1、Designation: A1079 132Standard Specification forSteel Sheet, Complex Phase (CP), Dual Phase (DP) andTransformation Induced Plasticity (TRIP), Zinc-Coated(Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) bythe Hot-Dip Process1This standard is issued under the fixed designation A1079; the number i
2、mmediately following the designation indicates the year oforiginal adoption or, in the case of revision, 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.1NOTETypograp
3、hical errors in Section 3.2.1 and Table X1.1 were corrected editorially in October 2013.2NOTEUnits statement in the Scope was corrected editorially in November 2013.1. Scope*1.1 This specification covers steel sheet, complex phase(CP) grade, dual phase (DP) grade, and transformation inducedplasticit
4、y (TRIP) grade, zinc-coated (galvanized) or zinc-ironalloy-coated (galvannealed) by the hot-dip process in coils andcut lengths.1.2 The product is produced in various zinc or zinc-ironalloy-coating masses or coating designations as shown in Table1.1.3 Product furnished under this specification shall
5、 conformto the applicable requirements of the latest issue of Specifica-tion A924/A924M, unless otherwise provided herein.1.4 The product is available in a number of designations andgrades with mandatory chemical requirements and mandatorymechanical properties that are achieved through thermal orthe
6、rmal-mechanical treatments, and are designed to be com-patible with automotive application requirements.1.5 The grade designation nomenclature of the productdiffers from other hot-dip sheet products having mandatorymechanical properties in that ordering is to tensile, rather thanyield strength value
7、s.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 The text of this specification references notes andfootnotes that provide explanatory material. These notes andfootnotes, excluding those in tables and figures, shall not
8、 beconsidered as requirements of this specification.1.8 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 appro-priate safety and health practices and determine the applica-bility of
9、 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 CoatingsA370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA902 Terminology Relating to Metallic Coa
10、ted Steel Prod-uctsA924/A924M Specification for General Requirements forSteel Sheet, Metallic-Coated by the Hot-Dip ProcessD7396 Guide for Preparation of New, Continuous Zinc-Coated (Galvanized) Steel Surfaces for PaintingE646 Test Method for Tensile Strain-Hardening Exponents(n -Values) of Metallic
11、 Sheet Materials3. Terminology3.1 DefinitionsSee Terminology A902 for definitions ofgeneral terminology relating to metallic-coated hot-dip prod-ucts.3.2 Definitions of Terms Specific to This Standard:3.2.1 complex phase (CP) steel, nsteel sheet with aferritic/bainitic matrix containing small amount
12、s of retainedaustenite, or pearlite, or both where significant grain refinementis caused by retarded crystallization or precipitation of microal-loying elements.1This test method is under the jurisdiction of ASTM Committee A05 onMetallic-Coated Iron and Steel Products and is the direct responsibilit
13、y ofSubcommittee A05.11 on Sheet Specifications.Current edition approved April 1, 2013. Published April 2013. Originallyapproved in 2012. Last previous edition approved in 2013 as A1079 - 13.DOI:10.1520/A1079-13E02.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM
14、Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohock
15、en, PA 19428-2959. United States13.2.2 dual phase (DP) steel, nsteel sheet with a ferriticmatrix containing a martensitic phase present in the form ofislands.3.2.3 transformation induced plasticity (TRIP) steel,nsteel sheet with a mainly ferritic matrix containing retainedaustenite where, during the
16、 forming process, retained austenitecan transform to martensite.3.2.4 zinc-iron alloy, na dull grey coating with no spanglepattern that is produced on hot-dip zinc-coated steel sheet.3.2.4.1 DiscussionZinc-iron alloy coating is composedentirely of inter-metallic alloys. It is typically produced bysu
17、bjecting the hot-dip zinc-coated steel sheet to a thermaltreatment after it emerges from the molten zinc bath. This typeof coating is suitable for immediate painting without furthertreatment except normal cleaning (refer to Guide D7396). Thelack of ductility of the alloy coating presents a potential
18、 forpowdering.4. Classification4.1 The material is available in several designations andgrades as follows:4.1.1 Complex phase (CP) steel (Grades 600T/350Y, 780T/500Y, and 980T/700Y),4.1.2 Dual phase (DP) steel (Grades 440T/250Y, 490T/290Y, 590T/340Y, 780T/420Y, and 980T/550Y), and4.1.3 Transformatio
19、n induced plasticity (TRIP) steel(Grades 690T/410Y and 780T/440Y).4.2 The material is available as either zinc-coated or zinc-iron alloy-coated in several coating masses or coating desig-nations as shown in Table 1.4.2.1 The material is available with the same or differentcoating designations on eac
20、h surface.5. Ordering Information5.1 Zinc-coated or zinc-iron alloy-coated sheet in coils andcut lengths is produced to thickness requirements expressed to0.01 mm. The thickness of the sheet includes both the basemetal and the coating.5.2 Orders for product to this specification shall include thefol
21、lowing information, as necessary, to adequately describe thedesired product:5.2.1 Name of product steel sheet, zinc-coated (galvanized)or zinc-iron alloy-coated (galvannealed),5.2.2 Designation of sheet CP (Grades 600T/350Y, 780T/500Y, or 980T/700Y), DP (Grades 440T/250Y, 490T/290Y,590T/340Y, 780T/4
22、20Y, or 980T/550Y), or TRIP (Grades690T/410Y or 780T/440Y).5.2.3 ASTM designation number and year of issue, asA1079.5.2.4 Coating designation (see 8.1.3),5.2.5 Minimized spangle (if required),5.2.6 Chemically treated or not chemically treated,5.2.7 Oiled or not oiled,5.2.8 Extra smooth (if required)
23、,5.2.9 Phosphatized (if required),5.2.10 Dimensions (show thickness, minimum or nominal,width, flatness requirements, and length, (if cut lengths).5.2.11 Coil size requirements (specify maximum outsidediameter (OD), acceptable inside diameter (ID), and maximummass),5.2.12 Packaging,5.2.13 Certificat
24、ion, if required, heat analysis and mechani-cal property report,5.2.14 Application (part identification and description), and5.2.15 Special requirements (if any).NOTE 1Typical ordering descriptions are as follows: steel sheet,zinc-iron alloy-coated, DP Grade 590T/340Y, ASTM A1079, CoatingDesignation
25、 45A45A, not chemically treated, oiled, minimum 1.00 by1200 mm by coil, 1520 mm maximum OD, 600 mm ID, 10 000 kgmaximum, for B side pillar.NOTE 2The purchaser should be aware that there are variations inmanufacturing practices among the producers and therefore is advised toestablish the producers st
26、andard (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.TABLE 1 Mass of Coating RequirementsANOTE 1Use the information provided in 8.1.2 to obtain the approximate coating
27、thickness per side from the coating mass.Single Spot/Single Side Coating MassCoating Designation Minimum, g/m2Maximum, g/m2Zinc 20G 20 7030G 30 8040G 40 9045G 45 9550G 50 10055G 55 10560G 60 11070G 70 12090G 90 160100G 100 200Zinc-Iron Alloy 30A 30 6040A 40 7045A 45 7550A 50 80AThe coating designati
28、on is the term by which the minimum single spot/single side coating mass is specified for each side.A1079 13226.1.2 Each of the elements listed in Table 2 shall be includedin the report of heat analysis, including each element incolumns with grouped elements. When the amount of copper,nickel, chromi
29、um, or molybdenum is less than 0.02 %, reportthe analysis as either 0.02 % or the actual determined value.When the amount of vanadium, titanium, or niobium is lessthan 0.008 %, report the analysis as either 0.008 % or theactual determined value.NOTE 3Niobium is also known as Columbium.6.1.3 See Spec
30、ification A924/A924M for chemical analysisprocedures and product analysis tolerances.6.2 Zinc Bath AnalysisThe bath metal used in continuoushot-dip galvanizing shall contain not less than 99 % zinc.NOTE 4To control alloy formation and promote adhesion of the zinccoating with the steel base metal, th
31、e molten coating metal compositionnormally contains a percentage of aluminum usually in the range from0.05 to 0.25. This aluminum is purposely supplied to the molten coatingbath, either as a specified ingredient in the zinc spelter or by the additionof a master alloy containing aluminum.7. Mechanica
32、l Properties7.1 All designations and grades shall conform to the me-chanical property requirements in Table 3.7.1.1 All designations and grades shall conform to bakehardening index requirements included in Table 3. The mini-mum increase in yield strength is based on the lower yieldstress, after a pr
33、estrained specimen has been exposed to astandard bake cycle of 170C for 20 minutes. The method formeasuring the bake hardening index is described in the AnnexA1.7.2 Mechanical property tests shall be conducted in accor-dance with the methods specified in Specification A924/A924M, or those prescribed
34、 by the purchaser.7.3 Bending Properties Minimum Cold Bending RadiiHigh-strength sheet steels are commonly fabricated by coldbending. There are many interrelated factors that affect theability of a steel to cold form over a given radius under shopconditions. These factors include thickness, strength
35、 level,TABLE 2 Chemical RequirementsASteel Sheet Designations CP, DP, and TRIPComposition, %Heat Analysis Element, max (unless otherwise shown)Designation/GradeC Mn+Al+SiCPSCuBNi Cr+MoCV+NbD+TiCNCP600T/350Y 0.18 5.30 0.080 0.015 0.20 0.50 1.00 0.35 .780T/500Y 0.18 5.50 0.080 0.015 0.20 0.50 1.00 0.3
36、5 .980T/700Y 0.25 5.20 0.080 0.015 0.20 0.50 1.00 0.35 .DP450T/250Y 0.15 3.00 0.080 0.015 0.20 0.50 1.00 0.35 .490T/290Y 0.15 3.40 0.080 0.015 0.20 0.50 1.00 0.35 .590T/340Y 0.17 4.75 0.080 0.015 0.20 0.50 1.40 0.35 .780T/420Y 0.18 5.40 0.080 0.015 0.20 0.50 1.40 0.35 .980T/550Y 0.23 6.00 0.080 0.01
37、5 0.20 0.50 1.40 0.35 .TRIP690T/410Y 0.32 6.20 0.12 0.015 0.20 0.50 0.60 0.40 .780T/440Y 0.32 6.70 0.12 0.015 0.20 0.50 0.60 0.40 .AWhere an ellipsis (.) appears in the table, there is no requirement but, the analysis shall be reported.BWhen copper is specified, the copper limit is a minimum require
38、ment. When copper steel is not specified, the copper limit is a maximum requirement.CThe producer shall report the individual composition of each element in the grouping.DNiobium (Nb) is also known as Columbium (Cb).TABLE 3 Mechanical Property Requirements, Base Metal (Longitudinal) Steel Sheet Desi
39、gnations CP, DP, and TRIPADesignation Grade Yield Strength, min,MPaTensile Strength,min, MPaElongation in 50mm, min, %n ValueBBake HardeningIndex, min, MPaLower YieldCP 600T/350Y 350 600 16 30780T/500Y 500 780 10 30980T/700Y 700 980 7 30DP 450T/250Y 250 450 27 $0.16 30490T/290Y 290 490 25 $0.15 3059
40、0T/340Y 340 590 21 $0.14 30780T/420Y 420 780 14 $0.11 30980T/550Y 550 980 8 30TRIP 690T/410Y 410 690 21 $0.19 30780T/440Y 440 780 19 $0.16 30AWhere an ellipsis (. . .) appears in this table, there is no requirement.Bn ValueStrain-hardening exponent as determined by Test Method E646, 10-20 % strain.A
41、1079 1323degree of restraint, relationship to rolling direction, chemistry,and base metal microstructure. The table in Appendix X1 liststhe suggested minimum inside radius for 90 cold bending forthe grades of steel in this specification. They presuppose “hardway” bending (bend axis parallel to rolli
42、ng direction) andreasonably good shop forming practices. Where possible, theuse of larger radii or “easy way” bends is recommended forimproved performance.8. Coating Properties8.1 Coating Mass:8.1.1 Coating mass shall conform to the requirements asshown in Table 1 for the specific coating designatio
43、n.8.1.2 Use the following relationships to estimate the coatingthickness from the coating mass:8.1.2.1 7.14 g/m2coating mass = 1.00 m coating thickness.8.1.3 The ordering format for specifying the coating foreach surface shall be, for instance, 45A45A. In the case ofdifferentially coated product, th
44、e thicker (heavier) coating massside shall be specified first, for instance 50A30A.8.2 Coating Mass Tests:8.2.1 Coating mass tests shall be performed in accordancewith the requirements of Specification A924/A924M.8.2.2 The referee method to be used shall be Test MethodA90/A90M.8.3 Coating Bend Test:
45、8.3.1 The designations and grades in this specification arenot subject to coating bend tests.9. Retests and Disposition of Non-Conforming Material9.1 Retests, conducted in accordance with the requirementsof the section on Retests and Disposition of Non-ConformingMaterial of Specification A924/A924M,
46、 are permitted when anunsatisfactory test result is suspected to be the consequence ofthe test method procedure.9.2 Disposition of non-conforming material shall be subjectto the requirements of Specification A924/A924M.10. Dimensions and Permissible Variations10.1 All dimensions and permissible vari
47、ations shall com-ply with the requirements of Specification A924/A924M.11. Keywords11.1 alloyed coating; complex phase steel; dual phase steel;minimized spangle coating; sheet steel; spangle; steel; steelsheet; transformation induced plasticity steel; zinc; zinc iron-alloy; zinc coated (galvanized);
48、 zinc iron-alloy coated (gal-vannealed)ANNEX(Mandatory Information)A1. BAKE HARDENABLE INDEXA1.1 Determination of Bake Hardening IndexA1.1.1 The bake hardening index (BHI) is determined by atwo-step procedure using a standard longitudinal (rollingdirection) tensile-test specimen, prepared in accorda
49、nce withTest Methods A370. The test specimen is first strained intension. The magnitude of this tensile “pre-strain” shall be 2 %(extension under load). The test specimen is then removedfrom the test machine and baked at a temperature of 170C fora period of 20 minutes. Referring to Fig. A1.1, the bakehardening index (BHI) of the material is calculated as follows:BHI 5 B 2 A (A1.1)where:A = flow stress at 2 % extension under load.B = yield strength upper yield strength (BU) or lower yieldstress (BL) after baking at 170C for 20 minutes.A1.1
