1、Designation: A 839 02 (Reapproved 2008)Standard Specification forIron-Phosphorus Powder Metallurgy (P/M) Parts for SoftMagnetic Applications1This standard is issued under the fixed designation A 839; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase 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-phosphorus powder metallurgy materials
3、. These parts are usedin magnetic applications requiring higher permeability andelectrical resistivity and lower coercive field strength thanattainable routinely from parts produced from iron powder.1.2 Two powder types are covered; Type I containingnominally 0.45 % phosphorus, and Type II containin
4、g nomi-nally 0.8 % phosphorus.1.3 This specification deals with P/M parts in the sintered orannealed condition. Should the sintered parts be subjected toany secondary operation that causes mechanical strain, such asmachining or sizing, they should be resintered or annealed.1.4 The values stated in i
5、nch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2. Referenced Documents2.1 ASTM Standards:2A 34/A 34M Practice for Sampling and Procurement Test-ing of Magneti
6、c MaterialsA 596/A 596M Test Method for Direct-Current MagneticProperties of Materials Using the Ballistic Method andRing SpecimensA 773/A 773M Test Method for dc Magnetic Properties ofMaterials Using Ring and Permeameter Procedures withdc Electronic HysteresigraphsB 328 Test Method for Density, Oil
7、 Content, and Intercon-nected Porosity of Sintered Metal Structural Parts andOil-Impregnated BearingsE 1019 Test Methods for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel and in Iron, Nickel, andCobalt Alloys3. Ordering Information3.1 Purchase orders for parts conforming to this spec
8、ifica-tion shall include the following information:3.1.1 Reference to this specification and year of issue/revision.3.1.2 The type of powder to be used (see 4.1 and Table 1).3.1.3 Reference to an applicable part drawing.3.1.4 Quantity required.3.1.5 A critical cross section of the part shall be defi
9、ned andso indicated on the applicable part drawing. The location of thecritical section is by mutual agreement between the user andthe producer (see 5.2).3.1.6 Magnetic property requirements if they are other thanstated in Table 2.3.1.7 Whether certification of chemical analysis or magneticproperty
10、evaluation is required (see Sections 4 and 6).3.1.8 Marking and packaging requirements (see Section 11).3.1.9 Whether testing for magnetic aging is required.3.1.10 Exceptions to this specification or special require-ments such as functional testing, as mutually agreed uponbetween the producer and th
11、e user.4. Chemical Composition4.1 The chemical composition of the parts shall conform tothe requirements prescribed in Table 1.4.2 Chemical analysis for phosphorus shall be determinedby wet chemistry in accordance with a method to be agreedupon between the user and the producer. Analysis of carbon,o
12、xygen, and nitrogen shall be done in accordance with TestMethods E 1019.5. Sintered Density Requirements5.1 Magnetic and residual induction of P/M parts stronglydepend on density. The density of P/M parts is determined bythe compressibility of the powder, the compacting pressure,and sintering practi
13、ce (temperature, time, and atmosphere).5.2 Parts produced in conformance with this specificationshall have a minimum sintered density of 6.8 g/cm3(6800kg/m3) in the critical section of the part. The critical sectionshall be defined by agreement between the user and theproducer.5.3 Sintered density s
14、hall be determined in accordance withTest Method B 328.1This specification is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility of Subcommittee A06.02 onMaterial Specifications.Current edition approved May 1, 2008. Published June 2008. Originallyappr
15、oved in 1985. Last previous edition approved in 2002 as A 83902.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM websi
16、te.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Magnetic Property Requirements6.1 Due to the nature of P/M parts production, magnetictesting of each lot is not required by this specification.However, it is strongly recommended
17、that the user require theproducer to conduct periodic magnetic evaluations and tocertify the results obtained. Such magnetic property evalua-tions shall be conducted in the following manner.6.2 When requested, each lot of parts should be sinteredwith at least one and preferably three ring test speci
18、mens whichcomply with the geometric requirements listed in PracticeA 34/A 34M. The ring specimen(s) shall be produced from thesame mixed lot of powder used to produce the parts.6.3 The dc magnetic properties shall be determined inaccordance with Test Methods A 596/A 596M or A 773/A 773M.6.4 For the
19、purpose of this specification, only the coercivefield strength determined from a maximum applied magneticfield strength of 15 Oe (1200 A/m) needs to be determined.Other magnetic properties may be specified by mutual agree-ment between the user and the producer.6.5 Coercive Field Strength Requirement
20、sThree grades,defined by coercive field strength, are stipulated by thisspecification and are listed in Table 2. The coercive fieldstrength requirements for Type I are based on interlaboratorystudy conducted by ASTM Committee B09. The requirementsfor Type II are based on both interlaboratory study a
21、ndtechnical literature.6.6 Magnetic AgingNitrogen introduced during sinteringcan cause time-dependent degradation of magnetic properties.Therefore, when requested by the user, the producer shall testfor aging. To determine the susceptibility of the parts to aging,the test ring(s) should be heated fo
22、r either 100 h at 150C or600 h at 100C and the coercive field strength remeasured. Achange in coercive field strength of 10 % or more of theoriginal value is evidence that aging has occurred.6.7 Since magnetic properties are strongly affected byprocess conditions, refer to the Appendix X1-Appendix X
23、3 fortypical values and explanatory notes.7. Workmanship, Finish and Appearance7.1 The parts shall be uniform in composition and uniformin density within critical sections.7.2 If parts are sectioned or fractured, there shall be noreadily recognizable defects.8. Sampling8.1 A lot shall consist of par
24、ts of the same form anddimensions, produced from a single mixed powder batch andfrom an unchanged process, without discontinuity in produc-tion, and submitted for inspection at one time.8.2 The user and the producer shall agree upon a represen-tative number of specimens for testing.9. Rejection and
25、Rehearing9.1 Parts that fail to conform to the requirements of thisspecification may be rejected. Rejection should be reported tothe producer or supplier promptly and in writing. In case ofdissatisfaction with the results of the test, the producer orsupplier may make claim for a rehearing.9.2 The di
26、sposition of rejected parts shall be subject toagreement between the user and the producer.10. Certification10.1 When specified in the purchase order or contract, theuser shall be furnished certification that samples representingeach lot have either been tested or inspected as directed in thisspecif
27、ication and the requirements have been met.10.2 When specified in the purchase order or contract, areport of the test results shall include:10.2.1 Chemical composition,10.2.2 Part density in the critical section,10.2.3 Magnetic test results, if required by the user, and10.2.4 The results of any othe
28、r tests stipulated in thepurchase order or contract.11. Packaging and Package Marking11.1 Packaging shall be subject to agreement between theuser and the producer.11.2 Parts furnished under this specification shall be in acontainer identified by the name or symbol of the partsproducer.12. Keywords12
29、.1 coercive field strength; iron-phosphorus; powder met-allurgy (P/M); P/M partsTABLE 1 Chemical Composition Requirements (in WeightPercent)Element Type I Type IIPhosphorus 0.40/0.50 0.75/0.85Carbon, max 0.03 0.03Oxygen, max 0.10 0.10Nitrogen, max 0.01 0.01IronAbalance balanceAIron is the balance by
30、 difference. Quantitative analysis of this element is notrequired.TABLE 2 Maximum Coercive Field Strength RequirementsGrade Powder Type I (0.45 % P) Powder Type II (0.8 % P)1 1.4 Oe (110 A/m) 1.2 Oe (96 A/m)2 1.8 Oe (140 A/m) 1.4 Oe (110 A/m)3 2.0 Oe (160 A/m) 1.7 Oe (140 A/m)A 839 02 (2008)2APPENDI
31、XES(Nonmandatory Information)X1. TYPICAL MAGNETIC AND MECHANICAL PROPERTIES SINTERED AT 1120C IN DISSOCIATED AMMONIAX1.1 The data provided in this appendix are for informationonly and are not requirements in this specification. Typicalmagnetic and mechanical properties are listed in Table X1.1and Ta
32、ble X1.2, respectively. The influence of sintered densityis shown in both tables. For Table X1.1, the maximum fluxdensity, residual induction, and coercive field strength aremeasured from a maximum applied magnetic field strength of15 Oe (1200 A/m).X2. TYPICAL MAGNETIC AND MECHANICAL PROPERTIES SINT
33、ERED AT 1120C IN DRY HYDROGENX2.1 The data provided in this appendix are for informationonly and are not requirements in this specification. Typicalmagnetic and mechanical properties are listed in Table X2.1and Table X2.2, respectively. The influence of sintered densityis shown in both tables. For T
34、able X2.1, the maximum fluxdensity, residual induction, and coercive field strength aremeasured from a maximum applied magnetic field strength of15 Oe (1200 A/m).TABLE X1.1 Typical Magnetic PropertiesType I Powder (0.45 % P) Type II Powder (0.8 % P)Sintered density, g/cm36.8 7.0 7.2 6.8 7.0 7.2(kg/m
35、3) 6 800 7 000 7 200 6 800 7 000 7 200(Relative) maximum permeability 2 300 2 600 2 700 3 500 4 000 4 500Maximum flux density, G 10 500 11 500 12 500 11 000 12 000 13 000(T) 1.05 1.15 1.25 1.10 1.20 1.30Residual induction, G 8 500 9 000 10 000 10 000 11 000 12 000(T) 0.85 0.90 1.00 1.00 1.10 1.20Coe
36、rcive field strength, Oe 1.7 1.7 1.7 1.5 1.5 1.5(A/m) 140 140 140 120 120 120TABLE X1.2 Typical Mechanical PropertiesType I Powder (0.45 % P) Type II Powder (0.8 % P)Sintered density, g/cm36.8 7.0 7.2 6.8 7.0 7.2(kg/m3) 6 800 7 000 7 200 6 800 7 000 7 2000.2 % Offset yield strength, psi 30 000 32 00
37、0 35 000 40 000 45 000 50 000(MPa) 210 220 240 280 310 340Ultimate tensile strength, psi 40 000 45 000 50 000 48 000 50 000 55 000(MPa) 280 310 340 330 340 380Elongation in 1 in. (25.4 mm), % 577233Apparent hardness, HRB 40 45 55 55 65 70TABLE X2.1 Typical Magnetic PropertiesType I Powder (0.45 % P)
38、 Type II Powder (0.8 % P)Sintered density, g/cm37.0 7.2 7.4 7.0 7.2 7.4(kg/m3) 7 000 7 200 7 400 7 000 7 200 7 400(Relative) maximum permeability 3 000 3 200 3 600 4 000 4 500 5 000Maximum flux density, G 11 500 12 500 13 000 12 000 13 000 13 500(T) 1.15 1.25 1.30 1.20 1.30 1.35Residual induction, G
39、 9 000 10 000 11 000 10 500 11 500 13 000(T) 1.00 1.00 1.10 1.05 1.15 1.30Coercive field strength, Oe 1.7 1.7 1.7 1.3 1.3 1.3(A/m) 140 140 140 100 100 100A 839 02 (2008)3X3. TYPICAL MAGNETIC AND MECHANICAL PROPERTIES SINTERED AT 1260C IN DRY HYDROGENX3.1 The data provided in this appendix are for in
40、formationonly and are not requirements in this specification. Typicalmagnetic and mechanical properties are listed in Table X3.1and Table X3.2, respectively. The influence of sintered densityis shown in both tables. For Table X3.1, the maximum fluxdensity, residual induction, and coercive field stre
41、ngth aremeasured from a maximum applied magnetic field strength of15 Oe (1200 A/m).ASTM 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
42、validity 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
43、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. If you feel that your comments h
44、ave not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multip
45、le copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE X2.2 Typical Mechanical PropertiesType I Powder (0.45 % P) Type II Powder (0.8 % P)Sintered
46、density, g/cm37.0 7.2 7.4 7.0 7.2 7.4(kg/m3) 7 000 7 200 7 400 7 000 7 200 7 4000.2 % Offset yield strength, psi 32 000 35 000 38 000 45 000 48 000 53 000(MPa) 220 240 260 310 330 360Ultimate tensile strength, psi 45 000 50 000 55 000 53 000 57 000 62 000(MPa) 310 340 380 360 390 430Elongation in 1
47、in. (25.4 mm), % 777444Apparent hardness, HRB 45 55 60 65 70 75TABLE X3.1 Typical Magnetic PropertiesType I Powder (0.45 % P) Type II Powder (0.8 % P)Sintered density, g/cm37.0 7.2 7.4 7.0 7.2 7.4(kg/m3) 7 000 7 200 7 400 7 000 7 200 7 400(Relative) maximum permeability 3 000 3 200 3 600 5 000 5 500
48、 6 000Maximum flux density, G 11 500 12 500 13 500 13 000 13 500 14 000(T) 1.15 1.25 1.35 1.30 1.35 1.40Residual induction, G 9 000 10 000 11 000 12 000 12 500 13 000(T) 0.9 1.00 1.10 1.20 1.25 1.30Coercive field strength, Oe 1.5 1.5 1.5 1.0 1.0 1.0(A/m) 120 120 120 80 80 80TABLE X3.2 Typical Mechan
49、ical PropertiesType I Powder (0.45 % P) Type II Powder (0.8 % P)Sintered density, g/cm37.0 7.2 7.4 7.0 7.2 7.4(kg/m3) 7 000 7 200 7 400 7 000 7 200 7 4000.2 % Offset yield strength, psi 32 000 39 000 41 000 45 000 48 000 53 000(MPa) 220 269 283 310 330 360Ultimate tensile strength, psi 45 000 55 000 60 000 50 000 55 000 58 000(MPa) 310 379 414 340 380 400Elongation in 1 in. (25.4 mm), % 10 12 15 2 2 2Apparent hardness, HRB 45 55 60 65 70 75A 839 02 (2008)4
