1、Designation: A 867 03 (Reapproved 2008)Standard 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 numb
2、er 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
3、 as 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
4、-Fe 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
5、 as 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
6、 in 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 metallu
7、rgymaterials 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 cons
8、idered standard.2. Referenced Documents2.1 ASTM Standards:2A 34/A 34M Practice for Sampling and Procurement Test-ing of Magnetic MaterialsA 341/A 341M Test Method for Direct Current MagneticProperties of Materials Using D-C Permeameters and theBallistic Test MethodsA 596/A 596M Test Method for Direc
9、t-Current MagneticProperties of Materials Using the Ballistic Method andRing SpecimensA 773/A 773M Test Method for dc Magnetic Properties ofMaterials Using Ring and Permeameter Procedures withdc Electronic Hysteresigraphs2.2 International Electrotechnical Commission Standard:3IEC 60404-7 Magnetic ma
10、terials. Part 7: Method of mea-surement 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 ty
11、pe,3.1.2 Dimensions 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 ana
12、lysis or magnetic 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 sui
13、tableproduct for 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, 2008. Published June 2008. Originallyapp
14、roved in 1986. Last previous edition approved in 2003 as A 86703.2For 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 webs
15、ite.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.9 Exceptions to this specification or special requ
16、ire-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 the producer.5.
17、 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. Available forms
18、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, centerlessground (all steel typ
19、es), 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 to hardness or mil
20、lannealed. 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 coils or straightene
21、d 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 specimenbefore measu
22、rement 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 10Cfor4hinawethydrogen atmosph
23、ere (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 Magnetic Testing:6.3.1
24、 Either ring or permeameter techniques may be used.For ring specimens either Test Methods A 596/A 596M orA 773/A 773M is permitted. For straight-length specimens,either Test Methods A 341/A 341M or A 773/A 773M is per-mitted.6.3.2 Whenever possible, test specimen size and shape shallconform to Pract
25、ice A 34/A 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
26、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 ofIEC 60404-7.6.4.2 RequirementsThe coerciv
27、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
28、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
29、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
30、Silicon 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 Strength (
31、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 maxA 867 03 (2008)2APPENDIXES(Nonmandatory Information)X1. TYPICAL PHYSICAL, MECHANICAL, AND MAGNETIC PROPERTIESX1.1 Typical physical, magnetic, and hardness properties ofthe f
32、ive 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.TABLE 3 DC Coercive Field Strength (Hc) Requirements(Coercimeter Testing)Types 1 and 1F Types 2 and 2F Type 3Oe 1.2 max 1.1 m
33、ax 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 (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
34、 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 induction (kG) 8.50 8.6
35、0 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 A 596/A 596M. Permeameter test results for maximumpermeability and residual induction are significantly lower as a result of unavoidable loop shearing effects. Coerci
36、ve 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 higher hardness than
37、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 HRBA 867 03 (2008)3X2. HEAT TREATMENT OF IRON-SILICON RELAY STEELSX2.1 Heat treatment of parts made from iron-silicon relaysteels is necessa
38、ry 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-treat
39、ing 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. Most com-monly, heat treatment is conducted at temperatures of approxi-mately 840C for a minimum of 2
40、h followed by slow cooling.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 impr
41、ovement in magnetic characteristics isachievable 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
42、part, produced from any type, is to beplated 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.A
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46、e on Standards, 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).A 867 03 (2008)4
