ASTM_A_904_-_14.pdf

Designation:A90414Standard Specification for50 Nickel-50 Iron Powder Metallurgy Soft Magnetic Parts1This standard is issued under the fixed designation A904;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 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 the magnetic properties of 50nickel-50 iron parts fabricated by powder metallurgy tech-niques and is intended for parts that require high magneticpermeability,high electrical resistivity,low coercive fieldstrength,and low hysteresis loss.It differs from the wroughtalloy specification(see Specification A753)because these partsare porous.A number of magnetic properties such as perme-ability are proportional to the sintered density.1.2 This specification deals with powder metallurgy parts inthe sintered or annealed condition.Should the sintered parts besubjected to any secondary operation that causes mechanicalstrain,such as machining or sizing,they should be resintered orannealed.1.3 The values stated in customary(cgs-emu and inch-pound)units are to be regarded separately as standard.Thevalues given in parentheses are mathematical conversions to SIunits,which are provided for information only and are notconsidered standard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling and Procurement Testingof Magnetic MaterialsA340 Terminology of Symbols and Definitions Relating toMagnetic TestingA596/A596M Test Method for Direct-Current MagneticProperties of Materials Using the Ballistic Method andRing SpecimensA753 Specification for Wrought Nickel-Iron Soft MagneticAlloys(UNS K94490,K94840,N14076,N14080)A773/A773M Test Method for dc Magnetic Properties ofMaterials Using Ring and Permeameter Procedures withdc Electronic HysteresigraphsB328 Test Method for Density,Oil Content,and Intercon-nected Porosity of Sintered Metal Structural Parts andOil-Impregnated Bearings(Withdrawn 2009)3B962 Test Methods for Density of Compacted or SinteredPowder Metallurgy(PM)Products Using ArchimedesPrincipleE1019 Test Methods for Determination of Carbon,Sulfur,Nitrogen,and Oxygen in Steel,Iron,Nickel,and CobaltAlloys by Various Combustion and Fusion Techniques3.Terminology3.1 The terms and symbols used in this specification aredefined in Terminology A340.4.Ordering Information4.1 Orders for parts conforming to this specification shallinclude the following information.4.1.1 Reference to this standard 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 andso indicated on the applicable part drawing.The location of thecritical section is by mutual agreement between the user andproducer(see 6.2).4.1.5 Magnetic property requirements if they are other thanstated in 7.5.4.1.6 Certification of chemical composition or magneticproperty evaluation,or both(Sections 5 and 7).4.1.7 Marking and packaging requirements(Section 12).4.1.8 Exceptions to this specification or special require-ments such as functional testing as mutually agreed upon bythe producer and user.5.Chemical Composition5.1 The chemical composition of the parts shall conform tothe requirements prescribed in Table 1.1This 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 1,2014.Published May 2014.Originallyapproved in 1990.Last previous edition approved in 2009 as A90409.DOI:10.1520/A0904-14.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.2 Determination of metallic constituents shall be by amethod acceptable to both producer and user.Analysis ofcarbon,nitrogen,sulfur,and oxygen shall be done in accor-dance with Test Methods E1019.6.Sintered Density Requirements6.1 Magnetic and residual induction of powder metallurgyparts strongly depend on density.The density of powdermetallurgy parts is determined by the compressibility of thepowder,the compacting pressure,and sintering practice(temperature,time,and atmosphere).6.2 Parts produced in conformance with this specificationshall have a minimum si