1、Designation: A1079 12A1079 13Standard 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 n
2、umber immediately 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.1. Sco
3、pe Scope*1.1 This specification covers steel sheet, complex phase (CP) grade, dual phase (DP) grade, and transformation inducedplasticity (TRIP) grade, zinc-coated (galvanized) or zinc-iron alloy-coated (galvannealed) by the hot-dip process in coils and cutlengths.1.2 The product is produced in vari
4、ous zinc or zinc-iron alloy-coating masses or coating designations as shown in Table 1.1.3 Product furnished under this specification shall conform to the applicable requirements of the latest issue of SpecificationA924/A924M, unless otherwise provided herein.1.4 The product is available in a number
5、 of designations and grades with mandatory chemical requirements and mandatorymechanical properties that are achieved through thermal or thermal-mechanical treatments, and are designed to be compatible withautomotive application requirements.1.5 The grade designation nomenclature of the product diff
6、ers from other hot-dip sheet products having mandatory mechanicalproperties in that ordering is to tensile, rather than yield strength values.1.6 The values stated in SI units are to be regarded as the standard.1.7 The text of this specification references notes and footnotes that provide explanator
7、y material. These notes and footnotes,excluding those in tables and figures, shall not be considered as requirements of this specification.1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard t
8、o establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2A90/A90M Test Method for Weight Mass of Coating on Iron and Steel Articles with Zinc or Zinc-Alloy CoatingsA370 Test Methods and Defini
9、tions for Mechanical Testing of Steel ProductsA902 Terminology Relating to Metallic Coated Steel ProductsA924/A924M Specification for General Requirements for Steel Sheet, Metallic-Coated by the Hot-Dip ProcessD7396 Guide for Preparation of New, Continuous Zinc-Coated (Galvanized) Steel Surfaces for
10、 PaintingE646 Test Method for Tensile Strain-Hardening Exponents (n -Values) of Metallic Sheet Materials3. Terminology3.1 DefinitionsSee Terminology A902 for definitions of general terminology relating to metallic-coated hot-dip products.3.2 Definitions of Terms Specific to This Standard:1 This test
11、 method is under the jurisdiction of ASTM Committee A05 on Metallic-Coated Iron and Steel Products and is the direct responsibility of Subcommittee A05.11on Sheet Specifications.Current edition approved Sept. 1, 2012April 1, 2013. Published September 2012April 2013. DOI: 10.1520/A1079-12Originally a
12、pproved in 2012. Last previous editionapproved in 2012 as A1079 - 12. DOI:10.1520/A1079-12.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Sum
13、mary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommend
14、s that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W
15、est Conshohocken, PA 19428-2959. United States13.2.1 complex phase (CP) steel, nsteel sheet with a ferritic/bainitic matrix containing small amounts of retained austenite,austenite, and/or pearlite where significant grain refinement is caused by retarded crystallization or precipitation of microallo
16、yingelements.3.2.2 dual phase (DP) steel, nsteel sheet with a ferritic matrix containing a martensitic phase present in the form of islands.3.2.3 transformation induced plasticity (TRIP) steel, nsteel sheet with a mainly ferritic matrix containing retained austenitewhere, during the forming process,
17、 retained austenite can transform to martensite.3.2.4 zinc-iron alloy, na dull grey coating with no spangle pattern that is produced on hot-dip zinc-coated steel sheet.3.2.4.1 DiscussionZinc-iron alloy coating is composed entirely of inter-metallic alloys. It is typically produced by subjecting the
18、hot-dip zinc-coatedsteel sheet to a thermal treatment after it emerges from the molten zinc bath. This type of coating is suitable for immediate paintingwithout further treatment except normal cleaning (refer to Guide D7396). The lack of ductility of the alloy coating presents apotential for powderi
19、ng.4. Classification4.1 The material is available in several designations and grades 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 Transformation induced
20、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 designationsas shown in Table 1.4.2.1 The material is available with the same or different coating designations on each surface.
21、5. Ordering Information5.1 Zinc-coated or zinc-iron alloy-coated sheet in coils and cut lengths is produced to thickness requirements expressed to 0.01mm. The thickness of the sheet includes both the base metal and the coating.5.2 Orders for product to this specification shall include the following
22、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/420Y, o
23、r 980T/550Y), or TRIP (Grades 690T/410Y or 780T/440Y).5.2.3 ASTM designation number and year of issue, as A1079.5.2.4 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),5.2
24、.9 Phosphatized (if required),TABLE 1 Mass of Coating RequirementsANOTE 1Use the information provided in 8.1.2 to obtain the approximate coating thickness per side from the coating mass.Single Spot/Single Side Coating MassCoating Designation Minimum, g/m2 Maximum, g/m2Zinc 20G 20 7030G 30 8040G 40 9
25、045G 45 9550G 50 10055G 55 10560G 60 11070G 70 12090G 90 160100G 100 200Zinc-Iron Alloy 30A 30 80Zinc-Iron Alloy 30A 30 6040A 40 7045A 45 7550A 50 80AThe coating designation is the term by which the minimum single spot/single side coating mass is specified for each side.A1079 1325.2.10 Dimensions (s
26、how thickness, minimum or nominal, width, flatness requirements, and length, (if cut lengths).5.2.11 Coil size requirements (specify maximum outside diameter (OD), acceptable inside diameter (ID), and maximum mass),5.2.12 Packaging,5.2.13 Certification, if required, heat analysis and mechanical prop
27、erty 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, Coating Designation45A45A, not chemically treated, oiled, minimum 1.0
28、0 by 1200 mm by coil, 1520 mm maximum OD, 600 mm ID, 10 000 kg maximum, for B side pillar.NOTE 2The purchaser should be aware that there are variations in manufacturing practices among the producers and therefore is advised to establishthe producers standard (or default) procedures for thickness tol
29、erances.6. Chemical Composition6.1 Base Metal:6.1.1 The heat analysis of the base metal shall conform to the requirements shown in Table 2.6.1.2 Each of the elements listed in Table 2 shall be included in the report of heat analysis, including each element in columnswith grouped elements. When the a
30、mount of copper, nickel, chromium, or molybdenum is less than 0.02 %, report the analysisas either 0.02 % or the actual determined value.When the amount of vanadium, titanium, or columbiumniobium is less than 0.008%, report the analysis as either 0.008 % or the actual determined value.NOTE 3Niobium
31、is also known as Columbium.6.1.3 See Specification A924/A924M for chemical analysis procedures and product analysis tolerances.6.2 Zinc Bath AnalysisThe bath metal used in continuous hot-dip galvanizing shall contain not less than 99 % zinc.NOTE 4To control alloy formation and promote adhesion of th
32、e zinc coating with the steel base metal, the molten coating metal composition normallycontains a percentage of aluminum usually in the range from 0.05 to 0.25. This aluminum is purposely supplied to the molten coating bath, either as aspecified ingredient in the zinc spelter or by the addition of a
33、 master alloy containing aluminum.7. Mechanical Properties7.1 All designations and grades shall conform to the mechanical property requirements in Table 3.7.1.1 All designations and grades shall conform to bake hardening index requirements included in Table 3. The minimumincrease in yield strength i
34、s based on the lower yield stress, after a prestrained specimen has been exposed to a standard bake cycleof 170C for 20 minutes. The method for measuring the bake hardening index is described in the Annex A1.7.2 Mechanical property tests shall be conducted in accordance with the methods specified in
35、 Specification A924/A924M, orthose prescribed by the purchaser.7.3 Bending Properties Minimum Cold Bending RadiiHigh-strength sheet steels are commonly fabricated by cold bending.There are many interrelated factors that affect the ability of a steel to cold form over a given radius under shop condit
36、ions. Thesefactors include thickness, strength level, degree of restraint, relationship to rolling direction, chemistry, and base metalmicrostructure. The table in Appendix X1 lists the suggested minimum inside radius for 90 cold bending for the grades steel ofTABLE 2 Chemical RequirementsA Steel Sh
37、eet Designations CP, DP, and TRIPComposition, %Heat Analysis Element, max (unless otherwise shown)Designation/GradeC Mn+Al+SiC P S CuB Ni Cr+MoC V+Cb+TiC NDesignation/GradeC Mn+Al+SiC P S CuB Ni Cr+MoC V+NbD +TiC NCP600T/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
38、 0.20 0.50 1.00 0.35 .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
39、.23 6.00 0.080 0.015 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 i
40、s a minimum requirement. 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).A1079 133steel in this specification. They presuppose “hard way”
41、bending (bend axis parallel to rolling direction) and reasonably good shopforming practices. Where possible, the use of larger radii or “easy way” bends is recommended for improved performance.8. Coating Properties8.1 Coating Mass:8.1.1 Coating mass shall conform to the requirements as shown in Tabl
42、e 1 for the specific coating designation.8.1.2 Use the following relationships to estimate the coating thickness from the coating mass:8.1.2.1 7.14 g/m2 coating mass = 1.00 m coating thickness.8.1.3 The ordering format for specifying the coating for each surface shall be, for instance, 45A45A. In th
43、e case of differentiallycoated product, the thicker (heavier) coating mass side shall be specified first, for instance 50A30A.8.2 Coating Mass Tests:8.2.1 Coating mass tests shall be performed in accordance with the requirements of Specification A924/A924M.8.2.2 The referee method to be used shall b
44、e Test Method A90/A90M.8.3 Coating Bend Test:8.3.1 The designations and grades in this specification are not subject to coating bend tests.9. Retests and Disposition of Non-Conforming Material9.1 Retests, conducted in accordance with the requirements of the section on Retests and Disposition of Non-
45、ConformingMaterial of Specification A924/A924M, are permitted when an unsatisfactory test result is suspected to be the consequence of thetest method procedure.9.2 Disposition of non-conforming material shall be subject to the requirements of Specification A924/A924M.10. Dimensions and Permissible V
46、ariations10.1 All dimensions and permissible variations shall comply 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; steel sheet;transformation induced plasticity steel;
47、 zinc; zinc iron-alloy; zinc coated (galvanized); zinc iron-alloy coated (galvannealed)TABLE 3 Mechanical Property Requirements, Base Metal (Longitudinal) Steel Sheet Designations CP, DP, and TRIPADesignation Grade Yield Strength, min,MPaTensile Strength,min, MPaElongation in 50mm, min, %n ValueB Ba
48、ke 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 30590T/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 78
49、0 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.A1079 134ANNEX(Mandatory Information)A1. BAKE HARDENABLE INDEXA1.1 Determination of Bake Hardening IndexA1.1.1 The bake hardening index (BHI) is determined by a two-step procedure using a standard longitudinal (rolling direction)tensile-test specimen, prepared in accordance with Test Methods A370. The test specimen is first strained in tension. Themagnitude of this tensile “pre
