JIS-Z-2244-2003-ENG.pdf
J IS JAPANESE I N DUSTR IAL STANDARD Translated and Published by Ja pan ese Stand a rds Association JIS Z 22442003 (JISF/ JSA) Vickers hardness test-Test method ICs 77.040; 10 Reference number : JIS Z 2244 : 2003 (E) PROTECTED BY COPYRIGHT 59 s Z 2244 : 2003 Foreword This translation has been made based on the original Japanese Industrial Standard revised by the Minister of Economy, Trade and Industry through deliberations at the Japanese Industrial Standards Committee, as the result of proposal for revision of Japanese Industrial Standard submitted by The Japan Iron and Steel Federation (JISF)/the Japanese Standards Association (JSA) with the draft being attached, based on the provision of Article 12 Clause 1 of the Industrial Standardization Law applicable to the case of revision by the provision of Article 14. Consequently, JIS 2 2244 : 1998 is replaced with this Standard. Date of Establishment: 1952-06-21 Date of Revision: 2003-03-20 Date of Public Notice in Official Gazette: 2003-03-20 Investigated by: Japanese Industrial Standards Committee Standards Board Technical Committee on Iron and Steel TIS Z 2244 : 2003, First English edition published in 2003-07 Translated and published by: Japanese Standards Association 4-1-24, Akasaka, Minato-ku, Tokyo, 107-8440 JAPAN In the event of any doubts arising as to the contents, the original JIS is to be the final authority. O JSA 2003 Ali 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 the publisher. Printed in Japan PROTECTED BY COPYRIGHT Contents Z 2244 : 2003 Page Introduction . 1 2 3 4 4.1 4.2 5 6 7 8 9 Scope Normative reference Principle Symbols and denotation of hardness . Symbols . Denotation of hardness . Testing machine . Test piece Test Uncertainty of the results . Test report Annex A (normative) Annex B (normative) Annex C (normative) Minimum thickness of the test piece in relation to the test force and to the hardness Tables of correction factors for use in tests made on curved surfaces . Tables of Vickers hardness values Annex D (informative) Monitoring the uncertainty of the hardness testing machines by the users . 103 Annex 1 (informative) Comparison table between JIS and corresponding International Standard . 104 (i) PROTECTED BY COPYRIGHT -,-,- JAPANESE INDUSTRIAL STANDARD JIS Z 2244 : 2003 Vickers hardness test-Test method Introduction This Japanese Industrial Standard has been prepared based on IS0 6507-1 Metallic materials-Vickers hardness test-Part 1 : Test method published in 1997, without modification in the technical contents, but with some additions of normative items that are not specified in the corresponding International Standard. In this Standard, portions underlined with dots are matters that are not included in the original International Standard. List of modifications with their explanations is shown in the Annex 1 (informative). 1 Scope This Standard specifies the Vickers hardness test method mainly for the metallic materials the test force of which is 98.07 mN or more. The Vickers hardness test is specified in this Standard for lengths of indentation diagonals between 20 pm and 1.400 pm. Remarks 1 For specific materials and products, particular standards exist. 2 The Vickers hardness test for the lengths of indentation diagonals less than 20 pm and the test force of less than 98.07 mN shall con- form to this Standard. . 3 The International Standard corresponding to this Standard is as follows. In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standard and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) ac- cording to ISODEC Guide 21. IS0 6507-1 : 1997 Metallic materials-Vickers hardness test-Part 1 : Test method (MOD) 2 Normative reference The following standard contains provisions which, through reference in this Standard, constitute provisions of this Standard. The most recent edition of the standard indicated below (including amendments) shall be applied. JIS B 7725 Vickers hardness test-Verification of testing machines Remarks : IS0 6507-2 : 1997 Metallic materials-Vickers hardness test-Part 2 : Verification of testing machines is equivalent to the said standard. 3 Principle A diamond indenter in the form of a right pyramid with a square base and with a specified angle between opposite faces at the vertex is forced into the surface of a test piece followed by measurement of the diagonal length of the indentation left in the surface after removal of the test force, F (see Figure i). The Vickers hardness is proportional to the quotient obtained by dividing the test force by the sloping area of the indentation which is assumed to be a right pyramid with a square base, and having at the vertex the same angle as the indenter. PROTECTED BY COPYRIGHT -,-,- 2 Z 2244 : 2003 a) Vickers indenter Figure 1 b) Vickers indentation Principle of the test 4 Symbols and denotation of hardness 4.1 Symbols Symbols and their definitions are given in Table 1 (see Table 1 Symbols and their definitions Symbol F Definition Angle between the opposite faces at the vertex of the pyramidal indenter (136') Test force, in newtons Arithmetic mean, in millimeters, of the two diagonals length dl and dz (see Figure i) Test force Surface area of indentation Vickers hardness = Constant x 136“ 2Fsin- 2 F %0.189 1 - d2 d2 = 0.102 x %0.102 1 NOTE: Constant = - = g, 9.80665 Figure i). 4.2 preceded by the hardness value followed by a) b) Denotation of hardness The Vickers hardness is denoted by the symbol HV a number representing the test force (see Table 2); the duration of loading, in seconds, if different from the time specified in 7 d). EXAMPLES 1 2 640 HV30 = Vickers hardness of 640 determined with a test force of 294.2 N applied for 10 s to 15 s. 640 HV30/20 = Vickers hardness of 640 determined with a test force of 294.2 N applied for 20 s. 5 Testing machine The testing machine shall be as follows: a) Testing machine, capable of applying a predetermined force within the required range of test forces, in accordance with JIS B 7725. PROTECTED BY COPYRIGHT -,-,- 3 Z 2244 : 2003 b) c) Indenter, as specified in JIS B 7725. Measuring device, as specified in JIS B 7725. NOTE : A recommended procedure for monitoring the uncertainty of the hard- ness testing machine by the users is given in Annex D. 6 Test piece The test piece shall be as follows: a) The test shall be carried out on a surface which is smooth and even, free from oxide scale, foreign matter and, in particular, completely free from lubricants, unless otherwise specified in product standards. The finish of the surface shall permit accurate determination of the diagonal length of the indentation. Preparation shall be carried out in such a way that any alteration of the sur- face hardness, due to heat or cold-working, for example, is minimized. Due to the small depth of Vickers microhardness indentations, it is essential that special precautions are taken during preparation. It is recommended to use a polishing/electropolishing process which is suitable for the material pa- rameters. The thickness of the test piece or of the layer under test shall be at least 1.5 times the diagonal length of the indentation (see Annex A). No deformation shall be visible at the back of the test piece after the test. For tests on curved surfaces, the corrections given in Tables B.l to B.6 shall be applied to convert the apparent hardness to the corresponding hardness of the flat surface. For test pieces of small cross-section or of irregular shape, it may be necessary to provide some form of additional support. Information : In the preparation and testing of the test piece of small dimen- sion or of complicated shape, it is recommended to hold it by using particular holders or by embedding it in resin. However, the method employed shall not affect the hardness of the test piece. When embedding the test piece in resin, care shall be taken because the heat generation along with hardening of resin, and pressure and temperature during press forming may affect the hardness of the test piece. b) c) d) e) . . . . 7 Test The test shall be as follows: a) In general, the test is carried out at ambient temperature within the limits of 10 “C to 35 O C . Tests carried out under controlled conditions shall be made at a temperature of (23 i . 5) “C. The test force shall be as given in Table 2. Other test forces than those in Table 2 are allowed to be used. b) PROTECTED BY COPYRIGHT -,-,- 4 Z 2244 : 2003 Material of test piece Table 2 Correspondence between hardness symbols and test forces Steel, nickel alloys, titanium alloys, copper and copper alloys Light metal, lead, tin and their alloys Hardness symbol Hvo.01 HV0.015 Hv0.02 HV0.025 mo:!?!? Hv0.05 Hvo.l Distance between the centre of indentations* Nominal value of the test force F N 0.098 07 0.147 1 0.196 1 0.245 2 0:2942 0.490 3 0.980 7 3d min. Hardness symbol Distance from the centre of any indentation to the edge of test piece Hv0.2 Hv0.3 Hv0.5 HV1 Hv2 Hv3 HV5 2.5d min. Nominal value of the test force F N Hardness symbol Nominal value of the test force F N 1.961 2.942 4.903 9.807 19.61 29.42 49.03 HV10 HV20 HV30 HV50 HV100 98.07 196.1 294.2 490.3 980.7 c) The test piece shall be placed on a rigid support. The support surfaces shall be clean and free from foreign matter (scale, oil, dirt, etc.). It is important that the test piece lies firmly on the support so that displacement cannot occur dur- ing the test. Bring the indenter into contact with the test surface and apply the test force in a direction perpendicular to the surface, without shock or vibration, until the applied force attains the specified value. The time from the initial application of the force until the full test force is reached shall not be less than 2 s nor greater than 8 s. For the tests with test forces 29.42 N or less, this time shall not exceed 10 s. For the tests with test forces 29.42 N or less, the approach speed of the indenter shall not exceed 0.2 mm/s. If a recommended condition is provided to the testing machine, that condi- tion mav be amlied. d) . . I LA . The duration of the test force shall be 10 s to 15 s. For particular materials, a longer time for maintaining the force is provided; this time shall be applied with a tolerance of A 2 s. Throughout the test, the testing machine shall. be protected from shock or vi- bration. The distance between the centres of two adjacent indentations and the distance between the centre of any indentation and the edge of the test piece shall be as given in Table 3 in relation to the mean diagonal length of the indentation d. e) f) Table 3 Position of indentation 6d min. 3d min. Note * If the adjacent indentations differ in sizes, d shall be the arithmetical mean of the diagonals of the larger indentation. PROTECTED BY COPYRIGHT -,-,- 5 Z 2244 : 2003 g) Measure the lengths of the two diagonals. The arithmetical mean of the two readings shall be taken for the calculation of the Vickers hardness. For flat surfaces, the difference between the lengths of two indentation di- agonals should not be greater than 5 %. If the difference is greater, this shall be stated in the test report. Remarks : Calculated values of hardness according to the formula of Vickers hardness in Table 1 are shown in Tables C.l to C.3. . 8 Uncertainty of the results The uncertainty of results is dependent on vari- ous parameters which may be separated into two categories: a) parameters depending on the Vickers hardness testing machine (including the uncertainty of the verification of the testing machine and of the calibration of the reference blocks); parameters depending on the application of the test method (variation of the operating conditions). Remarks 1 It is recommended that the complete evaluation of the uncertainty is in accordance with IS0 Guide GUM (Guide to the expression of uncertainty in measurement). 2 It may be assumed that the expanded uncertainty with 95 % con- fidence level of the uncertainty corresponding to a) is equivalent to the tolerances of errors of hardness of the testing machines shown in Table 7 of JIS B 7725. b) 9 Test report The test report shall include the following information: reference to this Standard; all details necessary for identification of the test piece; the result obtained; all operations not specified by this Standard, or regarded as optional; details of any occurrence which may have affected the results; the temperature of the test, if it is outside the range specified in 7 a). NOTES 1 2 A strict comparison of hardness values is only possible at identical test forces. There is no general process of accurately converting Vickers hardness into other scales of hardness or into tensile strength. Such conversions there- fore should be avoided, unless a reliable basis for conversion can be obtained by comparison tests. It should be noted that for anisotropic materials, for example those which have been heavily cold-worked, there will be a difference between the lengths of the two diagonals of the indentation. Where possible, the indentation should be made so that the diagonals are inclined at approximately 45“ to the direction of cold-working. 3 PROTECTED BY COPYRIGHT -,-,- 6 Z 2244 : 2003 Information 1 2 The specification for the product may indicate limits for the differences between the lengths of the two diagonals. There is evidence that some materials may be sensitive to the rate af straining which causes small changes in the value of the yield stress. The corresponding effect on the termination of the formation of an indentation can make alter- ations in the hardness value. PROTECTED BY COPYRIGHT 7 Z 2244 : 2003 Annex A (normative) Minimum thickness of the test piece in relation to the test force and to the hardness This nomogram has been designed for the minimum thickness of a test piece, as- suming that the minimum thickness has to be ten times or more the depth of the indentation. The required thickness is given by the point of intersection of the minimum thickness scale and a line (shown by a long dashed short dashed line in the example) joining the test force (right-hand scale) with the hardness (left-hand scale). Vickers hardness HV 2ooo F 1 O00 300 2oo b l o o t 50 I- 20 30 E - Hardness symbol HV 0.001 Minimum Diagonal thickness length of of test piece indentation 0.002 0.003 0.00 1 0.005 0 . 0 1 mm mm 0.00 1 0.002 0.003 0.005 0.02 0.03 0.005 0.0 1 0.05 o. 1 0.02 1 0.03 0.02 0.05 3 '.O3 0 . í O3 0.5 1 -.- I - . 0.2 r L c E 1C 2 c
