This standard specifies the test method for Vickers hardness tester used for determination of Vickers hardness according to GB/T 4340.1. This standard describes the direct test method for testing the basic function of the hardness tester and the indirect test method suitable for comprehensive test of the hardness tester. GB/T 4340.2-1999 Metal Vickers hardness test Part 2: Test of hardness tester GB/T4340.2-1999 Standard download decompression password: www.bzxz.net

GB/T 4340. 2 -- 1999
Metal Part 2: Hardness Tester
This standard is formulated by combining and revising the original two national standards of "Vickers Hardness Tester" on the basis of the new international standard IS06507-2:1997 "Inspection of Vickers Hardness Test for Metallic Materials". The overall structure, level division, writing method and technical content of this standard are completely consistent with ISO6507-2:1997, and conform to the provisions of the national standard GB/T 1 "Guidelines for Standardization Work" series of standards. This standard has the following minor differences in editing with the international standard ISO6507-2 that is equivalent to it: a) Foreword is added.
b) Since the international standards cited in Chapter 2 "Referenced Standards" of ISO6507-2 have been transformed into Chinese standards to varying degrees, the corresponding Chinese standards are directly cited in Chapter 2 "Referenced Standards" of this standard. c) Some terms, such as "indication repeatability error" and "indication error" use the customary terms of testing machines in my country. This standard has made the following revisions to the original two independent "Vickers hardness tester" national standards GB/T7664-1987 "Technical conditions for Vickers hardness tester" and GB/T17198-1997 "Verification of Vickers hardness tester (less than HV0.2)": 1. In line with the overall structural changes in the international standard for "Vickers hardness test", the two different national standards GB/T7664-1987 and GB/T17198-1997 have been merged into one standard - Part 2 of GB/T4340. GB/T4340, under the general title of "Metal Vickers hardness test", consists of the following three parts: Part 1: Test method; Part 2: Verification of hardness tester; Part 3: Calibration of standard hardness block. 2. The scope of application is supplemented with the provisions of small-force Vickers hardness testers with a test force range of 1.961~~<49.03N. 3. The indicators of the estimated ability of the indentation measuring device are partially modified (see Table 3). 4. The indicators of the repeatability error of the hardness tester (see Table 4) and the error of the hardness tester (see Table 5) are partially modified. 5. The provisions of coaxiality, verticality, inspection rules, completeness, marking, packaging and random documents of the Vickers hardness tester with a test force range of 49.03980.7N are cancelled to keep consistent with ISO6507-2. 6. Chapter 6 (Inspection cycle), Appendix A (Example of indirect inspection method for measuring devices) and Appendix B (Precautions for diamond indenters) are newly added.
This standard is promoted from the date of implementation and replaces GB/T7664-1987 and GB/T17198--1997 at the same time. Appendix A and Appendix B of this standard are both indicative appendices. This standard is proposed by the State Machinery Industry Bureau. This standard is under the jurisdiction of the National Technical Committee for Standardization of Testing Machines. The responsible drafting unit of this standard is Changchun Testing Machine Research Institute. Participating drafting units are Shanghai Material Testing Machine Factory and China Institute of Metrology. The main drafters of this standard are Wang Xuezhi, Rong Zongze and Li Zhijuan. 380
GB/T 4340.2--- 1999
ISOForeword
ISO (International Organization for Standardization) is a worldwide federation composed of national standardization bodies (ISO Consistent Bodies). The work of formulating international standards is usually completed by ISO's technical committees. Each member body has the right to participate in the work of the committee if it is interested in the standard items established by a technical committee. International organizations (official or unofficial) that maintain contact with ISO can also participate in the relevant work. ISO maintains a close cooperative relationship with the International Electrotechnical Commission (IEC) in the field of electrotechnical standardization. The draft international standards formally adopted by the technical committee are submitted to the member bodies for voting. International standards can only be officially published if they are approved by at least 75% of the member bodies that participate in the voting. International Standard ISO 6507-2 was prepared by Technical Committee SC3\Hardness testing, Subcommittee 3, ISO/TC 164 “Mechanical testing of metals”.
This standard (second edition of ISO 6507-2) replaces ISO 146:1984 and ISO 146-2:1993 and is amended as follows: Two different international standards for hardness test (ISO 146:1984 and ISO 146-2:1993) have been merged into this part of ISO 6507.
A new table (Table 3) has been added on the estimated capability and maximum permissible error of measuring devices. — The values ​​of hardness tester repeatability in Table 4 have been modified. — A new chapter 6 has been added on two test cycles. — A new Appendix A “Examples of indirect test methods for measuring devices” (using standard indentations) has been added. 1. Newly added Appendix B "Precautions for diamond indenter" ISO6507 is under the general title "Vickers hardness test for metallic materials" and consists of the following three parts: - Part 1: Test method; - Part 2: Verification of hardness testers; - Part 3: Calibration of standard hardness blocks. Appendices A and B of this part of ISO6507 are for reference only. 1 Scope
National Standard of the People's Republic of China
Metallic Vickers hardness test-Part 2: Verification of hardness testersGB/T 4340. 2
idt ISO 6507-2:1997
Replaces GB/T 7661---1987
GB/T 17198---1997
This standard specifies the verification method of Vickers hardness testers used for determining Vickers hardness according to GB/T4340.1. This standard describes the direct verification method for verifying the basic functions of the hardness tester and the indirect verification method suitable for comprehensive verification of the hardness tester. The indirect verification method can be used independently for regular routine inspection of the hardness tester in use. If the hardness tester can also be used for hardness tests of other methods, the hardness tester must be verified separately according to each method. Portable hardness testers shall meet all the requirements of this standard, but the term "reinstall" in 6.1a) shall not apply to such hardness testers. The force values ​​in this standard are converted from dry gram-force (kgf) values. These force values ​​were quoted before the adoption of the International System of Units (SI). The benefits of citing integer values ​​of test force (integer Newton values) in SI units and the consequences for the relevant hardness scales will be considered and studied during the next revision of the international standard. At that time, this standard will also be revised accordingly as the international standard changes. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards GB/T4340.1-1999 Metal Vickers hardness test Part 1: Test method (eqvISO6507-1:1997) GB/T4340.3-1999 Metal Vickers hardness test Part 3: Calibration of standard hardness blocks (idtISO6507-3:1997) GB/T7997-1987 Cemented carbide Vickers hardness test method (eqvISO3878:1983) GB/T136341992 Standard force measuring instrument for testing machine inspection Sensor type standard force measuring instrument
(neq IS0 376:1987)
3 General requirements
Before testing the Vickers hardness tester, it should be checked to ensure that: a) the hardness tester is correctly installed;
b) the indenter spindle can slide in its guide body; c) the indenter handle is firmly installed in the spindle hole; d) the application and removal of the test force are free of shock or vibration and do not affect the reading; e) if the measuring device is integral with the hardness tester, then: 1) the switching from the removal of the test force to the measurement state does not affect the reading; 2) the lighting does not affect the reading;
3) when necessary, the center of the indentation should be located in the center of the field of view. The lighting device of the measuring microscope should illuminate the entire field of view evenly and should produce the maximum contrast between the indentation and the surrounding surface. Approved by the State Administration of Quality and Technical Supervision on October 10, 1999 382
2000-03-01 implementation
4 Direct inspection
GB/T 4340.2—1999
Direct inspection should be carried out within the temperature range of (23±5)°C. If the inspection is carried out outside this temperature range, it should be recorded in the inspection report.
The instruments used for inspection should have traceability to the legal measurement units of the People's Republic of China. Direct inspection includes:
a) inspection of test force;
b) inspection of indenter;
c) inspection of measuring device;
d) inspection of test force holding time.
4.1 Inspection of test force
4.1.1 Each test force used within the working range of the hardness tester should be measured. Whenever appropriate, the above force measurements should be made at at least three positions of the spindle at equal intervals throughout the entire range of movement of the spindle during the test. 4.1.2 The test force shall be measured by one of the following two methods: a) using a 0.2 grade standard dynamometer in accordance with GB/T13634-1992; b) balancing a force applied by a standard mass and mechanically amplified to an accuracy of ±0.2%. 4.1.3 Three readings shall be taken for each test force at each spindle position. The direction of movement of the spindle immediately before each reading shall be consistent with the direction of movement during the test.
4.1.4 Each measurement of the force shall be within the tolerance of the nominal test force given in Table 1. Table 1
Test force range F
F≥1.961
0. 098 07≤F1.961
4.2 Inspection of the indenter
4.2.1 The four faces of the diamond regular tetrahedron shall be polished and free of surface defects.
4.2.2 The shape of the indenter can be checked by direct measurement or by measuring the projection of the indenter on a projection screen. 4.2.3 The angle between the two opposite faces of the diamond pyramid top should be 136°±0.5° (see Figure 1). 136°±0.5°
Figure 1 Cone angle of diamond pyramid
4.2.4 The angle between the axis of the diamond pyramid and the axis of the indenter handle (perpendicular to the mounting surface) should be less than 0.5°. The four faces should intersect at -- points; the maximum allowable length of the intersection between the opposite faces is given in Table 2 (see Figure 2). Regardless of the period of direct inspection of the hardness tester, the inspection period of the indenter should not exceed two years. For precautions on diamond indenters, see Appendix B (Instructions).
Test force rangebzxz.net
F≥49.03
1.961≤F<19.03
0.09807≤F1.961
4.3 Inspection of measuring device
GB/T 4340. 2 --- 1999
Length of intersection
Figure 2 Schematic diagram of the intersection of the indenter cone
Maximum allowable length of the intersection
4.3.1 The required estimation capability of the measuring device depends on the size of the minimum indentation to be measured. The graduation of the measuring device scale and the estimation capability of the indentation diagonal shall comply with the provisions of Table 3 Table 3
Length of diagonal
Estimated capability of measuring device
0.000 2mm
Maximum allowable error
±0.000 1 mml
The estimated capability of the indentation measuring device for Vickers hardness test of cemented carbide materials is specified in GB/T7997. 4.3.2 The measuring device shall be inspected by measuring at least five intervals in each working range using a standard scale. The maximum permissible error of the measuring device shall comply with the provisions of Table 3. 4.3.3 In addition to the above direct inspection, the measuring device may also be inspected indirectly according to the procedure described in Appendix A (Suggested Appendix). 4.4 Inspection of test force holding time
The test force holding time shall comply with the provisions of GB/T4340.1. The permissible error of the hardness tester time control device is ±1s. Indirect inspection
Indirect inspection should be carried out in the temperature range of (23±5)°C using a standard hardness block calibrated according to GB/T4340.3. If the inspection is carried out outside this temperature range, it shall be recorded in the inspection report. Adoption instructions;
1 There is no "±" sign in ISO6507-2. The "±" sign in this column is added by this standard. 2] This article is different from the article in ISO6507-2 in terms of editing. The title of this article in ISO6507-2 is: "Test cycle time verification. Through the study of the corresponding article in ISO6507-1, it is believed that the essence of this article is to verify the accuracy of the test force holding time. For Vickers hardness tester, it is to verify the error of the hardness tester time control device. Therefore, this standard has made editorial changes to this article. 381
GB/T 4340. 2 -- 1999
5.1 When the hardness tester to be tested uses several test forces, at least two forces should be selected for testing. One of the forces should be the most commonly used test force of the hardness tester. For each selected test force, two standard blocks of different hardness should be selected from the different hardness ranges specified below. The selection of force and block should be appropriate, and at least one standard block in each hardness range should be used for testing. ≤225HV
400HV-~600HV
>700 HV
5.2 When the hardness tester to be tested uses only one test force, three standard blocks should be used for testing and one block should be selected for each hardness range specified in 5.1.
5:3 For special cases, the hardness tester can be tested at only one hardness value, and the tested hardness value should be approximately equal to the hardness value to be tested.
5.4 Five indentations should be pressed and measured on each standard block. The test should be carried out in accordance with GB/T4340.1. 5.5 The arithmetic mean values ​​of the lengths of the two diagonals of each indentation measured on each standard block, di, d2, d, are arranged in increasing order from small to large.
5.6 Under the specified test conditions, the repeatability error of the hardness tester's indication is determined by the following difference: ds - d,
The repeatability error of the hardness tester to be tested must meet the requirements of Table 4. Table 4
Maximum allowable value of repeatability error of hardness tester Hardness of standard block
|HV5 ~HV100HV0. 2-~≤HV5
>225HV
)ad+d++d.
HV5~HV100
Hardness of standard block
Under the specified test conditions, the indication error of the hardness tester is determined by the following difference: 5.7
Wherein, i-H++H.++H
H,.Hz,.,H,hardness value corresponding to di,d2,d.;H-hardness value calibrated by the standard hardness block used. HV
HV0.2~~HV5
Hardness of standard block
The maximum indication error of the hardness tester expressed as a percentage of the hardness value calibrated by the standard hardness block shall comply with the provisions of Table 5. HV
GB/T 4340.2-1999
Maximum permissible value of indication error of hardness tester
Hardness, HV
1When the diagonal length of the indentation is less than 0.020mm, the value is not given in the table2For intermediate values, the maximum permissible error can be obtained by interpolation. 450500
000t500
3The values ​​of microhardness tester in the table are given with a maximum permissible error of 0.001mm or 2% of the average value of the diagonal length of the indentation, whichever is greater.
6 Inspection cycle
6.1 Direct inspection
Direct inspection shall be carried out in the following cases:
a) When the hardness tester is installed or after disassembly and reassembly or reinstallation; b) When the indirect inspection result is unqualified;
c) When the indirect inspection time exceeds one year.
After each direct inspection, an indirect inspection shall be carried out. 6.2 Indirect test
The interval between two indirect tests depends on the maintenance level and the number of times the hardness tester is used. In any case, the interval should not exceed · year. 386
Test report
The test report should contain the following contents:
a) Indicate the adoption of this part of GB/T4340:
GB/T4340.2—1999
Note: For hardness testers that have passed the test of this standard, the number and name of this standard can be indicated on the product or product packaging or product manual. b) Test method (direct and/or indirect test); c) Identification information of the hardness tester (usually the content on the nameplate of the hardness tester, such as: hardness tester model, name, manufacturing date, number and manufacturer name, etc.)\3:
d) Test equipment (standard block, standard dynamometer, etc.); e) Test force;
f) Test temperature;
g) Test results;
h) Test date and testing agency.
Adoption instructions:
1This note is added for this standard, and there is no such content in the international standard ISO6507-2. 2]The content in brackets is added for this standard to clarify this content. 387
GB/T 4340. 2 - 1999
Appendix A
(Indicative Appendix)
Example of indirect verification of measuring devices
The measuring device can be verified indirectly by measuring the standard indentation on each standard block used for indirect verification of the hardness tester according to 5.1 (see the note to 8.3 of GB/T 4340.3-1999). The error of the measuring device, expressed as a percentage of the given length of the average diagonal of each standard indentation, should not exceed 1%. Appendix B
(Indicative Appendix)
Precautions for diamond indenters
Experience shows that many indenters that were initially good may deteriorate after a short period of use. This is due to cracks, dents or other defects on their surface. If such defects are discovered in time, many indenters can be repaired by re-grinding. Otherwise, any small defect on their surface will quickly deteriorate and make the indenter scrapped. Therefore: - When using the hardness tester every day, it is advisable to monitor the integrity of the indenter by visually checking the shape of the indentation on the standard block; - When the indenter is defective, the inspection of the indenter is no longer valid; - The indenter that has been reground or repaired by other methods should be re-inspected.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.