b) every ball-holder with a ball used during the calibration is firmly held in the mount, c) the test force is applied and removed without shock, vibration, or overrun and in such a manner that the readings are not influenced, and d) if the indentation diameter measuring system is integrated into the machine, — the change from removing the test force to measuring mode does not influence the diameter measurements, © ISO 2014 – All rights reserved 1BS EN ISO 6506-2:2014ISO 6506-2:2014(E) — the illumination does not affect the diameter measurements, and — the centre of the indentation is in the centre of the field of view, if necessary. 4 Direct verification 4.1 General 4.1.1 Direct verification should be carried out at a temperature of (23 ± 5) °C. If the verification is made outside this temperature range, this shall be reported in the verification report. 4.1.2 The instruments used for verification shall be traceable to the SI. 4.1.3 Direct verification involves a) measurement of the test forces, b) measurement of the diameter, hardness, and density of the indenter ball, c) calibration of the indentation diameter measuring system, and d) measurement of the testing cycle. For each of the above items, direct verification also includes assessment of the results against the specified tolerances. 4.2 Measurement of the test forces 4.2.1 Each test force shall be measured within the working range of the testing machine. When the force is applied in open-loop mode by a lever or other system employing a mechanical advantage, this shall be done at no fewer than three positions of the indenter uniformly spaced throughout its range of movement during testing. 4.2.2 Three measurements shall be made for each force at each position of the indenter. Immediately before each measurement is taken, the indenter shall be moved in the same direction as during testing. 4.2.3 The force shall be measured by one of the following two methods: — by means of a force-proving instrument in accordance with ISO 376 Class 1 or better; — by balancing against a force, accurate to ±0,2 %, applied by means of calibrated masses or another method with the same accuracy. 4.2.4 Each measurement of a force shall be within ±1,0 % of the nominal test force (see Formula A.2), as defined in ISO 6506-1. 4.3 Measurement of the properties of the indenter ball 4.3.1 The indenter consists of a ball and an indenter holder. The verification applies only to the ball. 4.3.2 For the purpose of verifying the size and the hardness of the balls, a minimum of two balls, selected at random from a batch, shall be tested. Each sampled ball shall be verified for size and hardness and then discarded. 4.3.3 The balls shall be polished and free from surface defects.2 © ISO 2014 – All rights reservedBS EN ISO 6506-2:2014ISO 6506-2:2014(E) 4.3.4 The user shall either measure the balls to ensure that they meet the following requirements or shall obtain balls from a supplier certifying that the following conditions are met. 4.3.4.1 The diameter shall be determined by taking the mean value of not less than three single values of diameter measured at different positions on the ball. No single value shall differ from the nominal diameter by more than the tolerance given in Table 1. Table 1 — Tolerances for the different ball diameters Ball diameter mm Tolerance mm 10 5 2,5 1 ±0,005 ±0,004 ±0,003 ±0,003 4.3.4.2 The characteristics of the tungsten carbide composite balls shall be as follows: a) Hardness: The hardness shall be not less than 1 500 HV, when determined in accordance with ISO 6507-1. The tungsten carbide composite ball can be tested directly on its spherical surface or by sectioning the ball and testing on the ball interior. b) Density: ρ = (14,8 ± 0,2) g/cm 3 . The density can be determined from the sampled balls, prior to hardness testing, or from the whole batch. The following chemical composition is recommended: — tungsten carbide (WC): balance; — total other carbides: 2,0 %; — cobalt (Co): 5,0 % to 7,0 %. 4.4 Calibration of the indentation diameter measuring system 4.4.1 For systems where the indentation diameter is measured directly, the scale of the system shall be graduated to permit estimation of the diameter to within ±0,5 %. The indentation diameter measuring system shall be calibrated for every objective lens, and for each incorporated line scale, in two perpendicular measurement axes (if applicable), by measurements made on a standard scale at a minimum of four intervals, arranged centrally in the field of view, for each working range. For each measurement, the magnitude of the difference between the measured and reference values shall not be greater than 0,5 % (see Formula A.7). 4.4.2 For systems where the indentation diameter is calculated from a measurement of projected area, the system shall be calibrated for every objective lens by measurements of a range of at least four standard circular reference images covering the range of areas measured. The maximum error shall not exceed 1 % of the area. 4.4.3 All systems shall also be verified by making measurements of certified reference indentations, such as those on hardness reference blocks calibrated in accordance with ISO 6506-3.