1、Designation: A876 12Standard Specification forFlat-Rolled, Grain-Oriented, Silicon-Iron, Electrical Steel,Fully Processed Types1This standard is issued under the fixed designation A876; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio
2、n, 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 detailed requirements towhich the specified grades of flat-rolled, grain-
3、oriented, fullyprocessed electrical steels shall conform. These steels are usedprimarily in transformer cores operating at moderate to highmagnetic flux densities at commercial power frequencies (50and 60 Hz).1.2 These grain-oriented electrical steels are low-carbon,silicon-iron alloys with a silico
4、n content of approximately3.2 % in which low core loss and high permeability in thedirection of rolling have been achieved by appropriate metal-lurgical processing.1.3 The electrical-steel grades described in this specificationinclude (1) conventional grain-oriented electrical steel tested at15 kG (
5、1.5 T) in accordance with Test Method A343/A343M,(2) conventional grain-oriented electrical steel tested at 17 kG(1.7 T) in accordance with Test Method A343/A343M,(3)high-permeability grain-oriented electrical steel tested at 17 kG(1.7 T) in accordance with Test Method A343/A343M, and (4)laser-scrib
6、ed high-permeability grain-oriented electrical steeltested at 17 kG (1.7 T) in accordance with Test MethodsA804/A804M.1.4 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 pr
7、ovided for information only and are not consideredstandard.2. Referenced Documents2.1 ASTM Standards:2A34/A34M Practice for Sampling and Procurement Testingof Magnetic MaterialsA340 Terminology of Symbols and Definitions Relating toMagnetic TestingA343/A343M Test Method for Alternating-Current Mag-n
8、etic Properties of Materials at Power Frequencies UsingWattmeter-Ammeter-Voltmeter Method and 25-cm Ep-stein Test FrameA345 Specification for Flat-Rolled Electrical Steels forMagnetic ApplicationsA664 Practice for Identification of Standard Electrical SteelGrades in ASTM SpecificationsA700 Practices
9、 for Packaging, Marking, and Loading Meth-ods for Steel Products for ShipmentA717/A717M Test Method for Surface Insulation Resistivityof Single-Strip SpecimensA719/A719M Test Method for Lamination Factor of Mag-netic MaterialsA721/A721M Test Method for Ductility of Oriented Electri-cal SteelA804/A80
10、4M Test Methods for Alternating-Current Mag-netic Properties of Materials at Power Frequencies UsingSheet-Type Test SpecimensA937/A937M Test Method for Determining InterlaminarResistance of Insulating Coatings Using Two AdjacentTest SurfacesA976 Classification of Insulating Coatings for ElectricalSt
11、eels by Composition, Relative Insulating Ability andApplication3. Terminology3.1 The terms and symbols used in this specification aredefined in Terminology A340.4. Classification4.1 The ASTM core-loss type designations, formulated inaccordance with Practice A664, for grain-oriented electricalsteels
12、covered by this specification are listed 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.This specification replaces A665, A725, and A843.Current edition approved No
13、v. 1, 2012. Published December 2012. Originallyapproved in 1987. Last previous edition approved in 2009 as A876091. DOI:10.1520/A0876-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume i
14、nformation, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15. Condition5.1 These grain-oriented electrical steels may be purchasedin any of the following conditions (whi
15、ch are combinations ofmaterial form and surface type or treatment) as desired for theexpected end use.5.1.1 Condition NFAn annealed coil form having aninorganic surface coating, Type C-2 (Note 1). This material isnot flattened and so exhibits appreciable coil curvature. Theprincipal application is i
16、n spirally wound or formed cores inwhich the strip curvature is not detrimental to fabricatingprocedures or device performance.5.1.2 Condition F2Thermally flattened sheet or coiledstrip having an inorganic surface coating, Type C-2, plus athinner (compared to Condition F5) inorganic coating, TypeC-5
17、, applied over the inherent C-2 coating. The principalapplication is in spirally wound or formed cores in which stripcurvature is not detrimental to fabricating procedures or deviceperformance.5.1.3 Condition F5Thermally flattened sheet or coiledstrip having an inorganic surface coating, Type C-2, p
18、lus aninorganic coating, Type C-5, applied over the inherent C-2coating to provide extra surface insulation resistance. Theprincipal application is in flat sheared laminations for cores ofpower transformers.5.1.4 Condition PQThermally flattened sheet or coiledstrip (sometimes called “punching qualit
19、y”) with the inherentC-2 coating removed and an inorganic coating, Type C-5,applied for insulative purposes. The principal application is inflat stamped laminations for small stacked cores with onlymoderate surface insulation requirements.NOTE 1Additional description of surface coating Types C-2 and
20、 C-5is presented in Specification A345 and Classification A976.5.2 Core-loss types having code letters Pand Q are availableonly in Condition F5.6. Ordering Information6.1 Orders for material under this specification shall includesuch of the following information as is required to describe themateria
21、l adequately:6.1.1 ASTM specification number,6.1.2 ASTM core-loss type designation (Table 1),6.1.3 Material condition (form and surface type) designa-tion (5.1),6.1.4 Ductility class (when required),6.1.5 Sheet or strip width,6.1.6 Length (only when cut lengths are specified),6.1.7 Total weight of e
22、ach ordered item,6.1.8 Limitations on lift weight,6.1.9 Limitations on coil size,6.1.10 End Use(Whenever practicable, the user shouldspecify whether the ordered material will be made into flatTABLE 1 Core-Loss Type DesignationsConventional Grain-Oriented Electrical SteelTested at 15 kG (1.5 T) in Ac
23、cordance with Test Method A343/A343MASTMCore-LossTypeAAimThickness,Bin. (mm)Maximum Specific CoreLoss,CW/lb (W/kg)60 Hz 50 Hz18G041 0.0070 (0.18) 0.41 (0.90) 0.31 (0.68)23G045 0.0090 (0.23) 0.45 (0.99) 0.34 (0.75)27G051 0.0106 (0.27) 0.51 (1.12) 0.39 (0.85)30G058 0.0118 (0.30) 0.58 (1.28) 0.44 (0.97
24、)35G066 0.0138 (0.35) 0.66 (1.46) 0.50 (1.11)Conventional Grain-Oriented Electrical SteelTested at 17 kG (1.7 T) in Accordance with Test Method A343/A343MASTMCore-LossTypeAAimThickness,Bin. (mm)Maximum Specific CoreLoss,CW/lb (W/kg)60 Hz 50 Hz23H070 0.0090 (0.23) 0.70 (1.54) 0.53 (1.17)27H074 0.0106
25、 (0.27) 0.74 (1.63) 0.56 (1.24)30H083 0.0118 (0.30) 0.83 (1.83) 0.63 (1.39)35H094 0.0138 (0.35) 0.94 (2.07) 0.71 (1.57)High-Permeability Grain-Oriented Electrical SteelTested at 17 kG (1.7 T) in Accordance with Test Method A343/A343MASTMCore-LossTypeAAimThickness,Bin. (mm)Maximum Specific CoreLoss,C
26、W/lb (W/kg)60 Hz 50 Hz23P060 0.0090 (0.23) 0.60 (1.32) 0.46 (1.01)27P066 0.0106 (0.27) 0.66 (1.46) 0.50 (1.11)Laser-Scribed High-Permeability Grain-Oriented Electrical SteelTested at 17 kG (1.7 T) in Accordance with Test Methods A804/A804MASTMCore-LossTypeAAimThickness,Bin. (mm)Maximum Specific Core
27、Loss,DW/lb (W/kg)60 Hz 50 Hz23Q054 0.0090 (0.23) 0.54 (1.19) 0.41 (0.90)27Q057 0.0106 (0.27) 0.57 (1.26) 0.43 (0.96)ASee Practice A664.BThese shall be the overall thicknesses as measured by contacting micrometre caliper.CBased on parallel-grain Epstein specimens, stress-relief annealed after shearin
28、g in accordance with 14.1.2.DBased on as-sheared parallel-grain sheet-type specimens. Stress-relief annealing will nullify the core-loss reduction produced by the laser scribing.A876 122sheared laminations, flat stamped laminations, wound cores,bonded wound cores, formed lamination cores, welded lam
29、i-nation cores, and so forth. This will help the producer toprovide the most suitable material for the users fabricatingpractices), and6.1.11 Exception to the specification or special require-ments.7. Materials and Manufacture7.1 Normally, these steels contain approximately 3.2 %silicon and the bala
30、nce iron with residual elements at aminimum. When requested, the producer shall provide astatement of chemical composition typical of the materialbeing supplied.7.2 These electrical steels may be made by the basic-oxygenor electric-furnace process.7.3 When changes in the manufacture of successive sh
31、ip-ments of the material are believed to increase the likelihood ofadverse effects upon the magnetic performance or fabricationfor the specified end use, the producer shall notify the user assoon as possible before shipment is made so that he can beafforded an opportunity to evaluate the effects.8.
32、Magnetic Properties8.1 Core Loss:8.1.1 Maximum permissible specific core losses at 15 or 17kG (1.5 or 1.7 T), 50 and 60 Hz, are guaranteed and are listedin Table 1 for the ASTM core-loss types. The sampling,specimen preparation, and testing practices that are describedherein must be followed when co
33、nformity to these guaranteesis being checked.8.1.2 Material that conforms to both the core-loss andthickness limits of this specification shall be identified by thisspecification number and the appropriate core-loss designation.8.2 Permeability:8.2.1 The permeability at all magnetic flux densities s
34、hall beas high as practicable. The quality control of these grades isnormally based on a measurement of relative peakpermeability, p, at a peak ac magnetic field strength, Hp,of10Oe (796 A/m). For the conventional grain-oriented grades, thevalue of relative pat 10 Oe (796 A/m) is commonly above1800.
35、 For the high-permeability grades, it is commonly above1880.8.3 Magnetic Aging: Although the magnetic properties ofthese electrical steels are considered to be stable, the maximumcore-loss values of Table 1 are based on tests of non-agedspecimens. The guarantee of magnetic properties after an agingt
36、reatment is subject to negotiation between the user and theproducer.9. Surface Insulation Characteristics9.1 The surfaces types produced in each of the materialconditions of 5.1 normally have different levels of insulatingability. Interlaminar resistance of two adjacent test surfaces isdetermined wi
37、thTest Method A937/A937M. Surface insulationresistivity of a single test surface is determined with TestMethod A717/A717M. Typical ranges for surface insulationeffectiveness of the various surface types are given in Appen-dix X1.9.2 When insulative characteristics substantially differentthan those l
38、isted in Appendix X1 are necessary, the specificrequirements and the procedures for evaluating them shall benegotiated between the user and the producer.10. Physical and Mechanical Properties10.1 Lamination FactorThe lamination factor shall be ashigh as practicable consistent with the material thick
39、ness andcondition. Lamination factor may be determined using TestMethod A719/A719M. Typical lamination factor values for thevarious material thickness and condition combinations areshown in Appendix X1.10.2 DuctilityThe ductility shall be as high as practicable.When the application requires forming
40、around a sharp radiusduring fabrication, and an evaluation of the ductility isrequired, the ductility rating shall be determined in accordancewith Test Method A721/A721M. Ductility ratings in thefollowing classes are appropriate for grain-oriented steels inany thickness and condition when tested at
41、room temperaturewith a bend transverse to the rolling direction with “as-sheared” specimens:Ductility Class Permissible Number of Fractures at BendA1 none2 1 or 2, total length not over 0.5 in. (12.7 mm)3 3 to 8ABased on 24- to 36-in. (610- to 910-mm) width of material. For widths less than24 in. (6
42、10 mm), the number of permissible fractures should be reduced inproportion to the ratio of the width to 24 in. (610 mm).11. Dimensions and Permissible Variations11.1 ThicknessThe aim thicknesses of the ASTM core-loss types are listed in Table 1.11.1.1 Thickness VariationsThe thickness measured atany
43、 location not less than 0.4 in. (10 mm) from an edge shallnot deviate more than 60.001 in. (60.025 mm) from theaverage thickness of the test lot or coil. The outer limits ofacceptable thickness of the ASTM core-loss type shall be asshown in Table 2.11.2 Width TolerancesThe width of material supplied
44、,either as coils or cut lengths, shall be as close as possible to theordered width, but in no case shall the maximum deviationsfrom the specified width exceed the values given in Table 3.11.3 Length TolerancesThe length dimension of cutlengths shall be as close as practicable to the ordered length.T
45、he maximum deviations from ordered length shall be asshown in Table 4.TABLE 2 Thickness TolerancesASTM Core-Loss Type Thickness Limits,in. (mm)18G041 0.0060-0.0080 (0.152-0.203)23G045, 23H070, 23P060, 23Q054 0.0075-0.0100 (0.190-0.254)27G051, 27H074, 27P066, 27Q057 0.0095-0.0120 (0.241-0.305)30G058,
46、 30H083, 30P070 0.0105-0.0130 (0.267-0.330)35G066, 35H094 0.0125-0.0150 (0.318-0.381)A876 12311.4 Camber (Full-Width Coils)The deviation of a sideedge from a straight line over a 96-in. (2440-mm) length orfraction thereof shall not exceed 0.125 in. (3.2 mm).11.5 Out of Square (Cut Lengths)The deviat
47、ion of an endedge from a straight line placed at a right angle to the side,touching one corner and extending to the other side, shall notexceed 0.0625 in./6 in. (1.6 mm/152 mm) of width or fractionthereof.12. Workmanship, Finish, and Appearance12.1 Flatness:12.1.1 Sharp, short waves and buckles are
48、extremely detri-mental to the effective use of grain-oriented electrical steels inflat laminations and shall be avoided in the delivered product.12.1.2 The user shall inform the producer of any require-ments for a degree of flatness more critical than that providedby the usual commercial practices.
49、Procedures for judging orevaluating the degree of flatness in such cases shall be subjectto negotiation between the user and the producer.12.2 Surface DefectsThe surface of the material shall bereasonably clean and essentially free from manufacturingdefects such as holes, mill marks, slivers, and so forth, whichwould interfere with its effective use in the intended applica-tion. The surface shall be free of loose dust and be compatiblewith immersion in the usual liquid transformer coolants.Applied surface coatings shall be reasonably thin, continuousin coverage,
