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1、 AS 1815.22007 ISO 6508-2:2005 Australian Standard Metallic materialsRockwell hardness test Method 2: Verification and calibration of testing machine (scales A, B, C, D, E, F, G, H, K, N, T PREFACE This Standard was prepared by the Standards Australia Committee MT-006, Mechanical Testing of Metals t
2、o supersede in part AS 1815.22002, Metallic materialsRockwell hardness test, Method 2: Verification and calibration of testing machines (scales A, B, C, D, E, F, G, H, K, N, T). This Standard is identical with, and has been reproduced from ISO 6508-2:2005, Metallic materialsRockwell hardness test, M
3、ethod 2: Verification and calibration of testing machines (scales A, B, C, D, E, F, G, H, K, N, T). The objective of this Standard is to specify the method for verification and calibration of Rockwell hardness testing machines. AS 1815 Metallic materialsRockwell hardness test 1815.1 Method 1: Test m
4、ethod scales (scales A,B,C,D,E,F,G,H,K,N,T) 1815.2 Method 2: Verification and calibration of testing machines (scales A,B,C,D,E,F,G,H,K,N,T) (this Standard) 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
5、test 1816.1 Method 1: Test method (ISO 6506-1:1999, MOD) 1816.2 Method 2: Verification and calibration of testing machines 1816.3 Method 3: Calibration of reference blocks 1816.4 Method 4: Table of hardness values 1817 Metallic materialsVickers hardness test 1817.1 Method 1: Test method (ISO 6507-1:
6、1997, MOD) 1817.2 Method 2: Verification of testing machines 1817.3 Method 3: Calibration of reference blocks 5016 Metallic materialsConversion of hardness values As this Standard is reproduced from an International Standard, the following applies: (a) Its number does not appear on each page of text
7、 and its identity is shown only on the cover and title page. (b) In the source text this part of ISO 6508 should read this Australian Standard. (c) A full point should be substituted for a comma when referring to a decimal marker. AS 1815.22007 i i References to International Standards should be rep
8、laced by references to Australian Standards as follows: Reference to International 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 6507
9、 Metallic materialsVickers hardness test 1817 Metallic materialsVickers hardness test 6507-1 Part 1: Test method 1817.1 Method 1: Test method (ISO 6507- 1:1997, MOD) 6508 Metallic materialsRockwell hardness test 1815 Metallic materialsRockwell hardness test 6508-1 Part 1: Test method (scales A, B, C
10、, D, E, F, G, H, K, N, T) 1815.1 Method 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T) 6508-3 Part 3: Calibration of reference blocks (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) The
11、 terms normative and informative have been used in this Standard to define the application of the annex to which they apply. A normative annex is an integral part of a standard, where an informative annex is only for information and guidance. ii ii The Standard is downloaded from Standard Sharing I
12、NTERNATIONAL STANDARD ISO 6508-2:2005(E) ISO 2005 All rights reserved 1 Metallic materials Rockwell hardness test Part 2: Verification and calibration of testing machines (scales A, B, C, D, E, F, G, H, K, N, T) 1 Scope This part of ISO 6508 specifies a method of verification of testing machines for
13、 determining Rockwell hardness (scales A, B, C, D, E, F, G, H, K, N, T) in accordance with ISO 6508-1. It specifies a direct method for checking the main functions of the machine operation and an indirect method suitable for the overall checking of the machine. The indirect method may be used on its
14、 own for periodic routine checking of the machine in service. If a testing machine is also to be used for other methods of hardness testing, it shall be verified independently for each method. This part of ISO 6508 is applicable to portable hardness testing machines. 2 Normative references The follo
15、wing 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-prov
16、ing instruments used for verification of uniaxial testing machines ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test method ISO 6508-1, Metallic materials Rockwell hardness test Part 1: Test method (scales A, B, C, D, E, F, G, H, K, N, T) ISO 6508-3:2005, Metallic materials Rockwell
17、hardness test Part 3: Calibration of reference blocks (scales A, B, C, D, E, F, G, H, K, N, T) 3 General conditions Before a Rockwell hardness testing machine is verified, the machine shall be checked to ensure that it is properly set up in accordance with the manufacturers instructions: Especially
18、it should be checked that: a) the plunger holding the indenter is capable of sliding in its guide; 1 1 ISO 6508-2:2005(E) 2 ISO 2005 All rights reserved b) the indenter-holder is firmly mounted in the plunger; c) the test force can be applied and removed without shock or vibration and in such a mann
19、er that the readings are not influenced. It shall be checked that the readings are not affected either by movements of the test piece or by deformation of the frame. When a device is supplied, which locks the test piece against the upper part of the frame, the locking force shall exceed the total te
20、st force. The influence of deformations may be checked by using a plunger with a spherical tip (diameter of at least 10 mm), instead of the indenter, bearing against the anvil through a spacer and using the locking device when it is supplied. The material of the plunger and of the spacer have a hard
21、ness of at least 60 HRC. The readings of the measuring system (with preliminary force applied) before application and after removal of the additional force shall not differ by more than 1,5 Rockwell units (without locking equipment) and 0,5 Rockwell units (with locking equipment). 4 Direct verificat
22、ion 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 of this temperature range, this shall be reported in the verification report. 4.1.2 The instruments used for verification and calibration shall be traceable to national s
23、tandards. 4.1.3 Direct verification involves: a) calibration of the test force; b) verification of the indenter; c) calibration of the depth-measuring system; d) verification of the testing cycle. 4.2 Calibration of the test force 4.2.1 The preliminary test force F0 (see 4.2.4) and each total test f
24、orce F used (see 4.2.5) shall be measured, and, whenever applicable, this shall be done at not less than three positions of the plunger spaced throughout its range of movement during testing. The preliminary test force shall be held for at least 2 s. 4.2.2 Three readings shall be taken for each forc
25、e at each position of the plunger. Immediately before each reading is taken, the plunger shall be moved in the same direction as during testing. 4.2.3 The forces shall be measured by one of the following two methods: by means of a force proving device in accordance with ISO 376:2004, class 1, or by
26、balancing against a force, accurate to 0,2 %, applied by means of calibrated masses or by another method having the same accuracy. 4.2.4 The tolerance on the preliminary test force F0 (before application and after removal of the additional test force F1) shall be 2,0 %. 4.2.5 The tolerance on the to
27、tal test force F shall be 1,0 %. Each individual value of F shall be within this tolerance. 2 2 The Standard is downloaded from Standard Sharing ISO 6508-2:2005(E) ISO 2005 All rights reserved 3 4.3 Verification of the indenter 4.3.1 Diamond cone indenter (scales A, C, D, N) To verify the reliable
28、performance of the conical indenter in conformance with this part of ISO 6508, a direct and an indirect verification shall be carried out. 4.3.1.1 Direct verification 4.3.1.1.1 The surfaces of the diamond cone and spherical tip shall be polished for a penetration depth of 0,3 mm and shall blend in a
29、 truly tangential manner. Both surfaces shall be free from surface defects. 4.3.1.1.2 The verification of the shape of the indenter can be made by direct measurement or by measurement of its projection on a screen. The verification shall be made at not less than four equally spaced sections. 4.3.1.1
30、.3 The diamond cone shall have an included angle of (120 0,35). Deviations from straightness of the generatrix of the diamond cone, adjacent to the blend, shall not exceed 0,002 mm over a minimum length of 0,4 mm. 4.3.1.1.4 The angle between the axis of the diamond cone and the axis of the indenter-
31、holder (normal to the seating surface) shall not exceed 0,5. 4.3.1.1.5 The tip of the indenter shall be spherical. Its radius shall be determined from single values, measured in the axial section planes defined in 4.3.1.1.2. The distance between the concentric circles shall be no more than 0,004 mm.
32、 Each single value shall be within (0,2 0,015) mm. The mean value out of at least four single values shall be within (0,2 0,01) mm. NOTE 1 The radius can be obtained by determining the intersection of two segments of the concentric circles. NOTE 2 The single value is the mean value of the two radii
33、of the concentric circles. Measurement with a collimator device is also available. In this case, the measurements should be carried out at least in four central angles and the central angle of 120 must be included. 4.3.1.2 Indirect verification The hardness values given by the testing machine depend
34、 not only on the dimensions given in 4.3.1.1.3 and 4.3.1.1.5, but also on the surface roughness and the position of the crystallographic axes of the diamond, and the seating of the diamond in its holder. To examine this influence, the indirect verification of the indenter shall be performed on four
35、reference blocks which shall be calibrated for the hardness levels given in Table 1 or on blocks giving equivalent total depths of indentation. Table 1 Hardness levels for different scales Scale Hardness Ranges HRC 23 20 to 26 HRC 55 52 to 58 HR45N 43 40 to 46 HR15N 91 88 to 94 3 3 ISO 6508-2:2005(E
36、) 4 ISO 2005 All rights reserved For each block, the mean hardness value of three indentations made using the indenter to be verified shall not differ from the mean hardness value of the three indentations obtained with the indenter, calibrated in accordance with 4.5 of ISO 6508-3:2005 by more than
37、0,8 Rockwell units. The indentations made with the indenter to be verified and with the above-mentioned indenter should be adjacent. NOTE This can be performed with a calibration machine in accordance with the procedure described in Clause 5 of ISO 6508-3:2005. The hardness testing machines used for
38、 this indirect verification shall comply with the following tolerances for the test forces: F0: 1,0 % F : 0,5 % The test shall be carried out in accordance with ISO 6508-1. 4.3.2 Ball indenter (scales B, E, F, G, H, K, T) 4.3.2.1 For the purpose of verifying the size and the hardness of the balls, o
39、ne sample selected at random from a batch shall be tested. The balls verified for hardness shall be discarded. 4.3.2.2 The balls shall be polished and free from surface defects. 4.3.2.3 The user shall either measure the balls to ensure that they meet the following requirements, or shall obtain balls
40、 from a supplier certifying that the following conditions are met. 4.3.2.3.1 The diameter, measured at no less than three positions, shall not differ from the nominal diameter by more than the tolerance given in Table 2. Table 2 Tolerances for the different ball diameters Rockwell hardness scale Bal
41、l diameter mm Tolerance mm B F G T 1,587 5 1,587 5 1,587 5 1,587 5 0,003 5 0,003 5 0,003 5 0,003 5 E H K 3,175 3,175 3,175 0,004 0,004 0,004 4.3.2.3.2 The characteristics of the hardmetal balls shall be as follows: hardness: the hardness shall be no less than 1 500 HV, when determined using a test f
42、orce of at least 4,903 N in accordance with ISO 6507-1. The hardmetal ball may be tested directly on this spherical surface or by sectioning the ball and testing on the ball interior. An example for HV 10 is given in Table 3. density: = (14,8 0,2) g/cm3. NOTE The following chemical composition is re
43、commended: tungsten carbide (WC) balance total other carbides 2,0 % cobalt (Co) 5,0 % to 7,0 % 4 4 The Standard is downloaded from Standard Sharing ISO 6508-2:2005(E) ISO 2005 All rights reserved 5 4.3.2.3.3 The hardness of steel balls shall be no less than 750 HV, when determined using a test forc
44、e of 98,07 N in accordance with ISO 6507-1 (see Table 3). Table 3 Values of the mean diagonal (HV10) for the determination of the hardness of the ball indenters Maximum value of the mean diagonal made on the spherical surface of the ball with a Vickers indenter at 98,07 N (HV10) mm Ball diameter mm
45、Steel ball Hardmetal ball 3,175 1,587 5 0,153 0,150 0,109 0,107 4.4 Calibration of the depth-measuring system 4.4.1 The depth-measuring system shall be calibrated over no less than three intervals, including the intervals corresponding to the lowest and highest hardness for which the scales are norm
46、ally used, by making known incremental movements of the indenter in the direction of increasing hardness values. 4.4.2 The instrument used to verify the depth-measuring system shall have an accuracy of 0,000 2 mm. The depth-measuring system shall correctly indicate within 0,001 mm for the scales A t
47、o K and within 0,000 5 mm for scales N and T, i. e. within 0,5 of a scale unit, over each range. NOTE If it is not possible to verify the depth-measuring system directly, its performance can be derived from the results of an indirect verification, using reference blocks and a certified indenter, and
48、 making corrections for known errors (see 5.2). 4.5 Verification of the testing cycle The testing cycle shall conform to the testing cycle given in ISO 6508-1 and shall be timed with an uncertainty less than 0,5 s. 5 Indirect verification 5.1 General Indirect verification should be carried out at a
49、temperature of (23 5) C by means of reference blocks calibrated in accordance with ISO 6508-3. If the verification is made outside of this temperature range, this shall be reported in the verification report. 5.2 Procedure 5.2.1 For the indirect verification of a testing machine, the following procedures shall be applied. The testing machine shall be verified for each scale for which it shall be used. For each scal