SAE J2947 and VDA 239-100:

Global Sheet Steel Specifications

Alan Darrell Pearson

SAE Metals Technical Committee Chairman

SAE Sheet and Strip Committee Chairman

SAE Standards

In discharging their responsibilities, members of the

Technical Standards Board, Councils/Division, and

Technical Committees function as individuals and not

as agents or representatives of any organization with

which they may be associated, except that

government employees participate in accordance

with governmental regulations. Members are

appointed to SAE Technical Committees on the basis

of their individual qualifications which enable them to

contribute to the work of the Committee.

Great Designs in Steel 1968

Great Designs in Steel 2016

Camaro Wheel Studs

• Left or right hand thread

• Tapered seat

• SAE J429 7/16-20 steel stud

• SAE J1102 M14x1.5 steel stud

• Wheel locks

Which are on the 1st Gen…or on the 6th Gen?

Standardization Methodology

• Regional Standards for sheet steel have historically

been used with restrictions at OEM’s and Tier 1’s

− SAE (Society of Automotive Engineers) - USA

− EN (Euronorm) - Europe

− JIS (Japanese Industrial Standards) - Asia

• These have been the main regional specification

bodies and test methods for auto sheet metal

• Each region developed standards based on

specific tensile test sample geometry

21st Century North American Historical Perspective

• Automotive OEM’s company specs contain specific

product and manufacturing requirements

• SAE Sheet and Strip Committee publishes:

− J2329 Low Carbon Sheet Steels 5/97

− J2340 Dent Resistant, Structural and HSLA

10/99

− J2745 Advanced High Strength Steels 7/07

− J2947 Steel Sheet for Automotive Cold Forming

Applications 2016

Need for Global Specifications

• Vehicles are designed by global companies to sell

in global markets

• Sheet steel is a critical structural material for the

body in white (BIW) and chassis

• Availability of specific steel grades is needed in all

regions to successfully manufacture vehicles to the

original design intent

• Property variation of grades can influence success

of stamping and assembly operations and vehicle

quality

The Working Group

• Verband der Automobilindustrie (VDA) - The

German Association of the Automotive Industry

begins a working group to write an all

encompassing cold forming sheet steel

specification for the automotive industry in 2009

• SAE Sheet and Strip committee begins an informal

collaboration with the working group in 2010 to

encompass European and North American users

and producers of sheet steel for automobiles

• Discussions revolve around the VDA 239-100 draft

Results

• Both VDA and SAE are voluntary organizations for

standardization. Specifications are written to

advance usage of materials (STEEL!) for the

common good. SAE members represent

themselves as technical experts in the field

• Rules were developed by the working group to

make recommendations and agree on ranges of

properties based on available industry data

• VDA 239-100 published in 2011

2010-11 Workgroup Issues

• Test methods were determined to be a critical

issue in determination of properties

• ASTM (ISO Type 1) and DIN (ISO Type 2) elongation

numbers were included to allow both test methods

• Longitudinal and transverse test orientation

influence on properties, anisotropy issues on

certain high strength grades

• Bake hardening requirements for all high strength

grades, with different test methodology in North

America and Europe – Task Team created in 2011

Bake Hardening Task Team Questions

• Test parameters:

− Upper or lower yield point measurement

− Remeasure after prestrain...or not

− Do we include zinc coating in the thickness measurement ?

• Bake Hardening (BH) increment specification requirement of 20 or 30 MPa

increase cannot be agreed until all testing is done in a standard manner.

• From the same typical stress strain curve, both requirements can be met using

combinations of the 3 different test parameters.

• Continuous Anneal (CA) typically has higher BH index than Batch Anneal (BA)

product.

• As mills do not check every coil for certification, very wide spread actual tensile

test measurements drive incapable 3 sigma.

• CA instead of BA production in Europe and globally causes different aging

requirements and inventory management methods.

…and more questions

1) Dual Phase (DP) structural usage and Bake Hardenable (BH) dent resistance for

exposed panels drive different test method requirements/opinions. Do we have

options for the index?

1) Lower yield point for crash deformation

2) Upper yield point for dent resistance

2) With current FEA analysis techniques, is the absolute requirement needed?

3) Do the vehicle OEM’s need the 20/30 BH increment used in part design?

4) Can OEM’s use source approval for review of upper/lower calculated data and

acceptance of the grade recipe?

5) Bake Hardening (BH) index cannot be measured on the final part after forming,

mixes with Strain Hardening…do we need a different measure (BH +SH = part

strength increase)?

6) Do we only need +/-2 sigma capability (95% confidence level) for this spec

requirement?

The 3 C’s of Writing Standards

Collaboration

Cooperation

Compromise

Compromise

• Team recommendation as result of vote (not unanimous)

• Test parameters to use:

− Lower yield point measurement - remeasure after prestrain - include zinc coating (if any)

• Specification requirement of 20 or 30 MPa increase cannot be agreed until testing is done in a

standard manner; CA vs BA differences, aging, inventory management.

• From the same typical stress strain curve, both requirements can be met using the different test

parameters; use standard test, interpret data in spec requirement.

• Mills do not check every coil for certification. Do we only need +/-2 sigma capability for this spec

requirement? The spread on actual measurements is very wide.

• Product needs:

• Dual Phase structural use and dent resistance for exposed panels drive different test method

requirements/opinions:

− Low yield point or 0.2% offset for crash deformation - High yield point for dent resistance.

• With current FEA analysis techniques, is the absolute requirement needed? What do the vehicle

OEM’s need? Is the increment used in part design?

• Bake Hardening (BH) index cannot be measured on the final part after forming, Do we need a

different measure (BH +SH = part strength increase) ?

J2947 Cold Rolled Grades

Steel Description Grade Type Available Strength Grade – MPa

Mild Steels Low

Carbon

CR grades 1 through 5

Bake-Hardenable BH 180, 210, 240, 270, 300

High Strength Interstitial Free IF 180, 210, 240

High Strength Low Alloy LA 210, 240, 270, 300, 340, 380, 420, 500

Dual Phase(1) DP 490, 590, 690, 780, 980

Transformation Induced Plasticity

(TRIP)(1)

TR 590, 690, 780

Complex Phase(1) CP 780, 980, 1180

Martensitic(1) MS 900, 1100, 1300, 1500, 1700

1. For this grade classification, the strength grade is referenced by minimum tensile

strength instead of minimum yield strength.

TABLE 1 – COLD ROLL STEELS AND STRENGTH GRADES

J2947 Hot Rolled Grades

Steel Description Grade Type Available Strength Grade – MPa

Mild Steels Low

Carbon

Grades 0, 1, 2

High Strength Low Alloy LA 270, 300, 340, 380, 420, 460, 500, 550,

700

Dual Phase(1) DP 580

Ferrite - Bainite(1) FB 450, 580, 780

Complex Phase(1) CP 780, 980

1. For this grade classification, the strength grade is referenced by minimum tensile

strength instead of minimum yield strength.

TABLE 2 – HOT ROLL STEELS AND STRENGTH GRADES

Future Work

• The working group continues to define the 2.5 and 3.0

Generation steel grades.

• Work needed with global standard associations and groups

to get input and data, define property ranges and types of

testing methods.

• Example: China Metallurgical Standardization Research

Institute (CMSI) preliminary discussions.

• Further data and technical input on Galvanneal and Zinc-

Aluminum-Magnesium coated steels.

• Work on Release 2 of VDA239-100 and potential additions

to J2947continue.

Engagement Needed

I need technical experts from global users and global

producers to become part of the SAE International

Sheet and Strip Committee

Global collaboration, cooperation, and compromise

thru voluntary standardization bodies are needed to

achieve a true global specification

#GDIS

Presentations will be available May 16

at www.autosteel.org