1、 ENGINEERING MATERIAL SPECIFICATION Material Name Specification Number Date Action Revisions 2013 05 06 N Status No direct replacement, use CBP strategy D. Rhuno, NA 2002 09 30 Revised Rev Revision Box (for 2002 08 19 Revision) R. Lord 2001 12 17 Activated K. J Thurgood (Ford PDE), M Fukahori (Mazda
2、) Controlled document at www.MATS Page 1 of 8 Copyright 2013, Ford Global Technologies, Inc. STEEL, SHEET, COLD ROLLED, TRIP WSS-M1A351-A1/A2/A3 NOT TO BE USED FOR NEW DESIGN 1. SCOPE The materials defined by these specifications are of the cold rolled TRIP (TRansformation Induced Plasticity) type,
3、which includes steel grades with minimum tensile strengths in the range of 600 to 800 MPa (see para 3.5.1). Appropriate steel making practices are used to generate (primarily) austenite as a dispersed second phase in a ferrite matrix. Specification WSS-M1P94-A shall be used where precoating by the s
4、teel supplier is required. (See third note in para 2). 2. APPLICATION These specifications were released originally for commercial vehicle (truck) body (particularly the front end structure) and chassis parts requiring a higher strength to weight ratio, along with improved energy absorption characte
5、ristics and formability than that offered by conventional HSLA (High Strength Low Alloy) steels or Dual Phase (FerriteMartensite) steels. The high strength levels, high degree of work hardening, along with the associated work induced phase transformation of austenite to martensite, make TRIP steels
6、desirable for increased load bearing capability, better crash energy management, and for part mass reduction through a decrease in sheet metal thickness (gauge). Note: Materials defined by these specifications exhibit bake hardening characteristics. Para 3.5.2 defines mechanical property requirement
7、s for tensile specimens which have been strained and baked prior to testing. Note: Because of regional supply base variations and to make the most effective use of these specifications, users should consult with Materials Engineering. Note: Commercially available precoated versions of these material
8、s are unlikely to include hot dip coatings. Note: There are no approved North American suppliers for these materials at this time. Contact Don Jordan (313-248-6926, ) for further information. 3. REQUIREMENTS 3.1 STANDARD REQUIREMENTS FOR PRODUCTION MATERIALS Material suppliers and part producers mus
9、t conform to the Companys Standard Requirements For Production Materials (WSS-M99P1111-A). ENGINEERING MATERIAL SPECIFICATION WSS-M1A351-A1/A3 Page 2 of 8 Copyright 2013, Ford Global Technologies, Inc. 3.2 DIMENSIONS AND DIMENSIONAL TOLERANCES 3.2.1 Thickness and Thickness Tolerances (see para 4.5)
10、The thickness specified on the Engineering Drawing shall be a minimum. 3.3 OTHER DIMENSIONS, TOLERANCES AND ASSOCIATED ITEMS . These shall be defined by the relevant national standards (see para 4.6) . As appropriate to the relevant national standards, the title of this paragraph shall be interprete
11、d to include length, width, flatness, camber and mass. 3.4 CHEMICAL COMPOSITION (weight percent) (see para 4.7) The upper and lower limits of chemical composition of the controlled elements shall be established by the supplier and be included in the Control Plan. 3.5 MECHANICAL PROPERTIES (See also
12、para 4.12) (Longitudinal Tensile Specimens)(50 mm Gauge Length) (ISO 6892/ASTM E 8M/EN 10002/JIS G 3135/JFS A 2001) (Note: Certain gauge (thickness) limitations apply) 3.5.1 As Received Variant A1 A2 A3 Yield Strength (0.2 % offset) (MPa min) 360 390 420 (MPa max) 460 490 520 Tensile Strength (MPa m
13、in) 600 700 800 *Elongation (% min) 28 26 24 *A gauge length (GL) of 80 mm may be used for control purposes, with appropriate (multiplication factor of 1.10 (80 mm GL to 50 mm GL) correction in % Elongation. In all cases, 50 mm will be considered the referee standard gauge length. When the gauge (th
14、ickness) is less than or equal to 0.70 mm, the minimum value for the % Elongation is reduced by 2 units. ENGINEERING MATERIAL SPECIFICATION WSS-M1A351-A1/A3 Page 3 of 8 Copyright 2013, Ford Global Technologies, Inc. 3.5.2 After 2% Pre-strain and 170 C for 20 Minutes Variant A1 A2 A3 Yield Strength (
15、0.2 % offset) (MPa min) 480 520 560 The bake (170 C for 20 minutes) portion shall contribute a minimum of 30 MPa to the yield strength increase. 3.6 FORMABILITY The quality level of steel supplied to fabricate a specific component shall be negotiated between the manufacturing activity and the steel
16、supplier. Steel internal cleanliness may involve the use of a mutually agreed referee method (see para 4.8). Acceptance of subsequent orders by the steel supplier for a given component at the agreed upon quality level implies that all steel supplied will be of a comparable quality level and will for
17、m that part satisfactorily as defined by the manufacturing activity. The company may, at its option and in agreement with the steel supplier, compile a list (known as the Sheet Metal Requirements List (SMRL) of property requirements such as mechanical properties, forming characteristics and surface
18、texture, for each specific part. If invoked, this list will be a mandatory extension of these specifications (see para 4.10). 3.7 WELDABILITY It is anticipated that the Carbon Equivalent (C.E.) of the material will always exceed 0.21%. Accordingly, to demonstrate acceptable weldability as part of th
19、e source approval process (see WSS-M99P1111-A, paragraph 4): A suitable spot welding technique and the number of spot welds to be tested shall be agreed between the Material Supplier and the relevant company Activity, prior to the commencement of the source approval process. This agreed technique sh
20、all consistently produce spot welds which never experience any interfacial failure when tested in cross tension*, regardless of the material gauge (thickness) or the strain rate. No cracks leading to failure in cross tension testing shall be present after welding*. The aforementioned spot welding te
21、chnique and associated parameters shall form part of the Approved Source List (ASL) entry for Ford (or a database nominated by the relevant company activity) and should be established at the time of ordering the material. C.E. is defined as %C + %Mn/6 + %(Cr + Mo + V)/5 + %(Ni + Cu)/15 *Note: Testin
22、g in peel or shear would sometimes be expected to result in a degree of interfacial failure. *Note: Prior to cross tension testing, the welds shall be optically examined at a magnification of X20. The position of any such cracks shall be marked to assist in the assessment of the cross tension testin
23、g. In the case of dispute as to the existence of a crack, metallographic sectioning and optical microscopy at a magnification of X200, shall be the umpire method. ENGINEERING MATERIAL SPECIFICATION WSS-M1A351-A1/A3 Page 4 of 8 Copyright 2013, Ford Global Technologies, Inc. 3.8 SURFACE FINISH AND APP
24、EARANCE Some applications will require the surface appearance to be defined as Class 1, Class 2, or Class 3 as appropriate: . A Class 1 surface shall be specified for parts of the vehicle that are exposed to view after paint or trim. . A Class 2 surface shall be specified for parts of the vehicle no
25、t covered by trim materials but exposed to view when the doors or enclosure lids are in an open position. . A Class 3 surface shall be specified for parts of the vehicle that are concealed during normal use. Unless otherwise specified via the Engineering Drawing, the SMRL (see para 3.6) or Purchase
26、(Supply), these materials shall be coated with a light, even film of protective, company approved mill oil (rust preventative oil) or prelube. (See also para 4.9) 3.9 PAINTABILITY Material supplied to these specifications must have prior approval for paintability by the responsible activity. This ap
27、proval shall be based on samples prepared to local process and performance requirements. (See para 4.11) 4. GENERAL INFORMATION The information given below is provided for clarification and assistance in meeting the requirements of these specifications. 4.1 DOCUMENT ORIGIN This document was original
28、ly compiled as a collaborative effort between Ford Europe, Mazda (Mazda Motor Corporation) and Ford Australia. 4.2 INITIAL SUPPLIER APPROVAL BY FORD (UNCOATED ONLY - For information for coated TRIP steel submissions see WSS-M1P94-A) For initial approval, the supplier should furnish the following inf
29、ormation for each variant: . A plan detailing how each requirement of para 3 will be controlled on a continuing basis. ENGINEERING MATERIAL SPECIFICATION WSS-M1A351-A1/A3 Page 5 of 8 Copyright 2013, Ford Global Technologies, Inc. . Test results from a typical production sample for the requirements o
30、utlined in para 3, with the exception that paintability testing should be conducted on one sample. . The intent of para 3.7 is that the Material Supplier should assess material that aims towards the highest chemistry and thinnest gauge (i.e. the most difficult material to spot weld) for any given gr
31、ade. . Mechanical property histograms including mean and standard deviation values. Data should consist of a minimum of 40 measurements for each property in para 3.5, taken from a minimum of 20 coils, while the process is operating in statistical control. Upon approval, the materials will be added t
32、o the Engineering Material Approved Source List. 4.3 MATERIAL USAGE For materials with a specified thickness below 1.80 mm, (see paras 3.2 1 micrometer (+/- 0.5 micrometer) band width; 12.5 mm min effective traverse length; flat skid type) is defined thus: . Class 1 (also known as B (EN 10130) or fu
33、ll finish (FF); Ra 1.1 - 1.6 (2.5 mm cut-off). Peak Density 45 ppcm (peak valley pairs per centimeter) min. . Class 2 (also known as A (EN 10130) or General Purpose (GP): Ra 1.1 - 1.7 Peak Density not defined. . Class 3 Ra and Peak Density not defined. 4.9.3 North American Guidance Refer to the Adva
34、nced Technology and Material Engineering (AT Materials Engineering and Testing. The current responsible area for the SMRL (within Jaguar) is Materials Engineering. The current responsible area for the SMRL (within Volvo Car Corporation (VCC) is Research, Development also the coating(s), as defined by WSS-M1P94-A. e.g. Steel, Sheet, Cold Rolled, TRIP, electrolytic zinc coated, minimum yield strength 360 MPa, minimum tensile strength 600 MPa, for a non-visible component, would be specified thus: WSS-M1A351-A1: Class 3 Coated to WSS-M1P94-A, 50G50G-EL
