1、Designation: A 867 03Standard Specification forIron-Silicon Relay Steels1This standard is issued under the fixed designation A 867; 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
2、indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers wrought iron-silicon (Fe-Si)steels that are generally used in the manufacture of electrome-chanical devices, such as relays and so
3、lenoids, requiring higherelectrical resistivity, higher permeability, and lower coercivityand residual magnetism than provided by either carbon steelsor soft magnetic low-carbon irons. The steels covered in thisspecification are:Steel Type Nominal Composition1 1.1 % Si-Fe1F 1.1 % Si-Fe free machinin
4、g2 2.3 % Si-Fe2F 2.3 % Si-Fe free machining3 4.0 % Si-Fe1.2 This specification covers steels in the form and condi-tion required for fabrication into parts. The fabricated partstypically require a final heat treatment to obtain the desiredmagnetic performance. The term mill annealed as used in thiss
5、pecification applies to a heat treatment, typically applied bythe producer, intended to improve formability. The mill annealdoes not provide the optimum magnetic performance and is notintended to replace the need for the finish annealing of parts.1.3 This specification covers steels in the form of f
6、orgingbillets, hot-rolled bar and strip, cold-finished bar, wire, andcold-rolled strip in thicknesses up to 0.250 in. (6.35 mm).1.4 This specification does not cover electrical sheet steelsused in transformer and motor laminations.1.5 This specification does not cover powder metallurgymaterials capa
7、ble of being processed into magnetic corecomponents having similar silicon contents.1.6 The values stated in customary (cgs-emu and inch-pound) units are to be regarded as standard. The values givenin parentheses are mathematical conversions to SI units whichare provided for information only and are
8、 not consideredstandard.2. Referenced Documents2.1 ASTM Standards:A 34/A 34M Practice for Sampling and Procurement ofMagnetic Materials2A 341 Test Method for Direct-Current Magnetic Propertiesof Materials Using dc Permeameters and the Ballistic TestMethods2A 596 Test Method for Direct-Current Magnet
9、ic Propertiesof Materials Using the Ballistic Method and Ring Speci-mens2A 773 Test Method for dc Magnetic Properties of MaterialsUsing Ring and Permeameter Procedures with dc Elec-tronic Hysteresigraphs22.2 Other:IEC Publication 404-7 Methods of Measurement of theCoercivity of Magnetic Materials in
10、 an Open MagneticCircuit33. Ordering Information3.1 Orders to this specification shall include as much of thefollowing information as is required to describe the desiredsteel:3.1.1 ASTM Specification number and steel type,3.1.2 Dimensions and tolerances. The tolerances are to bemutually agreed upon
11、between the consumer and the producer,3.1.3 Quantity (weight or number of pieces),3.1.4 Form and condition,3.1.5 Magnetic property requirements if they are otherwisethan stated herein,3.1.6 Certification of chemical analysis or magnetic prop-erty evaluation, or both,3.1.7 Marking and packaging,3.1.8
12、 End UseWhenever possible the consumer shouldspecify whether the product will be machined, blanked into flatpieces, blanked and formed, or deep drawn to shape. Thisinformation will help the producer provide the most suitableproduct for the consumers fabrication practice, and3.1.9 Exceptions to this
13、specification or special require-ments.4. Chemical Composition4.1 The chemical composition requirements are shown inTable 1. Since magnetic and, possibly, mechanical properties1This specification is under the jurisdiction of ASTM Committee A06 onMagnetic Properties and is the direct responsibility o
14、f Subcommittee A06.02 onMaterial Specifications.Current edition approved May 10, 2003. Published June 2003. Originallyapproved in 1986. Last previous edition approved in 1998 as A 867/A 867M 94(1998)e1.2Annual Book of ASTM Standards, Vol 03.04.3Available from American National Standards Institute (A
15、NSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.are of primary importance, variations in composition fromthose shown in Table 1 are permitted by mutual agreementbetween the consumer
16、and the producer.5. Form and Condition5.1 As the silicon content increases, cold working becomesmore difficult, hence, not all product forms are available ineach type of steel. The desired form and condition should bespecified and discussed with the producer to assure receivingthe appropriate produc
17、t. Available forms and conditions are:5.1.1 Forging Billet (all steel types)Billet surface ground,grit blasted, or acid cleaned.5.1.2 Hot-Rolled Product (all steel types)Hot rolled, hotrolled and acid cleaned, and hot-rolled and mechanicallycleaned.5.1.3 Cold-Finished BarsMill annealed, centerlessgr
18、ound (all steel types), cold drawn (all grades up to 0.500 in.(12.7 mm) round), cold-processed shapes such as squares,rectangles, hexagons (all types except Type 3), centerlessground, and machine turned.5.1.4 Strip (all types except Type 3)As-supplied conditionmust be specified as either cold rolled
19、 to hardness or millannealed. Steel can be supplied in coil form or as straightenedand cut to length flat product. Product can be supplied havinga rolled edge, either round or flat, or an edge produced byslitting.5.1.5 Wire (all types except Type 3)Cold drawn, colddrawn and mill annealed in either c
20、oils or straightened and cutto length.6. Magnetic Property Requirements6.1 Under this specification, only the coercive field strength(Hc) is required to be measured. This measurement can be doneeither using ring or permeameter methods or by use of acoercimeter. Since coercimeters saturate the test s
21、pecimenbefore measurement of the coercive field strength, two differ-ent sets of requirements are necessary, one for ring andpermeameter testing and one for coercimeter testing.6.2 Test Specimen Heat TreatmentThe test specimen shallbe heat treated before testing as follows; heat at 845 6 10Cfor4hina
22、wethydrogen atmosphere (dew point of 20 to5C) then cool at a rate of 50 to 100C/h to a temperature lessthan 540C followed by further cooling at any convenient rate.For heat treatment of Type 3 steels, dry hydrogen (dew pointless than 40C) shall be used instead of wet hydrogen.6.3 Conventional dc Mag
23、netic Testing:6.3.1 Either ring or permeameter techniques may be used.For ring specimens either Test Methods A 596 or A 773 ispermitted. For straight-length specimens, either Test MethodsA 341 or A 773 is permitted.6.3.2 Whenever possible, test specimen size and shape shallconform to Practice A 34/A
24、 34M. The densities of these steelsfor testing purposes are listed in Table X1.1.6.3.3 RequirementsThe coercive force requirements ofspecimens heat treated in accordance with 6.2 are shown inTable 2. The coercive field strength shall be measured from amaximum flux density of 10.0 kG (1.00 T).6.4 Coe
25、rcimeter Testing:6.4.1 Coercimeters are permitted provided it is demon-strated that flux density in the test specimen reaches at least 15kG (1.5 T) during the magnetization cycle and that the testmethod and test equipment satisfy the requirements of IECPublication 404-7.6.4.2 RequirementsThe coerciv
26、e field strength require-ments of specimens heat treated in accordance with 6.2 andtested using a coercimeter are shown in Table 3.7. Packaging and Marking7.1 Packaging shall be subject to agreement between theconsumer and the producer.7.2 Material furnished under this specification shall beidentifi
27、ed by the name or symbol of the producer, by alloy type,melt number, and material size. Each producer lot applied to aorder must be identified and packaged separately.8. Investigation of Claim8.1 Where any order fails to meet the requirements of thisspecification, disposition of the material so desi
28、gnated shall besubject to agreement between the consumer and the producer.9. Keywords9.1 coercive field strength; iron-silicon steel; relay steelTABLE 1 Chemical Composition RequirementsType1Type1FType2Type2FType3Carbon 0.04max0.04max0.04max0.04max0.04maxManganese 0.50max0.50max0.50max0.50max0.50max
29、Silicon 1.10nom1.10nom2.30nom2.30nom4.00nomPhosphorus 0.05max0.10/0.22 0.05max0.10/0.25 0.05maxSulfur 0.04max0.04max0.04max0.04max0.04maxAluminum 0.35max0.35max0.50max0.50max0.50maxIronAbalance balance balance balance balanceAIron is not analyzed nor is it reported.TABLE 2 DC Coercive Field Strength
30、 (Hc) Requirements(Conventional Testing)Types 1 and 1F Types 2 and 2F Type 3OeA/m0.80 max64 max0.75 max60 max0.70 max56 maxA867032APPENDIXES(Nonmandatory Information)X1. TYPICAL PHYSICAL, MECHANICAL, AND MAGNETIC PROPERTIESX1.1 Typical physical, magnetic, and hardness properties ofthe five types of
31、steel are listed in Table X1.1, Table X1.2, andTable X1.3, respectively. The data provided are for informationonly and are not requirements in this specification.TABLE 3 DC Coercive Field Strength (Hc) Requirements(Coercimeter Testing)Types 1 and 1F Types 2 and 2F Type 3OeA/m1.2 max96 max1.1 max88 m
32、ax1.0 max80 maxTABLE X1.1 Typical Physical PropertiesTypes 1 and 1F Types 2 and 2F Type 3Density (g/cm3) 7.75 7.65 7.60(kg/m3) 7750 7650 7600Electrical resistivity (V-cm) 25 40 58(V-m) 0.25 3 1060.40 3 1060.58 3 106Saturation flux density (kG) 21.0 20.6 20.0(T) 2.10 2.06 2.00Curie temperature (C) 76
33、1 748 728Mean coefficient of expansion from 25to 400C (106/C)12.8 13.2 13.5TABLE X1.2 Typical dc Magnetic PropertiesATypes 1 and 1F Types 2 and 2F Type 3Maximum permeability 14 800 11 200 9000Coercive field strength (Oe) 0.44 0.47 0.49(A/m) 35 37 39Residual induction (kG) 8.50 8.60 7.00(T) 0.850 0.8
34、60 0.700AResults from ring specimens heat treated in accordance with 6.2 and tested in accordance with Test Method A 596. Permeameter test results for maximum permeabilityand residual induction are significantly lower as a result of unavoidable loop shearing effects. Coercive field strength and resi
35、dual induction are determined from a maximummagnetic flux density of 10 000 G (1.00 T).TABLE X1.3 Typical Annealed Rockwell HardnessNOTE 1 Bar hardness determined at mid radius.NOTE 2Bar and strip that are straightened and cut to length exhibit slightly higher hardness than shown in this table.Type
36、1 Type 1F Types 2 and2FType 3Mill annealedAs heat treated formagnetic properties60 HRB50 HRB75 HRB70 HRB90 HRB88 HRB100 HRB95 HRBA867033X2. HEAT TREATMENT OF IRON-SILICON RELAY STEELSX2.1 Heat treatment of parts made from iron-silicon relaysteels is necessary to obtain the best magnetic performance.
37、Magnetic behavior improves (that is, permeability increasesand coercive field strength decreases) when heat treating isperformed at temperatures as low as 700C. For steel Types 2,2F, and 3, further improvement in magnetic performanceoccurs as the heat-treating temperature is increased. SteelTypes 1
38、and 1F will show a decline in magnetic performancewhen heat treated above 870C as a result of austenitizationand subsequent grain refinement upon cooling. Most com-monly, heat treatment is conducted at temperatures of approxi-mately 840C for a minimum of 2 h followed by slow cooling.X2.2 A protectiv
39、e nonoxidizing, noncarburizing, and non-nitriding atmosphere should be used. Low dew-point atmo-spheres such as hydrogen, forming gas (5 to 15 % hydrogen-nitrogen), and dissociated ammonia can be used. Vacuum heattreatment can also be used.X2.3 Further improvement in magnetic characteristics isachie
40、vable by using a higher dew-point (20 to 5C) hydrogenor forming gas atmosphere to promote decarburization. How-ever, the high dew-point atmospheres should not be used (1) attemperatures in excess of 950C, (2) when heat treating steelType 3, or (3) when the part, produced from any type, is to beplate
41、d after heat treatment.X2.4 Iron-silicon relay steels are very prone to rustingunder ordinary atmospheric conditions. A protective coatingshould be applied to heat-treated parts as soon as possible.Chromium, nickel, or cadmium plating is most commonlyused.ASTM International takes no position respect
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43、dard 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 Internatio
44、nal Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.
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