1、Designation: A 875/A 875M 06Standard Specification forSteel Sheet, Zinc-5 % Aluminum Alloy-Coated by the Hot-DipProcess1This standard is issued under the fixed designation A 875/A 875M; the number immediately following the designation indicates the yearof original adoption or, in the case of revisio
2、n, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) 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 proces
3、s, with 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
4、 I) and 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 stee
5、l sheet 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 A 924/A 924M, unles
6、s otherwise providedherein.1.6 This specification is applicable to orders in eitherinch-pound units (as A 875) or metric (SI) units as A 875M.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 syst
7、em are not exact equivalents.Therefore, each system shall be used independently of theother.1.7 Unless the order specifies the “M” specification desig-nation (SI units), the material shall be furnished to inch-poundunits.1.8 The text of this specification references notes andfootnotes that provide e
8、xplanatory material. These notes andfootnotes, excluding tables and figures, shall not be consideredas requirements of this specification.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
9、establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.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 902 Terminology Relating
10、 to Metallic Coated Steel Prod-uctsA 924/A 924M Specification for General Requirements forSteel Sheet, Metallic-Coated by the Hot-Dip ProcessB 750 Specification for Zinc-5 % Aluminum-MischmetalAlloy (UNS Z38510) in Ingot Form for Hot-Dip CoatingsE47 Test Methods for Chemical Analysis of Zinc Die-Cas
11、ting Alloys3E 517 Test Method for Plastic Strain RatioE 646 Test Method for Tensile Strain-Hardening Exponents(n-Values) of Metallic Sheet MaterialsE 1277 Test Method for Chemical Analysis of Zinc-5Aluminum-MischmetalAlloys by ICP Emission Spectrom-etry2.2 ISO Standard:ISO 14788 Continuous Hot-Dip Z
12、inc-5 % Aluminum AlloyCoated Steel Sheet and Coils42.3 Other Document:GF-1 Standard Practice for Determination of Cerium andLanthanum Compositions in Galfan Alloy (5 % Al-0.4 %La-0.4 % Ce-Bal SHG ZN)53. Terminology3.1 DefinitionsSee Terminology A 902 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、. 15, 2006. Published January 2007. Originallyapproved in 1987. Last previous edition approved in 2005 as A 875/A 875M - 05.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
15、efer 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 10036.5Available from International Lead Zinc Research Organization, Inc., 2525Meridian Parkway, P.O. Box 12036, Research Tri
16、angle 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 character-ized by a finer metallurgical coating
17、 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 grain growth during nor-mal solidification of the
18、 Zn-5Al alloy coating.3.3 Abbreviations:3.3.1 MMmischmetal.3.3.2 Zn-5A1zinc-5 % aluminum.3.3.3 Zn-5Al-MMzinc-5 % aluminum-mischmetal.3.3.4 Zn-5Al-Mgzinc-5 % aluminum-0.1 % magnesium.4. Classification4.1 The material is classified in terms of the base metal andin terms of the coating.4.2 Base Metal C
19、lassifications: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 Forming Steel (FS Types A and B),4.2.1.3 Deep Drawing Steel (DDS),4.2.1.4 Extra Deep Drawing Steel (EDDS),4.2.1.5 Structural Steel (SS),4.2.1.6 High-Strength Low-All
20、oy Steel (HSLAS), and4.2.1.7 High-Strength Low-Alloy Steel with ImprovedFormability (HSLAS-F).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 available in three classesbased on tensile strength.4.
21、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, orstructures, as follows:4.3.2.1 Class AMini
22、mized 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 coating designations on each surface.5. Ordering Inf
23、ormation5.1 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 specification shall includethe following informatio
24、n, 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 specified, Type B will befurnished.5.2.2.2 When
25、 a F5 type is not specified, F5 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, asA 875- for inch-pound units or A 875M for SI units,5.2.5 Coating type (I or II) (see 4.3.1),5.2
26、.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 1The coating thickness may be estimated from the coatingweight mass by using Table X2.1.Minimum RequirementsDTriple-Spot Test Sing
27、le-Spot TestInch-Pound UnitsCoatingDesignationTotalBoth Sides, oz/ft2One Side,oz/ft2TotalBoth Sides, oz/ft2GF235 2.35 0.80 2.00GF210 2.10 0.72 1.80GF185 1.85 0.64 1.60GF165 1.65 0.56 1.40GF140 1.40 0.48 1.20GF115 1.15 0.40 1.00GF90 0.90 0.32 0.80GF75 0.75 0.26 0.65GF60 0.60 0.20 0.50GF45 0.45 0.14 0
28、.35GF30 0.30 0.10 0.25GF01 no minimum no minimum no minimumSI UnitsCoatingDesignationTotalBoth Sides, g/m2One Side,g/m2TotalBoth Sides, g/m2ZGF700 700 238 595ZGF600 600 204 510ZGF450 450 154 385ZGF350 350 120 300ZGF275 275 94 235ZGF225 225 78 195ZGF180 180 60 150ZGF135 135 45 113ZGF90 90 30 75ZGF001
29、 no minimum no minimum no minimumAThe 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 zinc-5 % aluminum alloy coating is not alwaysevenly divided between t
30、he 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 established fact that the atmospheric corrosion resistance ofzinc-5 %
31、 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 heavierzinc-5 % aluminum alloy coatings perform adequately in bold atmosp
32、heric 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 “meetsASTMA 875/A 875M requirements” shouldalso specify the particular coating type and design
33、ation.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 established minimum requirementsfor triple- and single-spot tests.A 87
34、5/A 875M 0625.2.8 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, width, flatness require-ments and length, if cut lengths). The purchaser shall specifythe appropriate table o
35、f thickness tolerances in SpecificationA 924/A 924M that applies to the order, that is, the table ofthickness tolerances for38-in. 10-mm edge distance, or thetable of thickness tolerances for 1-in. 25-mm edge distance.5.2.13 Coil size requirements (specify maximum outsidediameter (OD), acceptable in
36、side 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 and description), and5.2.17 Special requirements (if any).NOTE 1Typical ordering descriptions are as follows:Steel
37、 sheet, Zn-5Al alloy coated to ASTM A 875- , 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 A 875M- , StructuralSteelSS Grade 230, Type
38、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 inmanufacturing practices among the prod
39、ucers 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, and C),FS (Types A and B), DDS, and
40、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 % or the actual determinedvalue. When t
41、he 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 A 924/A 924M for cast and productanalysis pr
42、ocedures.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 B 750.6.2.2 The bath metal used in the continuous hot-dip Zn-5Al-Mg alloy coating of Type II shall conform to the
43、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 E47for tin), ICP argon plasma spectrometric(Test Method E 1277), or other methods. In case of dispute, theresults secured
44、 by Test Method E 1277 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 Practice GF-1.6.3.2 In case of di
45、spute, the results secured by Test MethodE 1277 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 requirements of Table 5 forthe grade or
46、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,C0.02 to 0.15 0.60 0.030 0.035 . .
47、 . 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 0.030 . . . 0.20 0.20 0.15 0.06 0
48、.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, but the analysis shall be reporte
49、d.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 combinations thereof are permitted to be
