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1、BRITISH STANDARD BS ISO 13947:2007 Metallic powders Test method for the determination of non-metallic inclusions in metal powders using a powder-forged specimen ICS 77.160 ? Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Co
2、py, (c) BSI BS ISO 13947:2007 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 March 2007 BSI 2007 ISBN 978 0 580 50331 3 National foreword This British Standard was published by BSI. It is the UK implementation of ISO 13947:2007. The UK pa
3、rticipation in its preparation was entrusted to Technical Committee ISE/65, Sintered metal components. A list of organizations represented on ISE/65 can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are respons
4、ible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. DateComments Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Co
5、py, (c) BSI INTERNATIONAL STANDARD ISO 13947 First edition 2007-02-15 Reference number ISO 13947:2007(E) Metallic powders Test method for the determination of non-metallic inclusions in metal powders using a powder-forged specimen Poudres mtalliques Dtermination de la teneur en inclusions non mtalli
6、ques dans les poudres mtalliques laide dune prouvette forge de poudre BS ISO 13947:2007 Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI ii Licensed Copy: London South Bank University, London South Bank Universi
7、ty, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI iii Contents Page 1Scope 1 2Normative references 1 3Principle 2 4Significance and use . 2 5Apparatus . 2 6Test piece . 3 7Procedure . 3 8Test report 4 9Precision and bias . 4 BS ISO 13947:2007 Licensed Copy: London South Bank Univers
8、ity, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally
9、 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 liaison with ISO, also take part in the w
10、ork. 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 2. The main task of technical committees is to prepare Int
11、ernational 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 drawn to the possibility that some of
12、the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 13947 was prepared by Technical Committee ISO/TC 119, Powder metallurgy, Subcommittee SC 2, Sampling and testing methods for powders (including powd
13、ers for hardmetals). BS ISO 13947:2007 Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 1 Metallic powders Test method for the determination of non-metallic inclusions in metal powders using a powder-forged spec
14、imen SAFETY PRECAUTIONS This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this International Standard to establish appropriate safety and health practices and to determine the applicability of regulatory lim
15、itations prior to use. 1Scope This International Standard specifies a metallographic method for determining the non-metallic inclusion level in metal powders using a powder-forged specimen. The test method covers repress powder-forged test specimens in which there has been minimal lateral flow (). T
16、he core region of the powder-forged test specimen contains no porosity detectable at magnification. This test method can also be used to determine the non-metallic inclusion content of powder-forged steel parts. However, in parts where there has been a significant amount of material flow, the near-n
17、eighbour separation distance needs to be changed, or the inclusion sizes agreed between the parties need to be adjusted. This test method is not suitable for determining the non-metallic inclusion level of parts that have been forged such that the core region contains porosity. At the magnification
18、used for this test method, residual porosity is hard to distinguish from inclusions. Too much residual porosity makes a meaningful assessment of the inclusion population impossible. This test method may be applied to materials that contain manganese sulfide (admixed or prealloyed), provided the near
19、-neighbour separation distance is changed from to . 2Normative references The 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
20、any amendments) applies. ISO/TR 14321:1997, Sintered metal materials, excluding hardmetals Metallographic preparation and examination ASTM B 796-02, Standard test method for nonmetallic inclusion content of powders intended for powder forging (P/F) applications ASTM E 3-01, Standard practice for pre
21、paration of metallographic specimens ASTM E 768-99, Standard practice for preparing and evaluating specimens for automatic inclusion assessment of steel 1 % 100 30m15m BS ISO 13947:2007 Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Unc
22、ontrolled Copy, (c) BSI 2 3Principle A section representing the core region of the test specimen (part) is cut from the test piece (part) prior to metallographic grinding and polishing (mounting the section is optional). The polished sample is examined microscopically at a magnification of and a not
23、e is made of inclusions greater than a predetermined size. The maximum Ferets diameter is used to determine inclusion size. A Ferets diameter is a caliper diameter, as illustrated in Figure 1. The fragmented nature of some inclusions means that their size determination is somewhat complicated. The c
24、oncept of near-neighbour separation shall be used in determining inclusion size. According to this concept, if an inclusion is within a certain distance of its neighbouring particles, it is considered as a member of an inclusion cluster or agglomerate. Detected features within of one another are con
25、sidered as part of the same inclusion. The concept is illustrated schematically in Figure 2. The non-metallic inclusion level of the test specimen (part) is reported as the number of inclusions, per , greater than or equal to the predetermined size. 4Significance and use 4.1The non-metallic inclusio
26、n level of ferrous powders is an indication of powder cleanliness. In pressed and sintered ferrous P/M materials, the extensive porosity present masks the effect of inclusions on mechanical properties. In contrast, the properties of a P/M material processed to near pore-free density are strongly inf
27、luenced by the composition, size, size distribution, and location of non-metallic inclusions. 4.2The test for non-metallic inclusions in fully dense steel parts is useful as a characteristic to classify or differentiate one grade of powder or batch of parts from another, and a lot-to-lot quality com
28、parison of powders intended for powder forging. 4.3A significant amount of variation in non-metallic inclusion content will occur if the powder used to form the test specimen (parts) does not meet the required quality standards for non-metallic inclusion content, or processing of the test specimen (
29、parts) has been carried out under conditions that do not permit oxide reduction or allow oxidation of the test specimen (part), or both. 4.4The use of the near-neighbour concept offers a more conservative estimate of the inclusions: it will overestimate rather than underestimate them. 5Apparatus 5.1
30、Equipment, for the metallographic preparation of test specimens. 5.2Metallographic microscope, permitting observation and measurement up to a magnification of 100 diameters using light with a wavelength of (green filter), an objective lens with a magnification of from 8 to , and a numerical aperture
31、 between 0,16 and 0,20. NOTEDefining the light optics used is important because this determines the features that will be resolved, and all detected features are included in the assessment of inclusion size. 100 30m 100 mm2 544 nm 12,5 BS ISO 13947:2007 Licensed Copy: London South Bank University, L
32、ondon South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 3 6Test piece 6.1For the evaluation of the non-metallic inclusion content of a powder that is intended for use in powder- forging applications, the powder shall be mixed with an appropriate amount of graphite
33、 and lubricant and compacted to a specified green density. The test method covers repress powder-forged test specimens in which there has been minimal lateral flow () so the diameter of the green compact shall be such, relative to the diameter of the forging die, that this requirement is met. 6.2A m
34、etallographic specimen shall be removed from the powder-forged test specimen (part), austenitized, and quenched. Hardening of the specimen facilitates sample preparation by preventing smearing of soft inclusions and scratching. 6.3The polished surface of the specimen (part) to be examined shall be n
35、ot less than in area. Multiple sections are permitted, in order to obtain the necessary area for measurement on small parts. 6.4The polished surface shall be parallel to the direction of working; that is, parallel to the direction of travel of the forging tools, and shall represent the core region o
36、f the test specimen (part). 7Procedure 7.1Preparation of specimens In polishing the specimens, it is highly important that a clean polish be obtained and that the inclusions not be pitted, dragged or obscured. It is therefore recommended that the procedures described in ASTM E 3 and E 768 be followe
37、d. Automated grinding and polishing procedures are recommended. Examine specimens in the as-polished condition, free of the effects of any prior etching (if used). ISO/TR 14321:1997 shall be followed. 7.2Measurement of non-metallic inclusion content 7.2.1Survey at least of the surface of the polishe
38、d specimen at a magnification of using light with a wavelength of (green filter), an objective lens with a magnification of from to and a numerical aperture between 0,16 and 0,20. 7.2.2Size the detected inclusions on the basis of near-neighbour separation. Features within () of one another (within o
39、f one another at magnification) are considered to be part of the same inclusion. 7.2.3For individual features less than in size, three such features within of one another are required to constitute an inclusion aggregate, when the near-neighbour separation principle is used. 7.2.4Add an individual f
40、eature less than in size to an inclusion larger than , provided both features are within of one another, when the near-neighbour separation principle is used. Examples are given in Figure 2. 7.2.5Measure and record the number of inclusion particles according to the principle of near-neighbour separa
41、tion and sized using the maximum Ferets diameter that are greater than or equal to in length, greater than or equal to in length, and greater than or equal to in length. In addition to the use of the near-neighbour separation concept to size the inclusions, the size of the individual particles can b
42、e measured. 1 % 350 mm2 350 mm2100 544 nm812,5 30m 0,03 mm3 mm100 30m30m 30m30m 30m 30m 100m 150m BS ISO 13947:2007 Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 4 7.2.6If the inclusions are also sized indivi
43、dually, the inclusions are sized using the maximum Ferets diameter as in 7.2.5. Results from the use of the near-neighbour separation concept will usually be more conservative (more larger inclusions). 8Test report The test report should include the following information: a)a reference to this Inter
44、national Standard; b)the number of non-metallic inclusions per that are greater than or equal to in length, greater than or equal to in length, or greater than or equal to in length; c)whether the particles were sized individually, in addition to using the near-neighbour separation principle; d)the
45、total area examined. 9Precision and bias 9.1The precision and bias that can be expected through the use of this test method is currently under review by ASTM Subcommittee B09.11 on near-full-dense P/M materials. Key 1Maximum Ferets diameter 2Ferets diameter Figure 1 Schematic illustration of Ferets
46、diameter 100 mm2 30m 100m 150m BS ISO 13947:2007 Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI 5 Key 1Maximum Ferets diameter Figure 2 Schematic illustration of the “near-neighbour” concept and maximum Ferets
47、 diameter BS ISO 13947:2007 Licensed Copy: London South Bank University, London South Bank University, Sat Mar 17 04:10:04 GMT+00:00 2007, Uncontrolled Copy, (c) BSI BS ISO 13947:2007 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body resp
48、onsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amen
49、dments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: +44 (0)20 8996 9000. Fax: +44 (0)20 8996 7400. BSI offers members an individual updating service called PLU