1、Designation: A867 03 (Reapproved 2013)Standard Specification forIron-Silicon Relay Steels1This standard is issued under the fixed designation A867; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、 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 wrought iron-silicon (Fe-Si)steels that are generally used in the manufacture of electrome-chanical devices, such a
3、s relays and solenoids, 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-F
4、e free machining2 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 a
5、s used in thisspecification 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 i
6、n the form of forgingbillets, 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 metallurg
7、ymaterials capable of being processed into magnetic corecomponents having similar silicon contents.1.6 The values stated in inch-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 consid
8、ered standard.2. Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling and Procurement Testingof Magnetic MaterialsA341/A341M Test Method for Direct Current MagneticProperties of Materials Using D-C Permeameters and theBallistic Test MethodsA596/A596M Test Method for Direct-Current
9、MagneticProperties of Materials Using the Ballistic Method andRing SpecimensA773/A773M Test Method for dc Magnetic Properties ofMaterials Using Ring and Permeameter Procedures withdc Electronic Hysteresigraphs2.2 International Electrotechnical Commission Standard:3IEC 60404-7 Magnetic materials. Par
10、t 7: Method ofmeasurement of the coercivity of magnetic materials in anopen magnetic circuit3. 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 Dimen
11、sions and tolerances. The tolerances are to bemutually agreed upon 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 magne
12、tic prop-erty evaluation, or both,3.1.7 Marking and packaging,3.1.8 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 f
13、or the consumers fabrication practice, and1This 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, 2013. Published July 2013. Originally approvedin 1986.
14、 Last previous edition approved in 2008 as A86703 (2008). DOI:10.1520/A0867-03R13.2For 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 pag
15、e onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.9 Exceptions to this specification
16、 or special require-ments.4. Chemical Composition4.1 The chemical composition requirements are shown inTable 1. Since magnetic and, possibly, mechanical propertiesare of primary importance, variations in composition fromthose shown in Table 1 are permitted by mutual agreementbetween the consumer and
17、 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 product.
18、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, centerless grou
19、nd(all steel types), cold drawn (all grades up to 0.500 in. (12.7mm) 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 to
20、 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 coil
21、s 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 spec
22、imenbefore 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 10Cfor4hinawet
23、hydrogen 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 Magnet
24、ic Testing:6.3.1 Either ring or permeameter techniques may be used.For ring specimens either Test Methods A596/A596M orA773/A773M is permitted. For straight-length specimens,either Test Methods A341/A341M or A773/A773M is permit-ted.6.3.2 Whenever possible, test specimen size and shape shallconform
25、to Practice A34/A34M. 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
26、(1.00 T).6.4 Coercimeter 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 IEC60404-7.6.4.2 RequirementsThe c
27、oercive 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 beid
28、entified 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 s
29、o designated 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
30、.50maxSilicon 1.10nom1.10nom2.30nom2.30nom4.00nomPhosphorus 0.05max0.10/0.220.05max0.10/0.250.05maxSulfur 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 Stre
31、ngth (Hc) Requirements(Conventional Testing)Types 1 and 1F Types 2 and 2F Type 3Oe 0.80 max 0.75 max 0.70 maxA/m 64 max 60 max 56 maxA867 03 (2013)2APPENDIXES(Nonmandatory Information)X1. TYPICAL PHYSICAL, MECHANICAL, AND MAGNETIC PROPERTIESX1.1 Typical physical, magnetic, and hardness properties of
32、the five types of 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.X2. HEAT TREATMENT OF IRON-SILICON RELAY STEELSX2.1 Heat treatment of parts made from iron-silicon relaysteels is necess
33、ary to obtain the best magnetic performance.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-trea
34、ting temperature is increased. SteelTypes 1 and 1F will show a decline in magnetic performancewhen heat treated above 870C as a result of austenitizationand subsequent grain refinement upon cooling. MostTABLE 3 DC Coercive Field Strength (Hc) Requirements(Coercimeter Testing)Types 1 and 1F Types 2 a
35、nd 2F Type 3Oe 1.2 max 1.1 max 1.0 maxA/m 96 max 88 max 80 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 (-cm) 25 40 58(-m) 0.25 1060.40 1060.58 106Saturation flux density (kG) 21.0 20.6 20.0(T)
36、 2.10 2.06 2.00Curie temperature (C) 761 748 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 ind
37、uction (kG) 8.50 8.60 7.00(T) 0.850 0.860 0.700AResults from ring specimens heat treated in accordance with 6.2 and tested in accordance with Test Method A596/A596M. Permeameter test results for maximumpermeability and residual induction are significantly lower as a result of unavoidable loop sheari
38、ng effects. Coercive field strength and residual induction are determinedfrom a maximum magnetic flux density of 10 000 G (1.00 T).TABLE X1.3 Typical Annealed Rockwell HardnessNOTE 1Bar hardness determined at mid radius.NOTE 2Bar and strip that are straightened and cut to length exhibit slightly hig
39、her hardness than shown in this table.Type 1 Type 1F Types 2 and2FType 3Mill annealed 60 HRB 75 HRB 90 HRB 100 HRBAs heat treated for magnetic properties 50 HRB 70 HRB 88 HRB 95 HRBA867 03 (2013)3commonly, heat treatment is conducted at temperatures ofapproximately 840C for a minimum of 2 h followed
40、 by slowcooling.X2.2 A protective 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
41、magnetic characteristics isachievable by using a higher dew-point (20 to 5C) hydrogenor forming gas atmosphere to promote decarburization.However, the high dew-point atmospheres should not be used(1) at temperatures in excess of 950C, (2) when heat treatingsteel Type 3, or (3) when the part, produce
42、d from any type, isto be plated after heat treatment.X2.4 Iron-silicon relay steels are very prone to rusting underordinary atmospheric conditions. A protective coating shouldbe applied to heat-treated parts as soon as possible. Chromium,nickel, or cadmium plating is most commonly used.ASTM Internat
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46、ds, 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 multiple 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A867 03 (2013)4
