1、Designation: B848 15Standard 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, PF-1130CXX, and PF-1135CXXCopper-Carbon Steels with manganese sulfide for enhancedmachinability (produced from atom
5、ized iron powder, copper,manganese sulfide, and graphite powders),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 gra
6、phite powder),1.2.1.7 PF-44XX Molybdenum Steel (produced from preal-loyed atomized iron-molybdenum powder and graphitepowder), 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 o
7、f theAISI-SAE nomenclature. 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 c
8、arbon content, in hundredths 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 pr
9、efix for the materialdesignations 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 % porosi
10、ty. The minimum density of 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 desi
11、gnated by the applicable 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 independ
12、ently of the other. Combiningvalues 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)Materi
13、als Containing Less Than 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 ofFerrous Powders Intended for Powder Forging (PF) Ap-plicationsB797
14、 Test Method for Surface Finger-Oxide PenetrationDepth and Presence of Interparticle Oxide Networks inPowder Forged (PF) Steel PartsB934 Test Method for Effective Case Depth of FerrousPowder Metallurgy (PM) Parts Using MicroindentationHardness Measurements1This specification is under the jurisdictio
15、n 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 Nov. 1, 2015. Published December 2015. Originallyapproved in 1994. Last previous edition approved in 20
16、10 as B848 10. DOI:10.1520/B0848-15.2For 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 website.*A Summary of Changes sec
17、tion appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E3 Guide for Preparation of Metallographic SpecimensE8 Test Methods for Tension Testing of Metallic MaterialsE18 Test Methods for Rockwell Hardnes
18、s of Metallic Ma-terialsE23 Test Methods for Notched Bar Impact Testing of Me-tallic 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 Iro
19、n, andWrought IronE415 Test Method for Analysis of Carbon and Low-AlloySteel by Spark Atomic Emission SpectrometryE562 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 Co
20、baltAlloys by Various Combustion and 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
21、. Additional descriptiveinformation is available in the Related Material Section of Vol.02.05 of the Annual Book of ASTM Standards.3.2 Definitions 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
22、orthere is no hardened surface as 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 shallin
23、clude the following:4.1.1 Alloy composition, 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),4.1.5 Wheth
24、er 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 testing of the materialprior to shi
25、pment (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 hardening is required (see S2),4.1
26、.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 dies with or withoutsubsequent
27、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 2.3Available from Metal Powder Industries Federation, 105 College Road East,Princeton, NJ 085406692.TABL
28、E 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-1060 7.81 7.73PF-10C40 7.81D7.74DPF-10C60 7.81D7.73DPF-11
29、40 7.79 7.71PF-1160 7.78 7.70PF-11C40 7.79D7.71DPF-11C60 7.79D7.71DPF-1130C50 7.82D7.74DPF-1130C60 7.82D7.74DPF-1135C60 7.82D7.74DPF-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 7.72
30、PF-4920 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 th
31、e nearest 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 Internatio
32、nalJournal 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 d
33、eter-mined by experiment.B848 1526. Chemical Composition6.1 The hot forged material shall conform to the 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 Dete
34、rmine the concentration of the elements copper,chromium, manganese, molybdenum, nickel, phosphorus, andsilicon 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 an
35、alyses. Determine the concentra-tion of the elements carbon and sulfur in accordance with TestMethods E1019.7. 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 Det
36、ermine the density of complete parts or sections ofparts in accordance with Test Method B311.8. Mechanical Property Requirements8.1 Mechanical Properties:8.1.1 The preferred method for verifying the acceptableperformance of a finished part is for the producer and thepurchaser to agree upon a qualifi
37、cation test to be performed onan actual part. The specific test should be determined followingconsideration 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-cha
38、nical property test specimens may be machined from thepart in the condition in which it is to be used. (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
39、 part drawing or purchase order shall designate thelocation from which the mechanical property test specimensare 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 har
40、dness range of parts shall be inaccordance with the applicable part drawing or purchase order.TABLE 2 Chemical Composition Requirements for PowderForged Parts (Weight %)AElement PF-10XX PF-10CXX PF-11XX PF-11CXX PF-1130CXX PF-1135CXXNickel, max 0.10 0.10 0.10 0.10 0.10 0.10Molybdenum,max0.05 0.05 0.
41、05 0.05 0.05 0.05Manganese 0.100.25 0.100.25 0.300.60B0.300.60B0.300.60B0.300.60BCopper 0.30 max 1.82.2 0.30 max 1.82.2 2.73.3F3.03.8FChromium,max0.10 0.10 0.10 0.10 0.10 0.10Sulfur, max 0.025 0.025 0.23B0.23B0.23 0.23Silicon, max 0.03 0.03 0.03 0.03 0.03 0.03Phosphorus,max0.03 0.03 0.03 0.03 0.03 0
42、.03CarbonCCCCCCOxygenDDDDDDTotal 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 1.41.6Manganese 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.
43、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 conformance with this specification, measuredvalues shall be rounded “to the nearest unit” in the last righ
44、t-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 %. The manga-nese content in solution is similar to PF-10XX or PF-10CXX, that is, 0.10 to0.25 %.CCarbon content shall be as s
45、pecified by the purchaser.DWhen required, maximum oxygen content shall conform to the amount specifiedby purchaser. See S1.EFor information only. Quantitative determination of this element is not required.FSome of the copper may be prealloyed.B848 1538.1.5 Typical mechanical properties of Grade A ma
46、terialscovered 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 specimens inaccordance with Test Methods E8.
47、 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 E23; at room temperature, or,at a tempera
48、ture agreed between the producer and purchaser.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 hardness measurementsin accordance with the applicable
49、 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, for each designatedcritical region of a powder forged part, shall not exceed thatagreed upon between the producer and purchaser. Designatecritical regions by the applicable part drawing or purchaseorder.9.1.2 Determine the surface finger oxide penetration inaccordance with Test Method B797.9.2 In
