1、Designation: A1088 13Standard Specification forSteel, Sheet, Cold-Rolled, Complex Phase (CP), Dual Phase(DP) and Transformation Induced Plasticity (TRIP)1This standard is issued under the fixed designation A1088; the number immediately following the designation indicates the year oforiginal adoption
2、 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. Scope1.1 This specification covers cold-rolled, complex phase(CP) grade, dual phase (
3、DP) grade, and transformation inducedplasticity (TRIP) grade steel sheet in coils and cut lengths.1.2 Product furnished under this specification shall conformto the applicable requirements of the latest issue of Specifica-tion A568/A568M, unless otherwise provided herein.1.3 The product is available
4、 in a number of designations andgrades with mandatory chemical requirements and mandatorymechanical properties that are achieved through thermal orthermal-mechanical treatments, and are designed to be com-patible with automotive application requirements.1.4 The grade designation nomenclature of the
5、productdiffers from other cold-rolled sheet products having mandatorymechanical properties in that ordering is to tensile, rather thanyield strength values.1.5 The text of this specification references notes andfootnotes that provide explanatory material. These notes andfootnotes, excluding those in
6、 tables and figures, shall not beconsidered as requirements of this specification.1.6 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all of thesafety concerns, if any, associated wi
7、th 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 regulatory limitations prior to use. Some specifichazards statements are given in Section 7 on Hazards.2. Referenced Documents2.1 ASTM Standards:
8、2A370 Test Methods and Definitions for Mechanical Testingof Steel ProductsA568/A568M Specification for Steel, Sheet, Carbon,Structural, and High-Strength, Low-Alloy, Hot-Rolled andCold-Rolled, General Requirements forA941 Terminology Relating to Steel, Stainless Steel, RelatedAlloys, and Ferroalloys
9、E646 Test Method for Tensile Strain-Hardening Exponents(n -Values) of Metallic Sheet Materials3. Terminology3.1 DefinitionsSee Terminology A941 for definitions ofgeneral terminology relating to cold-rolled steel sheet products.3.2 Definitions:3.2.1 complex phase (CP) steel, nsteel sheet with aferrit
10、ic/bainitic matrix containing small amounts of retainedaustenite or pearlite, or both where significant grain refinementis caused by retarded crystallization or precipitation of microal-loying elements.3.2.2 dual phase (DP) steel, nsteel sheet with a ferriticmatrix containing a martensitic phase pre
11、sent in the form ofislands.3.2.3 transformation induced plasticity (TRIP) steel,nsteel sheet with a mainly ferritic matrix containing retainedaustenite where, during the forming process, retained austenitecan transform to martensite.4. Classification4.1 The material is available in several designati
12、ons 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), and1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Rel
13、ated Alloys and is the direct responsibility of SubcommitteeA01.19 on Steel Sheet and Strip.Current edition approved Nov. 1, 2013. Published November 2013. DOI:10.1520/A1088-132For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. Fo
14、r Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.1.3 Transformation induced plasticity (TRIP) steel(Grades 690T/410Y a
15、nd 780T/440Y).4.2 Cold-rolled steel sheet is supplied for either exposed orunexposed applications. Within the latter category, cold-rolledsheet is specified either “temper rolled” or “annealed last.” Fordetails on processing, attributes and limitations, and inspectionstandards, refer to Specificatio
16、n A568/A568M.5. Ordering Information5.1 It is the purchasers responsibility to specify in thepurchase order all ordering information necessary to describethe required material. Examples of such information include,but are not limited to, the following:5.1.1 ASTM specification number and year of issu
17、e;5.1.2 Name of product (steel sheet, cold-rolled);5.1.3 Designation of sheet CP (Grades 600T/350Y, 780T/500Y, or 980T/700Y), DP (Grades 440T/250Y, 490T/290Y,590T/340Y, 780T/420Y, or 980T/550Y), or TRIP (Grades690T/410Y or 780T/440Y);5.1.4 Finish (see 8.1);5.1.5 Oiled or not oiled (see 8.2);5.1.6 Di
18、mensions (show thickness, minimum or nominal,width, flatness requirements, and length, (if cut lengths);NOTE 1Not all producers are capable of meeting all the limitations ofthe thickness tolerance tables in Specification A568/A568M. The pur-chaser should contact the producer regarding possible limit
19、ations prior toplacing an order.5.1.7 Coil size requirements (specify maximum outsidediameter (OD), acceptable inside diameter (ID), and maximummass);5.1.8 Quantity;5.1.9 Packaging;5.1.10 Certification, if required, heat analysis and mechani-cal property report;5.1.11 Application (part identificatio
20、n and description); and5.1.12 Special requirements (if any).NOTE 2Typical ordering descriptions are as follows: steel sheet,cold-rolled, DP Grade 590T/340Y,ASTMA1088, oiled, minimum 1.00 by1200 mm by coil, 1520 mm maximum OD, 600 mm ID, 10 000 kgmaximum, for side reinforcement strut.6. Chemical Comp
21、osition6.1 The heat analysis of the steel shall conform to therequirements shown in Table 1.6.2 Each of the elements listed in Table 1 shall be includedin the report of heat analysis, including each element incolumns with grouped elements. When the amount of copper,nickel, chromium, or molybdenum is
22、 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.6.2.1 See Specification A568/A568M
23、 for chemical analy-sis procedures and product analysis tolerances.7. Mechanical Properties7.1 All designations and grades shall conform to themechanical property requirements in Table 2.7.1.1 All designations and grades shall conform to bakehardening index requirements included in Table 2. The mini
24、-mum increase in yield strength is based on the lower yieldstress, after a prestrained specimen has been exposed to astandard bake cycle of 170C for 20 min. The method formeasuring the bake hardening index is described in the AnnexA1.7.2 Mechanical property tests shall be conducted in accor-dance wi
25、th the methods specified in Specification A568/A568M, or those prescribed 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 giv
26、en radius under shopconditions. These factors include thickness, strength level,degree of restraint, relationship to rolling direction, chemistry,TABLE 1 Chemical RequirementsASteel Sheet Designations, CP, DP, and TRIPComposition, %Heat Analysis Element, max (unless otherwise shown)Designation/Grade
27、 C 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 0.35 .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
28、.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 0.015 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 (.) appea
29、rs in the table, there is no requirement but, the analysis shall be reported.BWhen copper is specified, the copper limit is 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 th
30、e grouping.DNiobium (Nb) is also known as Columbium (Cb).A1088 132and 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 rolling direct
31、ion) andreasonably good shop forming practices. Where possible, theuse of larger radii or “easy way” bends is recommended forimproved performance.8. Finish and Appearance8.1 Surface Finish:8.1.1 Unless otherwise specified, the sheet shall have amatte finish. When required, specify the appropriate su
32、rfacetexture and condition. For additional information, see theFinish and Condition section of Specification A568/A568M.8.2 Oiling:8.2.1 Unless otherwise specified, the sheet shall be oiled.8.2.2 When required, specify the sheet to be furnished notoiled (dry).9. Retests and Disposition of Non-Confor
33、ming Material9.1 Retests, conducted in accordance with the requirementsof the section on Retests and Disposition of Non-ConformingMaterial of Specification A568/A568M, are permitted when anunsatisfactory test result is suspected to be the consequence ofthe test method procedure.9.2 Disposition of no
34、n-conforming material shall be subjectto the requirements of Specification A568/A568M.10. Dimensions and Permissible Variations10.1 All dimensions and permissible variations shall com-ply with the requirements of Specification A568/A568M.11. Keywords11.1 cold-rolled sheet; complex phase steel; dual
35、phasesteel; steel; steel sheet; transformation induced plasticity steelANNEX(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-te
36、st specimen, prepared in accordance 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
37、. Referring to Fig. A1.1, the bakehardening (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 yieldstrength (BL) after baking at 170C for 20 min.A1.1.2 The original test specimen c
38、ross section (width andthickness) is used in the calculation of all engineering strengthsin this test.A1.1.3 The pre-straining of 2 % in tension is intended tosimulate a modest degree of forming strain, while the subse-quent baking is intended to simulate a paint-curing or similartreatment. In the p
39、roduction of actual parts, forming strains andbaking treatments can differ from those employed here and, asa result; final properties can differ from the values obtainedunder these controlled conditions.TABLE 2 Mechanical Property Requirements (Longitudinal), Cold Rolled Steel Sheet Designations CP,
40、 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 305990T/34
41、0Y 340 590 21 $0.14 30780T/420Y 420 780 14 $0.10 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.A108
42、8 133APPENDIX(Nonmandatory Information)X1. BENDING PROPERTIESX1.1 Table X1.1 lists suggested minimum inside radii forcold bending.FIG. A1.1 Representation of bake Hardening IndexA1088 134ASTM International takes no position respecting the validity of any patent rights asserted in connection with any
43、 item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical
44、committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at
45、 a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor D
46、rive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm
47、.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE X1.1 Suggested Minimum Inside Radii for Cold BendingANOTE 1(t) equals a radius equivalent to the steel thickness.NOTE 2The suggested radii should be used as minimums for 90ben
48、ds in actual shop practice.Designation Grade Minimum InsideRadius for ColdBendingBCP 600T/350Y 2t780T/500Y 3t980T/700Y 4tDP 450T/700Y 112t490T/290Y 2t590T/340Y 2t780T/420Y 212t980T/550Y 3tTRIP 690/410Y 212t780T/440Y 212tAMaterial that does not perform satisfactorily, when fabricated in accordancewith the requirements in this table may be subject to rejection pending negotiationwith the steel supplier.BBending capability may be limited by coating designation.A1088 135
