BS-EN-ISO-6507-3-2005.pdf

BRITISH STANDARD BS EN ISO 6507-3:2005 Metallic materials Vickers hardness test Part 3: Calibration of reference blocks The European Standard EN ISO 6507-3:2005 has the status of a British Standard ICS 77.040.10 ? BS EN ISO 6507-3:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 20 January 2006 © BSI 20 January 2006 ISBN 0 580 47587 5 National foreword This British Standard is the official English language version of EN ISO 6507-3:2005. It is identical with ISO 6507-3:2005. It supersedes BS EN ISO 6507-3:1998 which is withdrawn. The UK participation in its preparation was entrusted by Technical Committee ISE/NFE/4, Mechanical testing of metals, to Subcommittee ISE/NFE/4/5, Indentation hardness testing, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii to iv, pages 1 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN ISO 6507-3 December 2005 ICS 77.040.10Supersedes EN ISO 6507-3:1997 English Version Metallic materials - Vickers hardness test - Part 3: Calibration of reference blocks (ISO 6507-3:2005) Matériaux métalliques - Essai de dureté Vickers - Partie 3: Etalonnage des blocs de référence (ISO 6507-3:2005) Metallische Werkstoffe - Härteprüfung nach Vickers - Teil 3: Kalibrierung von Härtevergleichsplatten (ISO 6507- 3:2005) This European Standard was approved by CEN on 14 December 2005. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels © 2005 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 6507-3:2005: E Foreword This document (EN ISO 6507-3:2005) has been prepared by Technical Committee ISO/TC 164 “Mechanical testing of metals“ in collaboration with Technical Committee ECISS/TC 1 “Steel - Mechanical testing“, 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 June 2006, and conflicting national standards shall be withdrawn at the latest by June 2006. This document supersedes EN ISO 6507-3:1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 6507-3:2005 has been approved by CEN as EN ISO 6507-3:2005 without any modifications. EN ISO 6507-3:2005 Reference number ISO 6507-3:2005(E) INTERNATIONAL STANDARD ISO 6507-3 Third edition 2005-12-15 Metallic materials Vickers hardness test Part 3: Calibration of reference blocks Matériaux métalliques Essai de dureté Vickers Partie 3: Étalonnage des blocs de référence EN ISO 6507-3:2005 ii iii Contents Page Foreword iv 1 Scope . 1 2 Normative references. 1 3 Manufacture of reference blocks 1 4 Calibration machine 2 5 Calibration procedure. 4 6 Number of indentations 4 7 Uniformity of hardness. 4 8 Marking 5 9 Validity . 5 Annex A (informative) Uncertainty of the mean hardness value of hardness-reference blocks. 6 Bibliography. 9 EN ISO 6507-3:2005 iv 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. International Standards 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 International 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 6507-3 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee SC 3, Hardness testing. This third edition cancels and replaces the second edition (ISO 6507-3:1997), which has been technically revised. ISO 6507 consists of the following parts, under the general title Metallic materials Vickers hardness test: Part 1: Test method Part 2: Verification and calibration of testing machines Part 3: Calibration of reference blocks Part 4: Tables of hardness values EN ISO 6507-3:2005 1 Metallic materials Vickers hardness test Part 3: Calibration of reference blocks 1 Scope This part of ISO 6507 specifies a method for the calibration of reference blocks to be used for the indirect verification of Vickers hardness testing machines, as specified in ISO 6507-2. The method is applicable only for indentations with diagonals W 0,020 mm. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 376:2004, Metallic materials Calibration of force-proving instruments used for the verification of uniaxial testing machines ISO 4287:1997, Geometrical Product Specifications (GPS) Surface texture: Profile method Terms, definitions and surface texture parameters ISO 6507-1:2005, Metallic materials Vickers hardness test Part 1: Test method ISO 6507-2:2005, Metallic materials Vickers hardness test Part 2: Verification and calibration of testing machines 3 Manufacture of reference blocks 3.1 The block shall be specially manufactured for use as a hardness-reference block. NOTE Attention is drawn to the need to use a manufacturing process which will give the necessary homogeneity, stability of structure and uniformity of surface hardness. 3.2 Each metal block to be calibrated shall be of a thickness not less than 5 mm. 3.3 The reference blocks shall be free of magnetism. lt is recommended that the manufacturer shall ensure that the blocks, if made of steel, have been demagnetized at the end of the manufacturing process. 3.4 The maximum deviation in flatness of the test and support surfaces shall not exceed 0,005 mm. The maximum error in parallelism shall not exceed 0,010 mm in 50 mm. 3.5 The test surface shall be free from scratches which interfere with the measurement of the indentations. The surface roughness Ra shall not exceed 0,000 05 mm for the test surface and 0,000 8 mm for the bottom surface. The sampling length l shall be 0,80 mm (see ISO 4287:1997, 3.1.9). EN ISO 6507-3:2005 2 3.6 To verify that no material has been subsequently removed from the reference block, its thickness at the time of calibration shall be marked on it, to the nearest 0,01 mm, or an identifying mark shall be made on the test surface see 8.1 e). 4 Calibration machine 4.1 In addition to fulfilling the general requirements specified in ISO 6507-2, the calibration machine shall also meet the requirements of 4.2 to 4.7. 4.2 The calibration machine shall be verified directly at intervals not exceeding 12 months. Direct verification involves a) verification of the test force; b) verification of the indenter; c) verification of the measuring device; d) verification of the testing cycle; if this is not possible, at least the force versus time behaviour. 4.3 The instruments used for verification and calibration shall be traceable to national standards. 4.4 Each test force shall be measured using an elastic proving device (or ISO 376:2004, Class 0.5 or better), or by another method having the same or better accuracy. This measurement shall agree with the nominal value to within ± 0,1 % for normal and low-force hardness, and to within ± 0,5 % for microhardness. 4.5 The indenter shall meet the following requirements: a) The four faces of the square-based diamond pyramid shall be highly polished, free from surface defects, and flat within 0,000 3 mm. b) The angle between the opposite faces of the vertex of the diamond pyramid shall be 136° ± 0,1°. The angle between the axis of the diamond pyramid and the axis of the indenter-holder (normal to the seating surface) shall be less than 0,3°. c) The point of the diamond indenter shall be examined with a high-power measuring microscope or preferably with an interference microscope and, if the four faces do not meet at a point, the line of junction between opposite faces shall comply with the values in Table 1. Table 1 Ranges of test force, F Maximum permissible length of the line of junction, a N mm F W 49,03 0,001 1,961 u F 0,200 0,000 5 mm 0,000 1 mm The measuring device shall be verified by measurements made on an object micrometer at a minimum of five intervals over each working range. The maximum permissible error shall not exceed the values given in Table 2. EN ISO 6507-3:2005 4 5 Calibration procedure The reference blocks shall be calibrated in a calibration machine as described in Clause 4, at a temperature of (23 ± 5) °C, using the general procedure specified in ISO 6507-1. During calibration, the thermal drift should not exceed 1 °C. The time from the initial application of force until the full test force is reached, and the approach velocity of the indenter, shall meet the requirements given in Table 3. The duration of application of the test force shall be 13 s to 15 s. For microhardness testing, the maximum allowable vibrational acceleration reaching the calibration machine shall be 0,005 gn (gn equals the standard acceleration of free fall: gn = 9,806 65 m/s2). Table 3 Ranges of test force, F Time for application of the test forceApproach velocity of the indenter N s mm/s F 225 HV 4,0 or 0,001 mm b 2,0 1,0 a For hardness values 150 HV, the maximum permissible value of non-uniformity shall be 8 % or 0,001 mm, whichever is greater. b Whichever is greater. 7.3 The determination of the uncertainty of measurement of hardness reference blocks is given in Annex A. 8 Marking 8.1 Each reference block shall be marked with the following particulars: a) arithmetic mean of the hardness values found in the calibration test, for example 249 HV 30; b) name or mark of the supplier or manufacturer; c) serial number; d) name or mark of the calibrating agency; e) thickness of the block, or an identifying mark on the test surface (see 3.6); f) year of calibration, if not indicated in the serial number. 8.2 Any mark put on the side of the block shall be the right way up when the test surface is the upper face. 8.3 Each delivered reference block shall be accompanied with a document giving at least the following information: a) a reference to this part of ISO 6507; b) identity of the block; c) date of calibration; d) arithmetic mean of the hardness values and the value characterizing the non-uniformity of the block; e) information about the location of the reference indentation, together with the mean measured diagonal length. 9 Validity The reference block is only valid for the scale for which it was calibrated. The calibration validity should be limited to a duration of 5 years. Attention is drawn to the fact that, for Al- and Cu-alloys, the calibration validity could be reduced to 23 years. EN ISO 6507-3:2005 6 Annex A (informative) Uncertainty of the mean hardness value of hardness-reference blocks The metrological chain necessary to define and disseminate hardness scales is shown in Figure D.1 in ISO 6507-1:2005. A.1 Direct verification of the hardness-calibration machine A.1.1 Calibration of the test force See ISO 6507-2:2005, Annex C. A.1.2 Calibration of the optical measuring device See ISO 6507-2:2005, Annex C. A.1.3 Verification of the indenter See ISO 6507-2:2005, Annex C. A.1.4 Verification of the test cycle See ISO 6507-2:2005, Annex C. A.2 Indirect calibration of the hardness-calibration machine NOTE In this Annex, the index “CRM (Certified Reference Material)”