1、 WORLDWIDE ENGINEERING STANDARDS Material Specification GMW3399 Multi-phase and Ultra-high Strength Sheet Steel Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 1 of 17 1 Scope This specification covers the requirements for continuous cast, hot rolled or cold rolled sheet
2、steel with specified tensile strengths from 450 MPa through 1700 MPa. 1.1 Material Description. This specification applies to uncoated and coated, Dual Phase (ferrite + martensite) (DP), ferrite bainite with high hole expansion (FB), Transformation Induced Plasticity (ferrite + bainite + retained au
3、stenite) (TRIP or TR), Multi-phase (ferrite + martensite + bainite + precipitation hardening) (MP) or Martensitic (MS) materials. These products shall be supplied as coils or sheets. Hot rolled flat products are usually supplied in thicknesses greater than 1.80 mm. Cold rolled flat products with the
4、 appropriate surface type and surface finish are suitable for the application of surface coatings, metallic hot dipping, electrolytic plating, hot spray painting, organic coatings and/or other coatings. This specification does not apply to steel for case hardening and cold reduced, work hardened str
5、ips. Additional requirements or agreements have to be specified by local business units, e.g., North America (NA), Europe (E), Latin America (LA), and Asia Pacific (AP). The CR1180T/825Y-MP has been added to this version of the specification and is intended for roll forming and simple bending/flange
6、 applications requiring high strength. CR980T/700Y-MP-LCE shall only be used for roll forming, simple bending/flange applications, and targeted stamping applications. Steel used for parts containing the CR980T/650Y-DP specification shall meet the CR980T/700Y-MP requirements in this revision. New par
7、ts shall not contain the CR980T/650Y-DP specification. 1.2 Symbols. Not applicable. 1.3 Typical Applications. Typical applications include body panels, body structure members, chassis components and bumpers. 2 References Note: Only the latest approved standards are applicable unless otherwise specif
8、ied. 2.1 External Standards/Specifications. AS 1391 EN 10247 ISO/TS 16630 SEP 1970 ASTM A751 ISO 6892 ISO/TS 16949 ASTM E45 ISO 7438 JIS Z 2201 ASTM E112 ISO 10275 SAE/USCAR-5 2.2 GM Standards/Specifications. GMW8 GMW3335 GMW14729 GMW16066 GMW11 GMW14057 GMW14829 GMW16170 GMW3011 GMW14058 GMW14872 G
9、MW16546 GMW3059 GMW14699 GMW15056 GMW16549 GMW3221 GMW14700 GMW15282 GMW16823 GMW3224 GMW14704 GMW15425 2.3 Additional References. GWS-5A TMC003 Material Safety Data Sheet guidance documents (available at ) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot
10、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3399 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 2 of 17 3 Requirements The following section defines specific requirements for material on delivery,
11、processing, performance and other stages during life cycle. Deviations required for individual GM business units are listed in the Deviations. 3.1 Requirements on Delivery. 3.1.1 Chemical Requirements. 3.1.1.1 Base Metal. Base metal composition based on product (coil or sheet/blanks) analysis determ
12、ined per ASTM A751 shall conform to the grade specific requirements in Table A1. When end-product (coil/blank) test results are not available, heat analysis may be used. Chemical composition on the end product is the referee method. 3.1.1.2 Surface Treatment. Products coated with a designated lubric
13、ant (e.g., mill oil or pre-lube) shall comply with GMW16546 and/or be approved by the local business unit. See the Deviations section in Appendix Deviations. 3.1.2 Mechanical Requirements. The steel products shall meet the mechanical properties as specified in Tables A2 thru A8. The 0.2% Offset Yiel
14、d Strength, Tensile Strength, Percent Total Elongation and BH2-values shall be determined in the longitudinal direction per GMW3335. Tests shall be performed using samples per ISO 6892 Type I (50 mm gage length ASTM type sample), ISO 6892 Type II (80 mm gage length DIN type sample) or JIS Z 2201 (nu
15、mber 5). Strain hardening exponent n and K values shall be determined per ISO 10275. The specific strain level shall be reported with all test results. Strain hardening exponent n and K value shall be determined at 10 to 20% strain, or at 10% to end of uniform elongation when uniform elongation is l
16、ess than 20%, but greater than 12%. If the maximum uniform elongation is less than 12%, the strain hardening exponent shall be reported as the true strain at the end of uniform elongation (nU.E. = U.E.) Dual Phase grades require an additional determination of n value at 4 to 6% strain. The specific
17、strain range shall be reported with all test results. 3.1.2.1 Mechanical Property Requirements of Dual Phase (DP), Ferrite Bainite (FB), Transformation Induced Plasticity (TR), Multi-phase (MP) and Martensitic (MS) Grades of hot rolled, cold reduced, uncoated and coated sheet steel grades are based
18、on the minimum as-received tensile strength. Some steels (DP, TR, and MP) have the additional requirement of a Bake Hardening Index (BHI). Where required, the material shall attain an increase in lower yield strength as specified in the appropriate table after 2% tensile strain and baking at 170 C f
19、or 20 minutes. Figure B1 in Appendix B defines Bake Hardening and Work Hardening Indexes. Note: The bake hardening index in this specification is a parameter that characterizes the general bake hardening response of steel. The actual or measured bake hardening response for production parts depends o
20、n a number of factors that must be considered. The amount of strain, the direction of strain relative to the test direction, the actual part temperature/time in the paint bake ovens, etc., may all impact the observed bake hardening response. 3.1.2.2 Bend Test Requirements for Martensitic (MS) and Mu
21、lti-phase (MP) Grades. Testing shall be performed according to ISO 7438, by utilizing a bending device consisting of a V-block and a former or two low friction mounted test rollers and a former. Martensitic steels (MS) and Multi-phase steels (MP) must meet the bending radii as specified in Tables A2
22、, A4, A7 and D1 for a bending angle of 90. Following the test, samples shall be free from visual cracking. 3.1.2.3 Mechanical Property Requirements of Ferrite Bainite (FB) Grades. Ferrite Bainite grades must meet the requirements of the hole expansion test as shown in Table A8. Testing shall be perf
23、ormed per ISO/TS 16630. 3.1.3 Physical Requirements. 3.1.3.1 Material Thickness and Tolerance. The detailed engineering part drawing or electronic math file will specify the material thickness and tolerance. The tolerance requirements for various thicknesses and strength levels are listed in GMW3224
24、. 3.1.3.2 Surface Requirements. 3.1.3.2.1 Surface Texture. Specific requirements for the texture for each region are detailed in GMW16823. 3.1.3.2.2 Surface Quality. The surface condition shall meet the requirements of GMW16823. The steel shall be free from surface defects as negotiated between purc
25、haser and supplier. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3399 Copyright 2013 General Motors Company All Rights Reserved Januar
26、y 2013 Page 3 of 17 3.1.3.2.3 Additional Surface Requirements of Hot Rolled Products. Uncoated hot rolled products shall be supplied in a pickled (de-scaled) and oiled condition to ensure an adequate processability and a good adhesion of applied coatings. Hot rolled steels may be slightly skin-passe
27、d at the discretion of the supplier or with agreement by General Motors. 3.1.3.2.4 Pre-Treatment Compatibility/Paint Adhesion (Qualification Testing). When tested with approved phosphate systems, uncoated or zinc-based coated steels shall be capable of achieving a high quality zinc phosphate convers
28、ion coating according to GMW3011 (crystal size and coating weight). When tested with approved thin film pre-treatments, the requirements of GMW16170 (coating weight and thickness) must be fulfilled. Steels with thin organic pre-coatings per GMW15056 are excluded from these requirements; as a pre-tre
29、atment will not be deposited. However, the additional requirements below must be met for thin film organic pre-coating qualification. After application of production representative pre-treatment and paint, the steel shall meet the following requirements: 1. Adhesion of the E-coat shall fulfill test
30、requirements of the crosshatch test according to GMW14829: For samples that are phosphated: rating 0 as-received and after 120 hours humidity exposure per GMW14729. For samples with thin film pre-treatment, requirements according to GMW16170 must be met. 2. Pretreated (zinc Phosphate or thin film) a
31、nd E-coated samples must meet delamination test requirements according to GMW14704 (rating 0 or 1 after 48 hours test duration). 3. For fully painted applications on exposed (E) surfaces, the material shall also meet the requirements of the stone chip resistance test according to GMW14700, Method A
32、(or B) and Method C, with a minimum stone impact rating of 8. 4. Creep back resistance shall be inspected on E-coated samples. The samples shall be scribed per GMW15282 and tested according to GMW14872, EXT, All, 4 salt spray per cycle, Method 1/2/3, exposure C. The creep back shall be evaluated per
33、 GMW15282 and meet the requirements stated in the following specifications: GMW3011 for samples that are phosphated GMW16170 for samples with thin film pre-treatment GMW15056 for samples with thin organic pre-coating (applicable to thin film organic coating qualification only) 3.1.3.2.5 Adhesive Com
34、patibility (Qualification Testing). Uncoated or zinc-based coated steels supplied to this specification shall be capable of being bonded with GM approved adhesives when tested according GMW16549. Testing to this specification will evaluate bonding characteristics to the metal surface. 3.1.3.2.6 Coat
35、ing Requirements. Refer to coating requirements in GMW8 for hot dipped coatings, GMW11 for electrogalvanized coatings, GMW16066 for aluminized coatings, and GMW15056 for thin organic pre-coatings. Coating requirements include, but are not limited to coating composition, coating mass, and coating adh
36、esion. 3.1.3.3 Microstructure. 3.1.3.3.1 Grain Size. During steel qualification, grain size shall be tested to ASTM E112 and shall be consistent throughout the thickness of the sheet. 3.1.3.3.2 Segregations and Material Inhomogeneties and Cleanliness. Inhomogeneties (e.g., martensite lines, slag inc
37、lusions, segregations) in the steel shall be minimized and should not affect cold forming properties. 3.1.3.3.3 Inclusions. Two (2) optional methods for analysis are available. There should be an agreement with the local business unit as to which of the two following methods has to be performed: Met
38、hod A: ASTM E45 Method D, Plate l-r, by analysis at 100x inclusion content shall not exceed a rating of 2.0 for thin and 2.0 for heavy. Method B: EN 10247: by analysis, inclusions shall not exceed size index 3; in case of diameters smaller than 20 mm; they shall not exceed size index 2. Copyright Ge
39、neral Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW3399 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 4 of 17 3.1.3.4 Mark
40、ing. If required, marking shall be carried out on the unexposed surface of full finish coils for outer panels and on the outer side of the coils for inner panels. The marking must be agreed upon between the supplier and purchaser. The purchaser must release the marking ink. 3.1.3.5 Other Requirement
41、s. Requirements such as tolerances on product shape and dimensions, inspections units, number of tests, sampling, test conditions, retests, inspection documents, packing, and handling of disputes shall be agreed upon between supplier and the local business unit. 3.2 Processing Requirements. 3.2.1 Ad
42、ditional Requirements. 3.2.1.1 Weld Seams in Coils. If weld seams in cold rolled material are allowed by Global Manufacturing Engineering Department, the following restrictions have to be considered: For cold reduced coils, pickling weld seams from the manufacturing process of hot rolled coils is pe
43、rmissible without restriction. Punch holes may be used for cold reduced coils to detect weld seams, but must be avoided in stamped parts. For cold reduced coils with exposed (E) or semi-exposed (Z) surfaces, weld seams are permissible but must be indicated by perforation. For cold reduced coils with
44、 unexposed (U) surfaces, weld seams are not permissible unless special exceptions are made by the local organization. For hot rolled coils, weld seams are not permissible. 3.2.1.2 Welding. Sheet steel supplied to this standard shall be weldable with standard GM Weld Practices and meet spot weld, arc
45、 weld, or laser fillet weld acceptance criteria per GMW14057, GMW14058, or GMW15425, respectively. When required for qualification, testing for spot weldability shall be performed per GWS-5A and approved by the ME-Weld Department of GM Manufacturing Engineering. Contact the GM Weld Council for speci
46、fic information regarding weldability at . Note: The standard weld test methods are intended for yield strength levels up to 420 MPa. Modifications to these methods may be required for higher strength levels. Due to unique properties of multi-phase and ultra-high strength steels, selection of the we
47、ld process parameters should be determined in consultation with the steel supplier. 3.2.1.3 Stretcher Strains. All steel used for exposed (E) surfaces and secondary exposed surfaces shall be free from stretcher strains for six months. 3.3 Performance Requirements. Not applicable. 3.4 Requirements on
48、 Other Stages during Life Cycle. 3.4.1 Chemical Requirements. Provisions must be made to prevent the addition of such elements (see 5.3) from scrap or other materials used in the manufacturing process which would impair the recyclability of the finished components. 3.4.2 Mechanical Requirements. The
49、 mechanical property requirements shown in Tables A2 thru A8, D1 shall be guaranteed for a minimum of 3 months after delivery to the manufacturing plant. For material qualification, required mechanical properties shall be guaranteed for a minimum of 6 months after coil finishing. 3.4.2.1 Hydrogen Embrittlement Sensitivity. All materials supplied to this specification must be free of hydrogen embrittlement sensitivity. Hydrogen generating pro
