1、Designation: B848 10Standard Specification forPowder Forged (PF) Ferrous Materials1This standard is issued under the fixed designation B848; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in par
2、entheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers powder forged ferrous materi-als fabricated by hot densification of atomized prealloyed oriron powders and intended for u
3、se as structural parts.1.2 This specification covers powder forged parts madefrom the following materials:1.2.1 Compositions:1.2.1.1 PF-10XX Carbon Steel (produced from atomizediron powder and graphite powder),1.2.1.2 PF-10CXX Copper-Carbon Steel (produced fromatomized iron powder, copper and graphi
4、te powders),1.2.1.3 PF-11XX Carbon Steel with manganese sulfide forenhanced machinability (produced from atomized iron powder,manganese sulfide, and graphite powders),1.2.1.4 PF-11CXX Copper-Carbon Steel with manganesesulfide for enhanced machinability (produced from atomizediron powder, copper, man
5、ganese sulfide, and graphite pow-ders),1.2.1.5 PF-42XX Nickel-Molybdenum Steel (producedfrom prealloyed atomized iron-nickel-molybdenum powderand graphite powder),1.2.1.6 PF-46XX Nickel-Molybdenum Steel (producedfrom prealloyed atomized iron-nickel-molybdenum powderand graphite powder),1.2.1.7 PF-44
6、XX Molybdenum Steel (produced from preal-loyed atomized iron-molybdenum powder and graphite pow-der), and1.2.1.8 PF-49XX Molybdenum Steel (produced from preal-loyed atomized iron-molybdenum powder and graphite pow-der).NOTE 1Alloy composition designations are modifications of theAISI-SAE nomenclatur
7、e. For example: 10CXX designates a plain carbonsteel containing copper and XX amount of carbon. Compositional limitsof alloy and impurity elements may be different from theAISI-SAE limits.Chemical composition limits are specified in Section 6.NOTE 2XX designates the forged carbon content, in hundred
8、ths of apercent, that is specified by the purchaser for the application. For a givenspecified carbon content, the permissible limits shall be as specified in 6.2.NOTE 3The old acronym for powder forging P/F has been replaced byPF throughout the document. The change in the prefix for the materialdesi
9、gnations is just to match the currently approved acronym for powderforging. No change has been made to the material specification andperformance characteristics for the various powder forged materials.1.2.2 Grades:1.2.2.1 Grade ADensity equivalent to a maximum of0.5 % porosity. The minimum density o
10、f those sections of thepowder forged part so designated by the applicable partdrawing shall not be less than the value specified in Table 1.1.2.2.2 Grade BDensity equivalent to a maximum of1.5 % porosity. The minimum density of those sections of thepowder forged part so designated by the applicable
11、partdrawing shall not be less than the value specified in Table 1.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combi
12、ningvalues from the two systems may result in non-conformancewith the standard.2. Referenced Documents2.1 ASTM Standards:2A255 Test Methods for Determining Hardenability of SteelB243 Terminology of Powder MetallurgyB311 Test Method for Density of Powder Metallurgy (PM)Materials Containing Less Than
13、Two Percent PorosityB795 Test Method for Determining the Percentage of Al-loyed or Unalloyed Iron Contamination Present in PowderForged (PF) Steel MaterialsB796 Test Method for Nonmetallic Inclusion Content ofPowders Intended for Powder Forging (PF) ApplicationsB797 Test Method for Surface Finger Ox
14、ide PenetrationDepth and Presence of Interparticle Oxide Networks inPowder Forged (P/F) Steel PartsB934 Test Method for Effective Case Depth of FerrousPowder Metallurgy (P/M) Parts Using MicroindentationHardness MeasurementsE3 Guide for Preparation of Metallographic SpecimensE8 Test Methods for Tens
15、ion Testing of Metallic Materials1This specification is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.11 on Near Full Density Powder Metallurgy Materials.Current edition approved Dec. 1, 2010. Published Ma
16、rch 2011. Originallyapproved in 1994. Last previous edition approved in 2005 as B848 05. DOI:10.1520/B0848-10.2For 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 st
17、andards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.E18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE23 Test
18、Methods for Notched Bar Impact Testing ofMetallic MaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE350 Test Methods for Chemical Analysis of Carbon Steel,Low-Alloy Steel, Silicon Electrical Steel, Ingot Iron, andWrought IronE415 Test Method
19、for Atomic Emission Vacuum Spectro-metric Analysis of Carbon and Low-Alloy SteelE562 Test Method for Determining Volume Fraction bySystematic Manual Point CountE1019 Test Methods for Determination of Carbon, Sulfur,Nitrogen, and Oxygen in Steel, Iron, Nickel, and CobaltAlloys by Various Combustion a
20、nd Fusion TechniquesE1077 Test Methods for Estimating the Depth of Decarbur-ization of Steel Specimens2.2 MPIF Standard:3MPIF 35 Materials Standards for PF Steel Parts3. Terminology3.1 DefinitionsDefinitions of powder metallurgy termscan be found in Terminology B243. Additional descriptiveinformatio
21、n is available in the Related Material Section of Vol.02.05 of the Annual Book of ASTM Standards.3.2 Descriptions of Terms Specific to This Standard:3.2.1 core regiona core region is one where there is eitherno decarburization as determined by the procedure in 9.3.4 orthere is no hardened surface as
22、 determined by the procedure inS2.2.3.2.2 critical regiona critical region of a part is one thatrequires a density level or a microstructural characteristic to beseparately specified.4. Ordering Information4.1 Orders for parts conforming to this specification shallinclude the following:4.1.1 Alloy c
23、omposition, including carbon content (see1.2.1, Section 6, and Table 2),4.1.2 Grade (minimum density requirementsee 1.2.2 andSection 7),4.1.3 Heat treatment condition and hardness (see 8.1.3,8.1.4, and 8.2.3),4.1.4 Location of critical regions (see 3.2.2),3Available from Metal Powder Industries Fede
24、ration, 105 College Road East,Princeton, NJ 085406692.TABLE 1 Minimum Density for Selected Powder Forged SteelCompositions (Fully Annealed Heat Treatment ConditionFerrite/Pearlite Microstructure)A,BChemical CompositionDensity (g/cm3)Grade A(0.5 % porosity)CGrade B(1.5 % porosity)CPF-1040 7.81 7.74PF
25、-1060 7.81 7.73PF-10C40 7.81D7.74DPF-10C60 7.81D7.73DPF-1140 7.79 7.71PF-1160 7.78 7.70PF-11C40 7.79D7.71DPF-11C60 7.79D7.71DPF-4220 7.82 7.74PF-4240 7.81 7.73PF-4260 7.80 7.72PF-4420 7.82 7.74PF-4440 7.81 7.73PF-4460 7.81 7.73PF-4620 7.82 7.74PF-4640 7.81 7.73PF-4660 7.81 7.73PF-4680 7.80 7.72PF-49
26、20 7.83 7.75PF-4940 7.82 7.74PF-4960 7.81 7.74AQuench-hardening and tempering will reduce the density values. Normalizedsamples may have lower density values then fully annealed materials.BFor the purpose of determining conformance with this specification, measuredvalues shall be rounded “to the nea
27、rest unit” in the last right-hand digit used inexpressing the specification limit, in accordance with the rounding-off method ofPractice E29.CBased on the method described in Smith, D. W., “Calculation of the Pore-FreeDensity of PM Steels: Role of Microstructure and Composition,” The InternationalJo
28、urnal of Powder Metallurgy, Vol 28, No. 3, 1992, p. 259. Calculations based on350 ppm max oxygen content and all oxygen combined as 3MnO Al2O3 3SiO2.DThe method described by Smith is not considered applicable to steels withadmixed copper additions. Pore-free densities for these materials were deter-
29、mined by experiment.TABLE 2 Chemical Composition Requirements for PowderForged Parts (Weight %)AElement PF-10XX PF-10CXX PF-11XX PF-11CXXNickel, max 0.10 0.10 0.10 0.10Molybdenum,max0.05 0.05 0.05 0.05Manganese 0.100.25 0.100.25 0.300.60B0.300.60BCopper 0.30 max 1.82.2 0.30 max 1.82.2Chromium,max0.1
30、0 0.10 0.10 0.10Sulfur, max 0.025 0.025 0.23B0.23BSilicon, max 0.03 0.03 0.03 0.03Phosphorus,max0.03 0.03 0.03 0.03CarbonCCCCOxygenDDDDTotal Iron BalanceEBalanceEBalanceEBalanceEElement PF-42XX PF-46XX PF-44XX PF-49XXNickel 0.400.50 1.752.00 0.10 max 0.10 maxMolybdenum 0.550.65 0.500.60 0.800.95 1.4
31、1.6Manganese 0.200.35 0.100.25 0.080.18 0.080.18Copper, max 0.15 0.15 0.15 0.15Chromium,max0.10 0.10 0.10 0.10Sulfur, max 0.03 0.03 0.03 0.03Silicon, max 0.03 0.03 0.03 0.03Phosphorus,max0.03 0.03 0.03 0.03CarbonCCCCOxygenDDDDTotal Iron BalanceEBalanceEBalanceEBalanceEAFor the purpose of determining
32、 conformance with this specification, measuredvalues shall be rounded “to the nearest unit” in the last right-hand digit used inexpressing the specification limit, in accordance with the rounding-off method ofPractice E29.BCovers manganese sulfide (MnS) additions of from 0.3 to 0.5 %. Themanganese c
33、ontent in solution is similar to PF-10XX or PF-10CXX, that is, 0.10 to0.25 %.CCarbon content shall be as specified by the purchaser.DWhen required, maximum oxygen content shall conform to the amountspecified by purchaser. See S1.EFor information only. Quantitative determination of this element is no
34、t required.B848 1024.1.5 Whether functional or mechanical property testing isrequired, what type of testing is required, and what perfor-mance level is required (see 8.1.1, 8.1.2, 8.2.1, and 8.2.2),4.1.6 Whether the purchaser desires that his representativeinspect or witness the inspection and testi
35、ng of the materialprior to shipment (see 11.1 and 11.2),4.1.7 Whether there are special microstructural require-ments (see Section 9 and S4),4.1.8 Whether certification of the material is required (seeSection 13),4.1.9 Whether there is a maximum forged-oxygen content(see S1),4.1.10 Whether case hard
36、ening is required (see S2),4.1.11 Whether there is a maximum area percent porosityrequirement for critical regions (see 3.2.2 and S3), and4.1.12 ASTM designation and year of issue.5. Materials and Manufacture5.1 Make the structural parts by hot forging of powdermetallurgy (PM) preforms in confined d
37、ies with or withoutsubsequent heat treatment. Prepare PM preforms by pressing orby pressing and sintering material conforming to the designa-tions in 1.2.1 and meeting the chemical compositions specifiedin Section 6 and Table 2.6. Chemical Composition6.1 The hot forged material shall conform to the
38、require-ments prescribed in Table 2.6.2 Unless otherwise specified, the hot forged carbon con-tent shall not deviate from that specified by the purchaser bymore than 60.05 weight percent.6.3 Determine the concentration of the elements copper,chromium, manganese, molybdenum, nickel, phosphorus, andsi
39、licon in accordance with Test Method E415 or Test MethodE350; X-ray fluorescence (XRF) or inductively coupledplasma, atomic emission spectrometry (ICP-AES) techniquesmay also be used for these analyses. Determine the concentra-tion of the elements carbon and sulfur in accordance with TestMethods E10
40、19.7. Density Requirement7.1 The minimum density of those sections of powderforged parts so designated by the applicable part drawing shallnot be less than the values specified in Table 1.7.2 Determine the density of complete parts or sections ofparts in accordance with Test Method B311.8. Mechanica
41、l Property Requirements8.1 Mechanical Properties:8.1.1 The preferred method for verifying the acceptableperformance of a finished part is for the manufacturer and thepurchaser to agree upon a qualification test to be performed onan actual part. The specific test should be determined followingconside
42、ration of the function of the part. An example would bemeasuring the force needed to break teeth off a gear, using aprescribed test fixture.8.1.2 Where the part configuration permits, standard me-chanical property test specimens may be machined from thepart in the condition in which it is to be used
43、. (Remove testspecimens from parts to be used in the quenched and temperedcondition after heat treatment of the part to ensure themicrostructure is representative of the actual part.) The appli-cable part drawing or purchase order shall designate thelocation from which the mechanical property test s
44、pecimensare to be removed and the type of specimen to be tested.8.1.3 The core hardness range of parts shall be in accor-dance with the applicable part drawing or purchase order.8.1.4 The surface hardness range of parts shall be inaccordance with the applicable part drawing or purchase order.8.1.5 T
45、ypical mechanical properties of Grade A materialscovered by this specification are shown in Appendix X1.8.2 Mechanical Property Test Methods:8.2.1 Tensile Test MethodWhen requested, take tensiletest specimens from parts in accordance with the applicablepart drawing or purchase order. Test tensile sp
46、ecimens inaccordance with Test Methods E8. Determine yield strength bythe 0.2 % offset method.8.2.2 Impact Energy Test MethodWhen requested, takeCharpy V-notch impact test bars from parts in accordance withthe applicable part drawing or purchase order. Test impact barsin accordance with Test Methods
47、 E23; at room temperature, or,at a temperature agreed between the manufacturer and pur-chaser.8.2.3 Hardness Test MethodDetermine hardness measure-ments in accordance with Test Methods E18. Make corehardness measurements on sectioned parts within the coreregion of the part. Determine surface hardnes
48、s measurementsin accordance with the applicable part drawing on the originalforged surface, or, if machined, on the machined part surface.9. Microstructure Requirements9.1 Surface Finger Oxide Penetration:9.1.1 The maximum depth of penetration of surface fingeroxides from the finished part surface,
49、for each designatedcritical region of a powder forged part, shall not exceed thatagreed upon between the manufacturer and purchaser. Desig-nate critical regions by the applicable part drawing or purchaseorder.9.1.2 Determine the surface finger oxide penetration inaccordance with Test Method B797.9.2 Interparticle Oxide Networks:9.2.1 The extent of any interparticle oxide networks in eachdesignated critical region of a powder forged part shall notexceed that agreed upon between the manufacturer and pur-chaser. Designate critical regions on the applica
