1、Designation: A811 03 (Reapproved 2008)A811 15Standard Specification forSoft Magnetic Iron Parts Fabricated by Powder Metallurgy(P/M) Techniques1This standard is issued under the fixed designation A811; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers parts produced from iron powder metallurgy materials.1.2 This
3、 specification deals with P/M powder metallurgy parts in the sintered or annealed condition. Should the sintered partsbe subjected to any secondary operation that causes mechanical strain, such as machining or sizing, they should be resintered orannealed.1.3 The values stated in customary (cgs-emu a
4、nd inch-pound) SI units are to be regarded as standard. The values given inparentheses are mathematical conversions to SI units customary (cgs-emu and inch-pound) units, which are provided forinformation only, and are not considered standard.1.4 This standard does not purport to address all of the s
5、afety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling a
6、nd Procurement Testing of Magnetic MaterialsA340 Terminology of Symbols and Definitions Relating to Magnetic TestingA596/A596M Test Method for Direct-Current Magnetic Properties of Materials Using the Ballistic Method and Ring SpecimensA773/A773M Test Method for Direct Current Magnetic Properties of
7、 Low Coercivity Magnetic Materials Using Hysteresig-raphsB328B962 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts andOil-Impregnated BearingsMethods for Density of Compacted or Sintered Powder Metallurgy (PM) Products UsingArchimedes Principle (Wi
8、thdrawn 2009)E1019 Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys byVarious Combustion and Fusion Techniques3. Terminology3.1 The terms and symbols used in this specification are defined in Terminology A340.4. Ordering Information4.1
9、Purchase orders for parts conforming to this specification shall include the following information:4.1.1 Reference to this specification and year of issue/revision,4.1.2 Reference to an applicable part drawing,4.1.3 Quantity required,4.1.4 A critical cross section of the part shall be defined and so
10、 indicated on the applicable part drawing. The location of thecritical section is by mutual agreement between the purchaseruser and the producer (6.2),4.1.5 Magnetic property requirements if they are other than stated in Table 1,1 This specification is under the jurisdiction of ASTM Committee A06 on
11、 Magnetic Properties and is the direct responsibility of Subcommittee A06.02 on MaterialSpecifications.Current edition approved Nov. 1, 2008April 1, 2015. Published December 2008April 2015. Originally approved in 1983. Last previous edition approved in 20032008 asA811 03.A811 03 (2008). DOI: 10.1520
12、/A0811-03R08.10.1520/A0811-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM st
13、andard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all ca
14、ses only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.6 Whether certification of chemical analysis or magnetic property evaluatio
15、n is required (Sections 5 and 7),4.1.7 Marking and packaging requirements (Section 12), and4.1.8 Exceptions to this specification or special requirements such as functional testing as mutually agreed upon between theproducer and the purchaser.user.5. Chemical Composition5.1 The chemical composition
16、of the parts shall conform to the requirements prescribed in Table 2.5.2 Determination of metallic constituents shall be by a method acceptable to both the producer and the purchaser.user.Analysisof carbon, oxygen, sulfur, and nitrogen shall be done in accordance with Test Methods E1019.6. Sintered
17、Density Requirements6.1 Magnetic and residual induction of P/M powder metallurgy parts strongly depend on density. The density of P/M powdermetallurgy parts is determined by the compressibility of the powder, the compacting pressure, and sintering practice (temperature,time, and atmosphere).6.2 Part
18、s produced in conformance with this specification shall have a minimum sintered density of 6.6 g/cmMg/m3 (6600kg/m3) in the critical section of the part. The critical section shall be defined by agreement between the purchaseruser and theproducer.6.3 Sintered density shall be determined in accordanc
19、e with Test Method B328B962.7. Magnetic Property Requirements7.1 Because of the nature of P/M powder metallurgy parts production, magnetic testing of each lot is not required by thisspecification. However,Nevertheless, it is strongly recommended that the purchaseruser require the producer to conduct
20、 periodicmagnetic evaluations and to certify such results. Such magnetic property evaluations shall be conducted in the following manner.7.2 When requested, each lot of parts should be sintered with at least one and preferably three ring test specimens which complywith the geometric requirements lis
21、ted in Practice A34/A34M. The ring specimen(s) shall be produced from the same mixed lotof powder used to produce the parts.7.3 The magnetic properties shall be determined in accordance with Test Methods A596/A596M or A773/A773M.7.4 For the purpose of this specification, only the coercive field stre
22、ngth determined from a maximum applied magnetic fieldstrength of 15 Oe (1200 A/m)1200 A/m (15 Oe) needs to be determined. Other magnetic properties may be specified by mutualagreement between the purchaser and the producer.TABLE 1 Maximum Coercive Field Strength RequirementsGrade Coercive Field Stre
23、ngth1 1.8 Oe (140 A/m)2 2.0 Oe (160 A/m)3 2.3 Oe (180 A/m)TABLE 1 Maximum Coercive Field Strength RequirementsGrade Coercive Field Strength1 140 A/m (1.8 Oe)2 160 A/m (2.0 Oe)3 180 A/m (2.3 Oe)TABLE 2 Chemical Requirements (weight percent)Element %Carbon, max 0.03Oxygen, max 0.10Nitrogen, max 0.01Ot
24、hersA 0.50, maxIronB balanceA Others refers to trace elements which are to be regarded as incidental and notdeliberate additions.B Iron is the balance by difference. Quantitative analysis of this element is notrequired.A811 1527.5 Coercive Field Strength Requirements RequirementsThree grades, define
25、d by coercive field strength, are stipulated bythis specification and are listed in Table 1. The coercive field strength requirement for Grade 3 was developed from aninterlaboratory study. The values for Grades 1 and 2 are based on a literature review and are believed to reflect the current industry
26、capabilities.7.6 Magnetic AgingNitrogen introduced during sintering can cause time-dependent degradation of magnetic properties.Therefore, when requested by the purchaser,user, the producer shall test for aging. To determine the susceptibility of the parts toaging, the test ring(s) should be heated
27、in air for either 100 h at 150 6 5C 5 C or 600 h at 100 6 5C 5 C and the coercivefield strength remeasured. A change in coercive field strength of 10 % or more of the original value is evidence that aging hasoccurred.7.7 Since magnetic properties are strongly affected by process conditions, refer to
28、 Appendix X1 for typical values andexplanatory notes.8. Workmanship, Finish, and Appearance8.1 The parts shall be uniform in composition and uniform in density within critical sections.8.2 If parts are sectioned or fractured, there shall be no readily recognizable defects.9. Sampling9.1 A lot shall
29、consist of parts of the same form and dimensions, produced from a single mixed powder batch and from anunchanged process, without discontinuity in production, and submitted for inspection at one time.9.2 The purchaseruser and producer shall agree upon a representative number of specimens for testing
30、.10. Rejection and Rehearing10.1 Parts that fail to conform to the requirements of this specification shall be rejected. Rejection should be reported to theproducer or supplier promptly and in writing. In case of dissatisfaction with the results of the test, the producer or supplier maymake claim fo
31、r a rehearing.10.2 The disposition of rejected parts shall be subject to agreement between the purchaseruser and the producer.11. Certification11.1 When specified in the purchase order or contract, the purchaseruser shall be furnished certification that samplesrepresenting each lot have either been
32、tested or inspected as directed in this specification and the requirements have been met.11.2 When specified in the purchase order or contract, a report of the test results shall include the following:11.2.1 Chemical composition,11.2.2 Part density in the critical section,11.2.3 Magnetic test result
33、s, if required by purchaser,user, and11.2.4 The results of any other tests stipulated in the purchase order or contract.12. Packaging and Package Marking12.1 Packaging shall be subject to agreement between the purchaseruser and the producer.12.2 Parts furnished under this specification shall be in a
34、 container identified by the name or symbol of the parts producer.13. Keywords13.1 coercive field strength; iron; P/M parts;powder metallurgy; powder metallurgy (P/M)partsA811 153APPENDIX(Nonmandatory Information)X1. TYPICAL MAGNETIC AND MECHANICAL PROPERTIESX1.1 Typical magnetic and mechanical prop
35、erties, based on interlaboratory studies, are listed in Table X1.1, Table X1.2, and TableX1.3. Table X1.1 contains properties typically achieved when sintering is conducted at 1120C 1120 C in dissociated ammonia.Table X1.2 contains properties typically achieved when sintering is conducted at 1120C 1
36、120 C in dry hydrogen or in a vacuum.Table X1.3 contains properties typically achieved when sintering is conducted at 1260C 1260 C in dry hydrogen or in a vacuum.The influence of sintered density is shown in all three tables. The data provided are for information only and are not requirementsin this
37、 specification.X1.2 Maximum flux density, residual induction, and coercive field strength are measured from a maximum applied magnetic fieldstrength of 15 Oe (1200 A/m).1200 A/m (15 Oe).TABLE X1.1 1120C Sinter in Dissociated AmmoniaSintered Density (g/cm3) (kg/m3) 6.66600 6.96900 7.27200(Relative) m
38、aximum permeability 1 700 2 100 2 700Maximum flux density (G) 9 000 10 500 12 000(T) 0.90 1.05 1.20Residual induction (G) 7 800 9 000 10 500(T) 0.78 0.90 1.05Coercive field strength (Oe) 2.1 2.1 2.1(A/m) 170 170 1700.2 % offset yield strength (psi) 11 000 17 000 22 500(MPa) 76 120 155Ultimate tensil
39、e strength (psi) 18 000 27 500 37 000(MPa) 120 190 260Percent elongation, 1 in. (25.4 mm) 6 11 16Apparent hardness (HRF) 40 50 55TABLE X1.1 1120 C Sinter in Dissociated AmmoniaSintered Density (Mg/m3) 6.6 6.9 7.2(Relative) maximum permeability 1 700 2 100 2 700Maximum flux density T 0.90 1.05 1.20(G
40、) 9 000 10 500 12 000Residual induction T 0.78 0.90 1.05(G) 7 800 9 000 10 500Coercive field strength A/m 170 170 170(Oe) 2.1 2.1 2.10.2 % offset yield strength MPa 75 120 155(psi) 11 000 17 000 22 500Ultimate tensile strength MPa 120 190 255(psi) 18 000 27 500 37 000Percent elongation, 25.4 mm 6 11
41、 16Apparent hardness (HRF) 40 50 55A811 154TABLE X1.2 1120C Sinter in Dry Hydrogen or VacuumSintered Density (g/cm3) (kg/m3) 6.66600 6.96900 7.27200(Relative) maximum permeability 1 800 2 300 2 900Maximum flux density (G) 9 500 10 500 12 000(T) 0.95 1.05 1.20Residual induction (G) 8 200 9 700 11 000
42、(T) 0.82 0.97 1.10Coercive field strength (Oe) 1.8 1.8 1.8(A/m) 140 140 1400.2 % offset yield strength (psi) 11 000 17 000 22 500(MPa) 76 120 155Ultimate tensile strength (psi) 19 000 28 000 37 500(MPa) 130 190 259Percent elongation in 1 in. (25.4 mm) 8 12 17Apparent hardness (HRF) 40 50 55TABLE X1.
43、2 1120 C Sinter in Dry Hydrogen or VacuumSintered Density (Mg/m3) 6.6 6.9 7.2(Relative) maximum permeability 1 800 2 300 2 900Maximum flux density T 0.95 1.05 1.20(G) 9 500 10 500 12 000Residual induction T 0.82 0.97 1.10(G) 8 200 9 700 11 000Coercive field strength A/m 140 140 140(Oe) 1.8 1.8 1.80.
44、2 % offset yield strength MPa 75 120 155(psi) 11 000 17 000 22 500Ultimate tensile strength MPa 130 190 260(psi) 19 000 28 000 37 500Percent elongation in 25.4 mm 8 12 17Apparent hardness (HRF) 40 50 55TABLE X1.3 1260C Sinter in Dry Hydrogen or VacuumSintered Density (g/cm3) (kg/m3) 6.66600 6.96900
45、7.27200(Relative) maximum permeability 2 800 3 300 3 800Maximum flux density (G) 10 000 11 500 13 000(T) 1.05 1.20 1.30Residual induction (G) 8 500 10 000 11 500(T) 0.85 1.0 1.15Coercive field strength (Oe) 1.6 1.6 1.6(A/m) 120 120 1200.2 % offset yield strength (psi) 10 000 16 000 21 000(MPa) 69 11
46、0 140Ultimate tensile strength (psi) 20 000 29 000 38 000(MPa) 140 200 260Percent elongation in 1 in. (25.4 mm) 10 15 20Apparent hardness (HRF) 38 45 50TABLE X1.3 1260 C Sinter in Dry Hydrogen or VacuumSintered Density (Mg/m3) 6.6 6.9 7.2(Relative) maximum permeability 2 800 3 300 3 800Maximum flux
47、density T 1.00 1.15 1.30(G) 10 000 11 500 13 000Residual induction T 0.85 1.00 1.15(G) 8 500 10 000 11 500Coercive field strength A/m 130 130 130(Oe) 1.6 1.6 1.60.2 % offset yield strength MPa 70 110 145(psi) 10 000 16 000 21 000Ultimate tensile strength MPa 140 200 260(psi) 20 000 29 000 38 000Perc
48、ent elongation in 25.4 mm 10 15 20Apparent hardness (HRF) 38 45 50A811 155ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity
49、of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend.
