1、Designation: A 924/A 924M 08Standard Specification forGeneral Requirements for Steel Sheet, Metallic-Coated bythe Hot-Dip Process1This standard is issued under the fixed designationA 924/A 924M; the number immediately following the designation indicates the yearof original adoption or, in the case o
2、f revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This specification covers the general requirements that,unless otherwise specified in the pro
3、duct specification, apply tosteel sheet in coils and cut lengths, metallic-coated on continu-ous lines by the hot-dip process. The product is intended forapplications requiring corrosion resistance. The product speci-fications contain requirements for specific strength levels, heatresistance, painta
4、bility, or formability, or a combinationthereof.1.2 Subject to individual product specification provisions,steel sheet is available as Commercial Steel (CS) Types A, B,and C, Forming Steel (FS), Drawing Steel (DS), Deep DrawingSteel (DDS), Extra Deep Drawing Steel (EDDS), High Tem-perature Steel (HT
5、S), Structural Steel (SS), and High StrengthLow Alloy Steel (HSLAS). Steel sheet is produced with thefollowing metallic coatings. Specific information on each ofthe following is contained in the individual product specifica-tion:1.2.1 Zinc or zinc-iron alloy coated,1.2.2 Zinc-5 % aluminum alloy coat
6、ed,1.2.3 55 % aluminumzinc alloy coated,1.2.4 Aluminumcoated,1.2.5 Terne (lead-tin alloy) coated, and1.2.6 Zinc-aluminum-magnesium alloy coated.1.3 Products covered by this general requirements specifi-cation are described in the following product standards: Speci-fications A 308/A 308M; A 463/A 463
7、M; A 653/A 653M;A 755/A 755M; A 792/A 792M; A 875/A 875M; A 929/A 929M; and A 1046/A 1046M.1.4 Metallic-coated steel sheet is produced to various coat-ing designations, as shown in the individual product specifica-tions. Except for differentially coated sheet, the coating isalways expressed as the t
8、otal coating of both surfaces.1.5 In case of any conflict in requirements, the requirementsof the individual product specifications shall prevail over thoseof this general specification.1.6 The purchaser is permitted to specify additional require-ments that do not negate any of the provisions of thi
9、s generalspecification or of the individual product specifications. Suchadditional requirements, the acceptance of which are subject tonegotiation with the supplier, shall be included in the orderinformation.1.7 For purposes of determining conformance with thisspecification and the various product s
10、pecifications referencedin 1.3, values shall be rounded to the nearest unit in theright-hand place of figures used in expressing the limitingvalues (except to the nearest 5 MPa for SI strength values) inaccordance with the rounding method of Practice E29.1.8 Metallic-coated steel sheet covered by th
11、is specificationis produced to thickness requirements expressed to 0.001 in.0.01 mm for both coils and cut lengths. The thickness is thetotal of the base steel and the coating.1.9 The values stated in inch-pound units or SI units are tobe regarded separately as standard. Within the text, the SI unit
12、sare shown in brackets. The values stated in each system are notexact equivalents; therefore, each system must be used inde-pendently of the other.1.10 This specification and some of the applicable productspecifications are expressed in both inch-pound and SI units.However, unless the order specifie
13、s the applicable “M” speci-fication designation (SI units), the product shall be furnished toinch-pound units.1.11 The text of this specification references notes andfootnotes that provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered a
14、s requirements of the specification.2. Referenced Documents2.1 ASTM Standards:2A 90/A 90M Test Method for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA 308/A 308M Specification for Steel Sheet, Terne (Lead-Tin Alloy) Coated by the Hot-Dip Process1This specificati
15、on is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility ofSubcommittee A05.11 on Sheet Specifications.Current edition approved June 1, 2008. Published June 2008. Originallyapproved in 1994. Last previous edition approved in 2007 a
16、s A 924/A 924M - 07.2For 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.1*A Summary of Changes section appears at
17、 the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.A 309 Test Method for Weight and Composition of Coatingon Terne Sheet by the Triple-Spot TestA 370 Test Methods and Definitions for Mechanical Testingof Steel P
18、roductsA 428/A 428M Test Method for Weight Mass of Coatingon Aluminum-Coated Iron or Steel ArticlesA 463/A 463M Specification for Steel Sheet, Aluminum-Coated, by the Hot-Dip ProcessA 653/A 653M Specification for Steel Sheet, Zinc-Coated(Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed)by the Hot
19、-Dip ProcessA 700 Practices for Packaging, Marking, and LoadingMethods for Steel Products for ShipmentA 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel ProductsA 754/A 754M Test Method for Coating Weight (Mass) ofMetallic Coatings on Steel by X-Ray FluorescenceA 755/A 755M
20、 Specification for Steel Sheet, MetallicCoated by the Hot-Dip Process and Prepainted by theCoil-Coating Process for Exterior Exposed Building Prod-uctsA 792/A 792M Specification for Steel Sheet, 55 %Aluminum-Zinc Alloy-Coated by the Hot-Dip ProcessA 875/A 875M Specification for Steel Sheet, Zinc-5 %
21、Aluminum Alloy-Coated by the Hot-Dip ProcessA 902 Terminology Relating to Metallic Coated Steel Prod-uctsA 929/A 929M Specification for Steel Sheet, Metallic-Coated by the Hot-Dip Process for Corrugated Steel PipeA 1030/A 1030M Practice for Measuring Flatness Charac-teristics of Steel Sheet Products
22、A 1046/A 1046M Specification for Steel Sheet, Zinc-Aluminum-Magnesium Alloy-Coated by the Hot-Dip Pro-cessE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 376 Practice for Measuring Coating Thickness byMagnetic-Field or Eddy-Current (Electromagnetic
23、) Exami-nation Methods2.2 Federal Standard:Fed. Std. No. 123 Marking for Shipment (Civil Agencies)33. Terminology3.1 DefinitionsFor definitions of items used in this speci-fication, refer to Terminology A 902.4. Ordering Information4.1 Ordering information for all products are shown in theindividual
24、 product specifications.5. Materials and Manufacture5.1 Hot-dip metallic coatings are used to provide corrosionprotection to steel sheets. Hot-dip metallic coatings are avail-able in six different types, zinc and zinc-iron alloy, lead-tinalloy (Terne), aluminum, 55 % aluminum-zinc alloy, zinc-5 %alu
25、minum alloy, and zinc-aluminum-magnesium alloy. Eachcoating type is available in various coating weights whichprovide varying degrees of corrosion protection and the con-sumer should consult the individual producers for applicabilityto the intended application and to obtain product information.5.2 H
26、ot-dip metallic coated products may be subject tochanges in mechanical properties after coating. As suchchanges are functions of the chemistry and processing historyof the material, the consumer should consult the individualproducers for applicability to the intended application.6. Chemical Composit
27、ion6.1 Base Steel:6.1.1 Chemical composition requirements of the base steelare shown in the individual product specifications.6.1.2 An analysis of each heat shall be made by themanufacturer to determine the percentage of carbon, manga-nese, phosphorus, sulfur, and any other elements specified orrest
28、ricted by the individual product specification.6.1.3 When desired, product analysis shall be made by thepurchaser on finished product. The product analysis so deter-mined shall meet the tolerances shown in Table 1.6.1.3.1 Capped or rimmed steels are not technologicallysuited to product analysis due
29、to the nonuniform character oftheir chemical composition, and therefore, the tolerances inTable 1 do not apply. Product analysis is appropriate on thesesteels only when misapplication is apparent.6.1.3.2 Product analysis for phosphorus or sulfur is nottechnologically appropriate because of segregati
30、on of theseelements in non-killed steels. Product analysis is appropriateonly when misapplication is apparent.6.1.3.3 Samples for product analysis shall be drillingsthrough areas stripped free of coating. At least three piecesshall be selected, but if the product of more than one mill liftor coil is
31、 involved, at least six pieces shall be selected.6.1.3.4 When supplying High-Strength Low-Alloy Steel(HSLA), some producers use one or more microalloyingelements as strengthening agents or use alloy additions to effect3Available from Yale University Library, Standardization Documents OrderDesk, Bldg
32、. 4 Section D, 700 Robbins Ave., Philadelphia, PA 191115094, Attn:NPODS.TABLE 1 Product Analysis TolerancesElementLimited or Maximum ofSpecified Element, %ToleranceUnderMinimumLimitOverMaximumLimitCarbon To 0.15, incl 0.02 0.03Over 0.15 to 0.40, incl 0.03 0.04Over 0.40 to 0.80, incl 0.03 0.05Mangane
33、se To 0.60, incl 0.03 0.03Over 0.60 to 1.15, incl 0.04 0.04Over 1.15 to 1.65, incl 0.05 0.05Phosphorus . . . . . . 0.01Sulfur . . 0.01Silicon To 0.30, incl 0.02 0.03Over 0.30 to 0.60 0.05 0.05Copper . . . 0.02 . . .Titanium To 0.10, incl 0.01A0.01Vanadium To 0.10, incl 0.01A0.01Over 0.10 to 0.25, in
34、cl 0.02 0.02Minimum only specified 0.01 . . .Columbium To 0.10, incl 0.01A0.01AIf the minimum of the range is 0.01 %, the under tolerance is 0.005 %.A 924/A 924M 082inclusion control, or both. The producer shall be consulted forthe specific chemical composition applied. If any alloyingaddition is kn
35、own to be of concern to the user, the producershall be notified of this concern.6.1.4 Method of AnalysisThe determination of chemicalcomposition is permitted to be made by any test method,except in case of dispute, where the referee test methods listedin the section on test methods of Test Methods A
36、 751 shall beused.6.2 Coating:6.2.1 Coating AnalysisThe nominal composition of thecoating is described in the individual product specification.6.2.2 Method of AnalysisThe determination of chemicalcomposition shall be made in accordance with acceptablechemical, spectrochemical, or other test methods.
37、7. Tests for Mechanical Properties7.1 Test specimens shall be prepared from finished metallic-coated product.7.2 Mechanical Properties-Base MetalWhen base metalmechanical properties are specified, tests shall be conducted inaccordance with Test Methods A 370. Requirements for allmechanical propertie
38、s are included in the individual productspecifications.7.2.1 Tension TestsSpecimens for base-metal tension testsshall be taken longitudinally, approximately midway betweenthe center and edge of the product as rolled, and shall conformto the requirements for the sheet-type test specimen in thefigure
39、for rectangular tension test specimens of Test MethodsA 370.7.2.1.1 The determination of the yield strength and tensilestrength values shall be based on the as-produced base-metalthickness that shall be obtained by one of the followingmethods. Unless specified in the order, the producer shalldetermi
40、ne the method to be used; however, in the event of adispute the method in 7.2.1.2 shall be used.7.2.1.2 The base metal thickness shall be determined bystripping the coating from the ends of the specimen contactingthe grips of the tension testing machine. The thickness mea-surement shall be made befo
41、re testing on an end of thespecimen that has been stripped free of coating.7.2.1.3 The base metal thickness shall be determined bysubtracting the coating thickness from the measured thicknessof the tension test specimen. The coating thickness shall becalculated from the coating weight mass test.8. T
42、ests for Coating Properties8.1 Coating Weight Mass:8.1.1 Coating weight mass shall conform to the require-ments prescribed in the individual product specifications (see1.3).8.1.2 The coating weight mass of equally coated productis the total amount on both sides of the sheet, expressed inounces per s
43、quare foot grams per square metre of sheet.8.1.3 For differentially coated product, the coating weightmass on each surface is nominally one half of the statedcoating designation.8.2 Coating Weight Mass TestsOne of the following testmethods shall be used:8.2.1 Weigh-Strip-Weigh Method:8.2.1.1 The wei
44、gh-strip-weigh method, described in TestMethodsA 90/A 90M,A 309, andA 428/A 428M, is a destruc-tive test that determines coating weight mass by measuringthe difference in weight mass between a coated and a stripped(uncoated) sample. If one surface is protected suitably duringthe initial stripping, c
45、oating weight mass can be determinedfor each surface independently.8.2.1.2 Test specimens for product over 18 in. 450 mm inwidth shall be taken from a representative sample pieceapproximately 1 ft 300 mm in length by the associated width.Three test specimens shall be taken from the sample, one fromt
46、he middle of the width and one from each edge. The edgesamples shall not be taken closer than 2 in. 50 mm from eachedge. The test specimen shall have a minimum area of 5in.23200 mm2.8.2.1.3 For product 18 in. 450 mm in width and narrower,only one test specimen is required. Specimens shall be at leas
47、t2 in. 50 mm from the edge, when possible. For productnarrower than 2.25 in. 60 mm the test specimen shall bechosen to give a minimum area of 5 in.23200 mm2.8.2.1.4 The triple-spot coating weight mass shall be theaverage of the determinations of the three tests done inaccordance with the procedures
48、in 8.2.1.2.8.2.1.5 The minimum single-spot coating weight massshall be that test result that is the lightest coating weightmass, or in those cases where only one test is needed, it shallbe that single test result.8.2.1.6 The frequency of sampling shall be sufficient toadequately characterize the lot
49、 of material being tested.8.2.2 X-Ray Fluorescence Method:8.2.2.1 The X-ray fluorescence method is a nondestructivetest that determines coating weight mass by converting X-rayfluorescence measurements to coating weight mass values.X-ray fluorescence gages can be used as off-line laboratoryinstruments or as a means of continuous on-line testing forconformance to coating weight mass requirements, or both.8.2.2.2 Off-Line TestingX-ray fluorescence gages can beused as off-line laboratory instruments to test for coatingweight
