1、Designation: A875/A875M 10Standard Specification forSteel Sheet, Zinc-5 % Aluminum Alloy-Coated by the Hot-DipProcess1This standard is issued under the fixed designation A875/A875M; the number immediately following the designation indicates the yearof original adoption or, in the case of revision, t
2、he 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 steel sheet, in coils and cutlengths, metallic-coated by the hot-dip process, wi
3、th zinc-5 %aluminum alloy coating. The Zn-5Al alloy coating also con-tains small amounts of elements other than zinc and aluminumthat are intended to improve processing and the characteristicsof the coated product.1.2 The coating is produced as two types: zinc-5 %aluminum-mischmetal alloy (Type I) a
4、nd zinc-5 % aluminum-0.1 % magnesium alloy (Type II), and in two coating structures(classes). The coated sheet is produced in several coatingdesignations (coating weight mass).1.3 The material is intended for applications requiringcorrosion resistance, formability, and paintability.1.4 The steel she
5、et is produced in a number of designations,types, grades, and classes designed to be compatible withdiffering application requirements.1.5 Coated sheet material furnished under this specificationshall conform to the applicable requirements of the latest issueof Specification A924/A924M, unless other
6、wise providedherein.1.6 The text of this specification references notes andfootnotes that provide explanatory material. These notes andfootnotes, excluding tables and figures, shall not be consideredas requirements of this specification.1.7 This specification is applicable to orders in eitherinch-po
7、und units (as A875) or metric (SI) units as A875M.Values in inch-pound and SI units are to be regarded separatelyas standard. Within the text, the SI units are shown in brackets.The values stated in each system are not exact equivalents.Therefore, each system shall be used independently of theother.
8、1.8 Unless the order specifies the “M” specification desig-nation (SI units), the material shall be furnished to inch-poundunits.1.9 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish
9、 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating onIron and Steel Articles with Zinc or Zinc-Alloy CoatingsA902 Terminology Relating to Metallic
10、 Coated Steel Prod-uctsA924/A924M Specification for General Requirements forSteel Sheet, Metallic-Coated by the Hot-Dip ProcessB750 Specification for GALFAN (Zinc-5 % Aluminum-Mischmetal) Alloy in Ingot Form for Hot-Dip CoatingsE47 Test Methods for Chemical Analysis of Zinc Die-Casting Alloys3E517 T
11、est Method for Plastic Strain Ratio r for Sheet MetalE646 Test Method for Tensile Strain-Hardening Exponents(n -Values) of Metallic Sheet MaterialsE1277 Test Method for Chemical Analysis of Zinc-5 %Aluminum-MischmetalAlloys by ICP Emission Spectrom-etry2.2 ISO Standard:4ISO 14788 Continuous Hot-Dip
12、Zinc-5 % Aluminum AlloyCoated Steel Sheet and Coils2.3 Other Document:5GF-1 Standard Practice for Determination of Cerium andLanthanum Compositions in Galfan Alloy (5 % Al-0.4 %La-0.4 % Ce-Bal SHG ZN)3. Terminology3.1 DefinitionsSee Terminology A902 for definitions ofgeneral terminology relating to
13、metallic-coated steel products.3.2 Definitions of Terms Specific to This Standard:1This specification 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 Nov.
14、 1, 2010. Published January 2011. Originallyapproved in 1987. Last previous edition approved in 2009 as A875/A875M - 09A.DOI: 10.1520/A0875_A0875M-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
15、ards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from International Lead Zinc Research Organization, Inc., 2525
16、Meridian Parkway, P.O. Box 12036, Research Triangle Park, NC 27709-2036.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.1 minimized coating structure, na coating c
17、haracter-ized by a finer metallurgical coating structure obtained by atreatment designed to restrict the formation of the normalcoarse grain structure formed during solidification of theZn-5A1 alloy coating.3.2.2 regular coating structure, nthe normal coatingstructure resulting from unrestricted gra
18、in growth during nor-mal solidification of the Zn-5Al alloy coating.3.3 Abbreviations:3.3.1 MMmischmetal.3.3.2 Zn-5A1zinc-5 % aluminum.3.3.3 Zn-5Al-Mgzinc-5 % aluminum-0.1 % magnesium.3.3.4 Zn-5Al-MMzinc-5 % aluminum-mischmetal.4. Classification4.1 The material is classified in terms of the base met
19、al andin terms of the coating.4.2 Base Metal Classifications:4.2.1 The material is available in the designations as fol-lows:4.2.1.1 Commercial Steel (CS Types A, B, and C),4.2.1.2 Deep Drawing Steel (DDS),4.2.1.3 Extra Deep Drawing Steel (EDDS),4.2.1.4 Forming Steel (FS Types A and B),4.2.1.5 High-
20、Strength Low-Alloy Steel (HSLAS),4.2.1.6 High-Strength Low-Alloy Steel with ImprovedFormability (HSLAS-F), and4.2.1.7 Structural Steel (SS).4.2.2 Structural Steel and High Strength Low Alloy Steelare available in several grades based on mechanical properties.Structural Steel Grade 50 340 is availabl
21、e in three classesbased on tensile strength.4.3 Coating Classifications:4.3.1 The coating is available in two types, as follows:4.3.1.1 Type IZinc-5 % aluminum-mischmetal (Zn-5Al-MM), and4.3.1.2 Type IIZinc-5 % aluminum-0.1 % magnesium(Zn-5Al-Mg).4.3.2 The coating is available in two coating classes
22、, orstructures, as follows:4.3.2.1 Class AMinimized coating structure, and4.3.2.2 Class BRegular coating structure.4.3.3 The coating is available in several coating designa-tions, or weights masses of coating, as shown in Table 1.4.3.3.1 The coated sheet is available with the same ordifferent coatin
23、g designations on each surface.5. Ordering Information5.1 Zinc-5 % aluminum alloy-coated sheet in coils and cutlengths is produced to thickness requirements expressed to0.001 in. 0.01 mm. The thickness of the sheet includes boththe base metal and the coating.5.2 Orders for coated sheet to this speci
24、fication shall includethe following information, as necessary, to adequately describethe desired product.5.2.1 Name of material (steel sheet, Zn-5Al alloy coated),5.2.2 Designations of sheet steel CS (Type A, B, or C), FS(Type A or B), DDS, EDDS, SS, HSLAS, or HSLAS-F.5.2.2.1 When a CS type is not s
25、pecified, Type B will befurnished.5.2.2.2 When a FS type is not specified, Type B will befurnished.5.2.3 When a SS, HSLAS, HSLAS-F designation is speci-fied, state the grade or combination thereof.5.2.4 ASTM designation number and year of issue, asA875- for inch-pound units or A875M for SI units,5.2
26、.5 Coating type (I or II) (see 4.3.1),5.2.6 Coating designation (see 4.3.3),5.2.7 Class of coating structure (for example, ClassAMinimized, etc.) (see 4.3.2),TABLE 1 Weight Mass of Coating RequirementsA,B,CNOTE 1Use the information provided in 8.1.2 to obtain the approxi-mate coating thickness from
27、the coating weight mass.Minimum RequirementsDTriple-Spot Test Single-Spot TestInch-Pound UnitsCoatingDesignationTotalBoth Sides, oz/ft2One Side,oz/ft2TotalBoth Sides, oz/ft2GF01 no minimum no minimum no minimumGF30 0.30 0.10 0.25GF45 0.45 0.14 0.35GF60 0.60 0.20 0.50GF75 0.75 0.26 0.65GF90 0.90 0.32
28、 0.80GF115 1.15 0.40 1.00GF140 1.40 0.48 1.20GF165 1.65 0.56 1.40GF185 1.85 0.64 1.60GF210 2.10 0.72 1.80GF235 2.35 0.80 2.00SI UnitsCoatingDesignationTotalBoth Sides, g/m2One Side,g/m2TotalBoth Sides, g/m2ZGF001 no minimum no minimum no minimumZGF90 90 30 75ZGF135 135 45 113ZGF180 180 60 150ZGF225
29、225 78 195ZGF275 275 94 235ZGF350 350 120 300ZGF450 450 154 385ZGF600 600 204 510ZGF700 700 238 595AThe coating designation number is the term by which this material is specified.Because of the many variables and changing conditions that are characteristic ofcontinuous hot-dip coating lines, the zin
30、c-5 % aluminum alloy coating is not alwaysevenly divided between the two surfaces of a coated sheet; nor is it always evenlydistributed from edge to edge. However, the minimum triple- spot average coatingmass on any one side shall not be less than 40 % of the single-spot requirement.BAs it is an est
31、ablished fact that the atmospheric corrosion resistance ofzinc-5 % aluminum alloy-coated sheet products is a function of coating thickness(weight mass), the selection of thinner (lighter) coating designations will result inreduced corrosion performance of the Zn-5Al coating. For example, the heavier
32、zinc-5 % aluminum alloy coatings perform adequately in bold atmospheric expo-sure whereas the lighter coatings are often further coated with paint or a similarbarrier coating for increased corrosion resistance. Because of this relationship,material carrying the statement “meets ASTM A875/A875Mrequir
33、ements” shouldalso specify the particular coating type and designation.CThe corrosion performance of Type I Zn-5Al-MM coated sheet products isnonlinear as the corrosion rate decreases with time, due to the formation of acharacteristic passivation layer.DNo minimum value means that there are no estab
34、lished minimum requirementsfor triple- and single-spot tests.A875/A875M 1025.2.8 Chemically treated or not chemically treated,5.2.9 Oiled or not oiled,5.2.10 Extra smooth (if required),5.2.11 Phosphatized (if required),5.2.12 Dimensions (show thickness, minimum or nominal,width, flatness requirement
35、s and length, if cut lengths).5.2.13 Coil size requirements (specify maximum outsidediameter (OD), acceptable inside diameter (ID), and maximumweight mass),5.2.14 Packaging,5.2.15 Certification, if required, and heat analysis and me-chanical property report,5.2.16 Application (part identification an
36、d description), and5.2.17 Special requirements (if any).5.2.17.1 When the purchaser requires thickness tolerancesfor38-in. 10-mm minimum edge distance (see Supplemen-tary Requirement in Specification A924/A924M), this require-ment shall be specified in the purchase order or contract.NOTE 1Typical or
37、dering descriptions are as follows:Steel sheet, Zn-5Al alloy coated to ASTM A875- , CommercialSteelCS Type B, Type I coating, designation GF 115, Class A(minimized coating structure), chemically treated, oiled, 0.040 min by 34by 117 in., for stock tanks.Steel sheet, Zn-5Al alloy coated to ASTM A875M
38、- , StructuralSteelSS Grade 230, Type II coating, designation ZGF 275, Class B(regular coating structure), chemically treated, not oiled, phosphatized,1.00 nominal by 900 mm by coil, 1200 mm max OD, 600 mm ID, 9000kg max, for roof deck.NOTE 2The purchaser should be aware that there are variations in
39、manufacturing practices among the producers and therefore is advised toestablish the producers standard (or default) procedures for thicknesstolerances.6. Chemical Composition6.1 Base Metal:6.1.1 The heat analysis of the base metal shall conform tothe requirements shown in Table 2 for CS (Types A, B
40、, and C),FS (Types A and B), DDS, and EDDS; and in Table 3 for SS,HSLAS, and HSLAS-F.6.1.2 Each of the elements listed in Tables 2 and 3 shall beincluded in the report of heat analysis. When the amount ofcopper, nickel, chromium, or molybdenum is less than 0.02 %,report the analysis either as 0.02 %
41、 or the actual determinedvalue. When the amount of vanadium, titanium, or columbiumis less than 0.008 %, report the analysis either as 0.008 % orthe actual determined value. When the amount of boron is lessthan 0.0005 %, report as 0.0005 % or the actual determinedvalue.6.1.3 See Specification A924/A
42、924M for cast and productanalysis procedures.6.2 Coating Bath Analysis:6.2.1 The bath metal used in continuous hot-dip Zn-5A1-MM alloy coating of Type I shall meet the chemicalcomposition limits specified in Specification B750.6.2.2 The bath metal used in the continuous hot-dip Zn-5Al-Mg alloy coati
43、ng of Type II shall conform to the require-ments of Table 4.6.3 Methods of Analysis:6.3.1 Coating Bath MetalThe determination of chemicalcomposition shall be made in accordance with suitable chemi-cal (Test Method E47 for tin), ICP argon plasma spectrometric(Test Method E1277), or other methods. In
44、case of dispute, theresults secured by Test Method E1277 shall be the basis ofacceptance.6.3.1.1 A practice for X-ray fluorescence spectrometry forthe determination of cerium and lanthanum in a zinc-5 %aluminum-mischmetal has been established by the Interna-tional Lead Zinc Research Organization, as
45、 Practice GF-1.6.3.2 In case of dispute, the results secured by Test MethodE1277 shall be the basis of acceptance.7. Mechanical Properties7.1 Structural steel, high-strength low-alloy steel, and high-strength low-alloy steel with improved formability shall con-form to the mechanical property require
46、ments of Table 5 forthe grade or combination thereof.TABLE 2 Chemical RequirementsAComposition, %Heat Analysis Element, Maximum, Unless Otherwise ShownDesignation C Mn P S Al Cu Ni Cr Mo V Cb TiBNBCS Type AC,D,E0.10 0.60 0.030 0.035 . . . 0.20 0.20 0.15 0.06 0.008 0.008 0.025 . . . . . .CS Type BF,C
47、0.02 to 0.15 0.60 0.030 0.035 . . . 0.20 0.20 0.15 0.06 0.008 0.008 0.025 . . . . . .CS Type CC,D,E0.08 0.60 0.10 0.035 . . . 0.20 0.20 0.15 0.06 0.008 0.008 0.025 . . . . . .FS Type AC,G0.10 0.50 0.020 0.035 . . . 0.20 0.20 0.15 0.06 0.008 0.008 0.025 . . . . . .FS Type BF,C0.02 to 0.10 0.50 0.020
48、0.030 . . . 0.20 0.20 0.15 0.06 0.008 0.008 0.025 . . . . . .DDSD,E0.06 0.50 0.020 0.025 0.01min0.20 0.20 0.15 0.06 0.008 0.008 0.025 . . . . . .EDDSH0.02 0.40 0.020 0.020 0.01min0.20 0.20 0.15 0.06 0.10 0.10 0.15 . . . . . .AWhere an ellipsis (. . .) appears in this table, there is no requirement,
49、but the analysis shall be reported.BFor steels containing more than 0.2 % carbon, titanium is permitted to 0.025 % provided the ratio of % titanium to % nitrogen does not exceed 3.4.CWhen a deoxidized steel is required for the application, the purchaser has the option to order CS and FS to a minimum of 0.01 % total aluminum.DSteel is permitted to be furnished as a vacuum degassed or chemically stabilized steel, or both, at the producers option.EFor carbon levels less than or equal to 0.02 %, vanadium, columbium, or titanium, or combina
