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1、AS 1816.3-2007 金属材料.布氏硬度试验.基准块校准 AS 1816.32007 ISO 6506-3:2005 Australian Standard? Metallic materialsBrinell hardness test Method 3: Calibration of reference blocks PREFACE This Standard was prepared by the Standards Australia Committee MT-006, Mechanical Testing of Metals to supersede AS 1816.3200
2、2, Metallic materialsBrinell hardness test, Method 3: Calibration of reference blocks. This Standard is identical with and has been reproduced from ISO 6506-3:2005, Metallic materialsBrinell hardness test, Part 3: Calibration of reference blocks. The objective of this Standard is to specify the meth
3、od for the calibration of reference blocks to be used in the indirect verification of Brinell hardness testing machines. The objective of this edition is to adopt the current edition of ISO 6506-3 to revise the method for the calibration of reference blocks for Brinell hardness testing machines. Thi
4、s Standard is one of a series of Standards covering the range of hardness testing methods. The series comprises of the follow: AS 1815 Metallic materialsRockwell hardness test 1815.1 Method 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T) 1815.2 Method 2: Verification and calibration of testi
5、ng machines (scales A, B, C, D, E, F, G, H, K, N, T) 1815.3 Method 3: Calibration of reference blocks (scales A, B, C, D, E, F, G, H, K, N, T) (ISO 6508-3:2005, MOD) 1816 Metallic materialsBrinell hardness test 1816.1 Method 1: Test methods 1816.2 Method 2: Verification and calibration of testing ma
6、chines 1816.3 Method 3: Calibration of reference blocks (this Standard) 1816.4 Method 4: Table of hardness values 1817 Metallic materialsVickers hardness test 1817.1 Method 1: Test method (ISO 6507-1:1997, MOD) 1817.2 Method 2: Verification of testing machines 1817.3 Method 3: Calibration of referen
7、ce blocks 5016 Metallic materialsConversion of hardness values As this Standard is reproduced from an international standard, the following applies: (a) Its number appears on the cover and title page while the international standard number appears only on the cover. (b) In the source text this part
8、of ISO 6506 should read this Australian Standard. (c) A full point substitutes for a comma when referring to a decimal marker. AS 1816.32007 i.yang64References to International Standards should be replaced by references to Australian or Australian/New Zealand Standards, as follows: Reference to Inte
9、rnational Standard Australian Standard ISO AS 376 Metallic materialsCalibration of force-proving instruments used for verification of uniaxial testing machines 2193 Calibration and classification of force measuring systems 4287 Geometrical production specifications (GPS)Surface texture: Profile meth
10、odsTerms definitions and surface texture parameters 6506 Metallic materialsBrinell hardness test 1816 Metallic materialsBrinell hardness test 6506-1 Part 1: Test method 1816.1 Part 1: Test method (ISO 6506-1:2005, MOD) 6506-2 Part 2: Verification and calibration of testing machines 1816.2 Part 2:Ver
11、ification and calibration of testing machines The term informative has been used in this Standard to define the application of the annex to which it applies. An informative annex is only for information and guidance ii.yang6INTERNATIONAL STANDARD ISO 6506-3:2005(E) ? ISO 2005 All rights reserved 1Me
12、tallic materials Brinell hardness test Part 3: Calibration of reference blocks 1 Scope This part of ISO 6506 specifies a method for the calibration of reference blocks to be used in the indirect verification of Brinell hardness testing machines as described in ISO 6506-2. 2 Normative references The
13、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
14、-proving instruments used for verification of uniaxial testing machines ISO 4287, Geometrical Product Specifications (GPS) Surface texture: Profile method Terms, definitions and surface texture parameters ISO 6506-1:2005, Metallic materials Brinell hardness test Part 1: Test method ISO 6506-2:2005,
15、Metallic materials Brinell 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
16、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: ? 16 mm for 10 mm balls; ? 12 mm for 5 mm balls; ? 6 mm for smaller balls. NOTE 12 mm for 10 mm balls may be used only if the hardness of
17、 the reference block is greater than 150 HBW. 3.3 The reference blocks shall be free of magnetism. It is recommended that the manufacturer shall ensure that the blocks, if of steel, have been demagnetized at the end of the manufacturing process. 1.yang6ISO 6506-3:2005(E) 2 ? ISO 2005 All rights rese
18、rved 3.4 The flatness of the two surfaces and the parallelism of the reference block shall be in accordance with Table 1. Table 1 Requirements for the reference blocks Permissible surface roughness, Ra a ?m Diameter of ball mm Tolerance in flatness of the surfaces mm Tolerance in parallelism mm over
19、 50 mm Test surface Bottom surface 10 5 < 5 0,040 0,030 0,020 0,050 0,040 0,030 0,3 0,2 0,1 0,8 0,8 0,8 a Sampling length: l = 0,80 mm (see ISO 4287). 3.5 The test surface shall be free from scratches which interfere with the measurement of the indentations (see Table 1). 3.6 To verify that no ma
20、terial is subsequently removed from the reference block, the thickness at the time of calibration shall be marked on it to the nearest 0,1 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 i
21、n Clause 3 of ISO 6506-2:2005, the calibration machine shall also meet the requirements given in 4.2 to 4.8. 4.2 The machine shall be verified directly in intervals not exceeding twelve months. Direct verification involves: a) calibration of the test force; b) verification of the indenter; c) calibr
22、ation 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 d
23、evice (of ISO 376:2004, Class 0,5 or better) and the measurement shall agree with the nominal value to within 0,1 %. 4.5 The indenters shall be verified and shall meet the requirements given in 4.3 of ISO 6506-2:2005, with the exception that the tolerances on the diameter of the balls shall meet req
24、uirements given in Table 2. 2.yang6ISO 6506-3:2005(E) ? ISO 2005 All rights reserved 3Table 2 Tolerances for different ball diameters Ball diameter mm Tolerance mm 10 5 2,5 1 0,003 0,002 0,001 0,001 4.6 The scale of the measuring microscope shall be graduated to read to 0,002 mm for indentations mad
25、e with 10 mm and 5 mm balls and 0,001 mm for indentations made with balls of less than 5 mm diameter. The scale of the measuring microscope shall be verified by measurements made on a stage micrometer at a minimum of five intervals over each working range. The accuracy of the measuring device in rel
26、ation to the diameters of indentation shall be as given in Table 3. Table 3 Accuracy of the measuring device Diameter of indentation mm Accuracy mm d < 1 1 u d < 2,5 d W 2,5 0,000 5 0,001 0 0,002 0 4.7 The testing cycle shall conform to the testing cycle described in ISO 6506-1 and shall be ti
27、med with an uncertainty less than 0,5 s. 4.8 The characteristics of the hardmetal balls are specified in 4.3.4.2 of ISO 6506-2:2005. 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 pro
28、cedure described in ISO 6506-1. During calibration, the thermal drift should not exceed 1 C. The time from the initial application of force to the time the full test force is reached shall not be less than 6 s nor greater than 8 s. The duration of the test force shall be 10 s to 15 s. The mechanism
29、which controls the application of the force shall ensure that the speed of approach of the ball immediately before it touches the block is not more than 1 mm/s. 6 Number of indentations On each reference block, five indentations shall be made uniformly distributed over the entire test surface. To re
30、duce the measurement uncertainty, more than five indentations should be made. 3.yang6ISO 6506-3:2005(E) 4 ? ISO 2005 All rights reserved 7 Uniformity of hardness 7.1 Let d1, d2, d3, d4 and d5 be the values of the mean measured diameters of the indentations arranged in increasing order of magnitude.
31、The non-uniformity of the block under the particular conditions of calibration is characterized by U = d5 d1 (1) and is expressed as a percentage of d 5 1rel 100d dUd?= (2) where 1 2 3 4 55d d d d dd + + + += (3) 7.2 The maximum permissible value of non-uniformity of a reference block shall be as sp
32、ecified in Table 4. Table 4 Maximum permissible value of non-uniformity d mm Maximum permissible value of non-uniformity, Urel % d < 0,5 0,5 u d u 1 d > 1 2,0 1,5 1,0 NOTE For a hardness value less than 200 HBW, the maximum permissible value of non-uniformity may be 2,0 %. 7.3 The determinatio
33、n 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 standardizing test, for example: 348 HBW 5/750; b) name or mark of the suppl
34、ier or manufacturer; c) serial number; d) name or mark of the calibration 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 upright when the test s
35、urface is the upper face. 4.yang6ISO 6506-3:2005(E) ? ISO 2005 All rights reserved 58.3 Each delivered reference block shall be accompanied by a document giving at least the following information: a) a reference to this part of ISO 6506; b) the identity of the block; c) the date of calibration; d) t
36、he arithmetic mean of the hardness values and the value characterizing the non-uniformity of the block (see 7.1); e) information about the location of the reference indentation and the orientation of its measured diameters, together with the mean measured diameter. 9 Validity The hardness-reference
37、block is only valid for the scale for which it was calibrated. The calibration validity should be limited to a duration of five years. Attention is drawn to the fact that, for Al- and Cu-alloys, the calibration validity could be reduced to two - three years. 5.yang6ISO 6506-3:2005(E) 6 ? ISO 2005 Al
38、l rights reserved 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 C.1 in ISO 6506-1:2005. A.1 Direct verification of the hardness-calibration machine A.1.1 Calibrat
39、ion of the test force See ISO 6506-2:2005, Annex A. A.1.2 Calibration of the optical measuring device See ISO 6506-2:2005, Annex A. A.1.3 Verification of the indenter See ISO 6506-2:2005, Annex A. A.1.4 Verification of the test cycle See ISO 6506-2:2005, Annex A. A.2 Indirect calibration of the hard
40、ness-calibration machine NOTE In this annex, the index “CRM (Certified Reference Material)” means, according to the definitions of the hardness testing standards, “Hardness Reference Block”. By the indirect verification with primary hardness-reference blocks, the overall function of the hardness-cal
41、ibration machine is checked and the repeatability as well as the deviation of the hardness-calibration machine from the actual hardness value are determined. The uncertainty of measurement of the indirect calibration of the hardness-calibration machine follows from the equation: 2 2 2 2CM CRM P CRM
42、1 CRM D msxu u u u u? ? ?= + + + (A.1) where uCRM-P is the calibration uncertainty of the primary hardness-reference block according to the calibration certificate for k = 1; u-xCRM-1 is the repeatability of the hardness-calibration machine; uCRM-D is the hardness change of the primary hardness-refe
43、rence block since its last calibration due to drift; ums is the standard uncertainty due to the resolution of the optical measuring device. 6.yang6ISO 6506-3:2005(E) ? ISO 2005 All rights reserved 7EXAMPLE Primary hardness-reference block: (5791,7 3,6) HBW 2,5/187,5 Uncertainty of measurement of the
44、 primary hardness-reference block uCRM-1 = 1,8 HBW 2,5/187,5 Time drift of the primary hardness-reference block uCRM-D = 0 Resolution of the measuring device ms = 0,1 ?m Table A.1 Results of the indirect verification Number Measured indentation diameter, d mm Calculated hardness value, H HBW 1 0,630 5max 591,4min 2 0,630 0 592,3 3 0,629 5min 593,3max 4 0,629 7 592,9 5 0,629 5 593,3 Mean value H 0,629 8 592,6 Standard deviation sxCRM1 0,000 42 0,81 HBW: Brinell hardness CRM 1CRM 1 0 41xxt su ,n?= = (A.2) (t = 1,14 for n = 5) Table A.2 Budget of uncertainty of measurement Quantity