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1、 Reference number ISO 2639:2002(E) ISO 2002 INTERNATIONAL STANDARD ISO 2639 Third edition 2002-11-01 Steels Determination and verification of the depth of carburized and hardened cases Acier Dtermination et vrification de la profondeur de cmentation Copyright International Organization for Standardi
2、zation Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:2002(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with
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5、care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2002 All rights reserved. Unless otherwise specified, no part of this publication
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7、l. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.ch Web www.iso.ch Printed in Switzerland ii ISO 2002 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24
8、/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:2002(E) ISO 2002 All rights reserved iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of prepari
9、ng 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 lia
10、ison 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 3. The main task of
11、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
12、drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 2639 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 7, Methods of testing
13、 (other than mechanical tests and chemical analysis). This third edition cancels and replaces the second edition (ISO 2639:1982), which has been technically revised. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/99
14、72545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MD
15、TNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 2639:2002(E) ISO 2002 All rights reserved 1 Steels Determination and verification of the depth of carburized and hardened cases 1 Scope This International Standard defines the case-hardened depth, and
16、specifies methods for the determination of this depth, in steel. It is applicable to a) carburized cases and carbonitrided cases; b) parts that, when heat treated to final hardness, have a hardness of less than 450 HV 1 at a distance of three times the case-hardened depth, from the surface. The case
17、-hardened depth is defined by special agreement where these conditions are not met. For steels that, in the part under test, and at a distance of three times the case-hardened depth from the surface, present a hardness greater than 450 HV 1, the criterion can still be used, provided that a limiting
18、hardness value greater than 550 HV 1 in steps of 25 units be selected for the case-hardened depth. 2 Normative references The following normative documents contain provisions, which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequen
19、t amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the lat
20、est edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 4545, Metallic materials Hardness test Knoop test ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test method 3 Term and definition For th
21、e purposes of this International Standard, the following term and definition applies. 3.1 case-hardened depth (of a carburized and hardened case) perpendicular distance between the surface and the layer having a hardness of 550 HV 1 in accordance with ISO 6507-1 or equivalent Knoop hardness in accor
22、dance with ISO 4545 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:2002(E) 2 ISO 2002
23、 All rights reserved 4 Conventions 4.1 Designation The case-hardened depth is designated by the letters CHD and is expressed in millimetres, e.g.: CHD = 0,8 mm. 4.2 Special cases 4.2.1 Vickers hardness measurements By agreement between the parties concerned, Vickers hardness measurements within the
24、range of HV 0,5 (4,9 N) to HV 1 (9,8 N) may be used. By agreement between the parties concerned limiting hardness values other than 550 HV 1 may be used. The use of another load or another limiting hardness shall be shown after the letters CHD, e.g.: CHD 515 HV 5. 4.2.2 Knoop hardness measurement By
25、 agreement between the parties concerned, measurement of the Knoop hardness may be used. 5 Determination of case-hardened depth 5.1 General The following method for the determination of the case-hardened depth is the only one applicable in the event of a dispute. 5.2 Principle The case-hardened dept
26、h is determined from the gradient of hardness on a cross-section normal to the surface. It is derived graphically from a curve representing the variation in hardness as a function of the distance from the surface of a part. 5.3 Procedure 5.3.1 Test specimen The measurement shall be made, unless othe
27、rwise specially agreed, on a cross-section of a part in a specified condition. 5.3.2 Preparation of the surface to be examined Polish the surface on which measurement is to be made so as to permit correct measurement of the size of the hardness impressions. Take all precautions to avoid rounding the
28、 edges of the surface and overheating the part. 5.3.3 Determination of hardness Make hardness impressions along one or more parallel lines normal to the surface and within a band of width, W, 1,5 mm (see Figure 1). Copyright International Organization for Standardization Provided by IHS under licens
29、e with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:2002(E) ISO 2002 All rights reserved 3 Figure 1 Position of hardness impressions The distance, S, separating two adjacent i
30、mpressions shall be not less than 2,5 times their diagonal (see Figure 1). The difference between the successive distances of each impression from the surface (e.g. a2 a1) shall not exceed 0,1 mm and the cumulative distances from the surface shall be measured to an accuracy of 25 m. The diagonals of
31、 the impression shall be measured to an accuracy of 0,5 m. Make impressions using a load of HV 0,1 (0,98 N) to HV 1 (9,8 N) or Knoop impressions under appropriate conditions and carry out their measurement using an optical device (camera system) giving a minimum magnification of 400 unless otherwise
32、 agreed between the parties concerned. Make the measurements on the prepared surface in two or more bands, the location of which shall be agreed between the parties concerned and for each band, plot the results in order to obtain the curve representing the variations in hardness as a function of dis
33、tance from the surface. 5.4 Expression of results From the two curves plotted, determine, for each band of the surface in question, the distance from the surface of the part at which the hardness is equal to 550 HV or equivalent Knoop hardness; such a distance represents the case-hardened depth of t
34、he band. If the difference between these two values is less than or equal to 0,1 mm, take the mean of these two distances as the case-hardened depth; if the difference between these two values is greater than 0,1 mm, repeat the test. 6 Verification of case-hardened depth If the thickness of the carb
35、urized case is specified, the following interpolation method may be used as a method of verification of the case-hardened depth. This is possible because the hardness gradient may be approximately represented by a straight line in that transitional area where the case-hardened depth, as defined in t
36、his International Standard, would end. Make at least five impressions on a normal cross-section of the part under test, at each of the distances d1 and d2 from the surface, distance d1 and d2 being respectively below and above the value for the specified case-hardened depth (see Figure 2). The value
37、 of d2 d1 shall not exceed 0,3 mm. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:200
38、2(E) 4 ISO 2002 All rights reserved Figure 2 Position of hardness measurement points The case-hardened depth is given by the formula 211s 1 12 ()() CHD ddHH d HH =+ where Hs is the specified hardness; 12 ,HH are the arithmetic means of the hardness values measured at distances d1 and d2 (see Figure
39、3). Figure 3 Mathematical verification of the case-hardened depth NOTE When using the interpolation method, it is good practice to check the hardness immediately below the surface. If there is excessive retained austenite in the subsurface case, the hardness in this area may be below the critical le
40、vel of 550 HV. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:2002(E) ISO 2002 All ri
41、ghts reserved 5 7 Test report The test report shall contain the following information: a) the part tested and the heat treatment to which it has been subjected; b) the area of the part in which the tests were carried out; c) the determined case-hardened depth. Copyright International Organization fo
42、r Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 2639:2002(E) ICS 77.040.99 Price based on 5 pages ISO 2002 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 20:51:25 MDTNo reproduction or networking permitted without license from IHS -,-,-