1、Designation: A924/A924M 141Standard Specification forGeneral Requirements for Steel Sheet, Metallic-Coated bythe Hot-Dip Process1This standard is issued under the fixed designation A924/A924M; the number immediately following the designation indicates the yearof original adoption or, in the case of
2、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.1NOTEIn Table 5, footnotes A and B, reference to Table 14 was corrected to Table 15 in April 2016.1. Scope*1
3、.1 This specification covers the general requirements that,unless otherwise specified in the product 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 p
4、roduct speci-fications contain requirements for specific strength levels, heatresistance, paintability, 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 S
5、teel (DS), Deep DrawingSteel (DDS), Extra Deep Drawing Steel (EDDS), High Tem-perature Steel (HTS), 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 individua
6、l product specifica-tion:1.2.1 Zinc or zinc-iron alloy coated,1.2.2 Zinc-5 % aluminum alloy coated,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-ca
7、tion are described in the following product standards: Speci-fications A308/A308M; A463/A463M; A653/A653M; A755/A755M; A792/A792M; A875/A875M; A929/A929M; A1046/A1046M; A1057/A1057M; A1063/A1063M; and A1079.1.4 Metallic-coated steel sheet is produced to various coat-ing designations, as shown in the
8、 individual product specifica-tions. Except for differentially coated sheet, the coating isalways expressed as the total 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 specificatio
9、n.1.6 The purchaser is permitted to specify additional require-ments that do not negate any of the provisions of this generalspecification or of the individual product specifications. Suchadditional requirements, the acceptance of which are subject tonegotiation with the supplier, shall be included
10、in the orderinformation.1.7 For purposes of determining conformance with thisspecification and the various product specifications 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
11、strength values) inaccordance with the rounding method of Practice E29.1.8 Metallic-coated steel sheet covered by this 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
12、text of this specification references notes andfootnotes that provide explanatory material. These notes andfootnotes (excluding those in tables and figures) shall not beconsidered as requirements of the specification.1.10 The values stated in inch-pound units or SI units are tobe regarded separately
13、 as standard. Within the text, the SI unitsare shown in brackets. The values stated in each system are notexact equivalents; therefore, each system must be used inde-pendently of the other.1.11 This specification and some of the applicable productspecifications are expressed in both inch-pound and S
14、I units.However, unless the order specifies the applicable “M” speci-fication designation (SI units), the product shall be furnished toinch-pound units.1.12 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of th
15、is standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1This specification is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibility of Subcom-mittee A0
16、5.11 on Sheet Specifications.Current edition approved Oct. 1, 2014. Published October 2014. Originallyapproved in 1994. Last previous edition approved in 2013 as A924/A924M - 13.DOI: 10.1520/A0924_A0924M-14E01.*A Summary of Changes section appears at the end of this standardCopyright ASTM Internatio
17、nal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA308/A308M Specification for Steel Sheet, Terne (Lead-TinAlloy
18、) Coated by the Hot-Dip Process (Withdrawn 2015)3A309 Test Method for Weight and Composition of Coatingon Terne Sheet by the Triple-Spot Test (Withdrawn 2015)3A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA428/A428M Test Method for Weight Mass of Coating onAluminum-Coated
19、Iron or Steel ArticlesA463/A463M Specification for Steel Sheet, Aluminum-Coated, by the Hot-Dip ProcessA653/A653M Specification for Steel Sheet, Zinc-Coated(Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed)by the Hot-Dip ProcessA700 Guide for Packaging, Marking, and Loading Methodsfor Steel Produ
20、cts for ShipmentA751 Test Methods, Practices, and Terminology for Chemi-cal Analysis of Steel ProductsA754/A754M Test Method for Coating Weight (Mass) ofMetallic Coatings on Steel by X-Ray FluorescenceA755/A755M Specification for Steel Sheet, Metallic Coatedby the Hot-Dip Process and Prepainted by t
21、he Coil-Coating Process for Exterior Exposed Building ProductsA792/A792M Specification for Steel Sheet, 55 %Aluminum-Zinc Alloy-Coated by the Hot-Dip ProcessA875/A875M Specification for Steel Sheet, Zinc-5 % Alu-minum Alloy-Coated by the Hot-Dip ProcessA902 Terminology Relating to Metallic Coated St
22、eel Prod-uctsA929/A929M Specification for Steel Sheet, Metallic-Coatedby the Hot-Dip Process for Corrugated Steel PipeA1030/A1030M Practice for Measuring Flatness Character-istics of Steel Sheet ProductsA1046/A1046M Specification for Steel Sheet, Zinc-Aluminum-Magnesium Alloy-Coated by the Hot-Dip P
23、ro-cessA1057/A1057M Specification for Steel, Structural Tubing,Cold Formed, Welded, Carbon, Zinc-Coated (Galvanized)by the Hot-Dip ProcessA1063/A1063M Specification for Steel Sheet, Twin-RollCast, Zinc-Coated (Galvanized) by the Hot-Dip ProcessA1079 Specification for Steel Sheet, Complex Phase (CP),
24、Dual Phase (DP) and Transformation Induced Plasticity(TRIP), Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip ProcessE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE376 Practice for Measuring Coating Thickness byMagne
25、tic-Field or Eddy-Current (Electromagnetic) Test-ing Methods2.2 Federal Standard:4Fed. Std. No. 123 Marking for Shipment (Civil Agencies)3. Terminology3.1 DefinitionsFor definitions of items used in thisspecification, refer to Terminology A902.4. Ordering Information4.1 Ordering information for all
26、products are shown in theindividual 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
27、 % aluminum-zinc alloy, zinc-5 %aluminum 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
28、to obtain product information.5.2 Hot-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 intend
29、ed application.6. Chemical Composition6.1 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,manganese, phosphorus, sulfur, and an
30、y other elements speci-fied or restricted 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 technologic
31、allysuited to product analysis due 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 nottechnological
32、ly appropriate because of segregation 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 o
33、f more than one mill liftor coil is involved, at least six pieces shall be selected.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 p
34、age onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Yale University Library, Standardization Documents OrderDesk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 191115094, Attn:NPODS.A924/A924M 14126.1.3.4 When supplying H
35、igh-Strength Low-Alloy Steel(HSLA), some producers use one or more microalloyingelements as strengthening agents or use alloy additions to effectinclusion control, or both. The producer shall be consulted forthe specific chemical composition applied. If any alloyingaddition is known to be of concern
36、 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 A751 shall beused.6.2
37、 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.7. Tests for Mechanic
38、al 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 A370. Requirements for allmechanical properties are included in the
39、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 for rectangular tensio
40、n test specimens of Test MethodsA370.7.2.1.1 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 shalldetermine the method to be use
41、d; 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 before testing on an end of
42、 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. Tests for Coating Proper
43、ties8.1 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 is ordered as total bothsides requirements, or if requested on those product specifica-tions permitting it, to single si
44、de/single spot coating massrequirements.8.1.3 Total both sides requirements8.1.3.1 The coating weight mass of equally coated productis the total amount on both sides of the sheet, expressed inounces per square foot grams per square metre of sheet.8.1.3.2 For differentially coated product, the coatin
45、g weightmass on each surface is nominally one half of the statedcoating designation.8.1.4 Single side/single spot requirements8.1.4.1 The coating mass for each surface shall be specifiedseparately, for example, 60G60G, and each single spot testshall meet the specified requirements for the coating de
46、signa-tion.8.2 Coating Weight Mass TestsOne of the following testmethods shall be used:8.3 Weigh-Strip-Weigh Method:8.3.1 The weigh-strip-weigh method, described in TestMethods A90/A90M, A309, and A428/A428M, is a destructivetest that determines coating weight mass by measuring thedifference in weig
47、ht mass between a coated and a stripped(uncoated) sample. If one surface is protected suitably duringthe initial stripping, coating weight mass can be determinedfor each surface independently.8.3.2 Test specimens for product over 18 in. 450 mm inwidth shall be taken from a representative sample piec
48、eapproximately 1 ft 300 mm in length by the associated width.Three test specimens shall be taken from the sample, one fromthe 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
49、 mm2.8.3.3 For product 18 in. 450 mm in width and narrower,only one test specimen is required. Specimens shall be at least2 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.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 0.05Manganese To 0.60, incl 0.03 0.03O
