The Next Generation of Advanced High Strength Steels .../media/Files/Autosteel/Great Designs in Steel... · w w w . a u t o s t e e l . o r g The Next Generation of Advanced High

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The Next Generation of Advanced High Strength Steels

– Computation, Product Design and Performance

First-Year Progress Update on the DOE ICME 3GAHSS Project

Louis G. Hector, Jr., Technical Fellow

General Motors R&D, Warren, MI 48316

Ron Krupitzer, Vice President

Steel Market Development Institute

2000 Town Center, Suite 320

Southfield, MI 48075-1123


Award to USAMP through Sec. Chu’s Office (DOE): February, 2013

• http://energy.gov/articles/energy-department-investments-develop-lighter-stronger-

materials-greater-vehicle-fuel

DOE Funding: $8,571,253 ($6,000,000 DOE funding (70%), $2,571,253 industry funding)

Duration: Four Years (February 1, 2013 – January 31, 2017)

Approach: Integrated Computational Materials Engineering + 3GAHSS Alloy Development

New ICME Project on Third Generation

Advanced High Strength Steels (3GAHSS)

Recipients, Sub-recipients, and Key Contractors

• USAMP: Chrysler, Ford, General Motors

• A/SP and SMDI: AK Steel, ArcelorMittal, Nucor Steel, Severstal

North America, and US Steel Corporation

• Universities: Brown University, Clemson University, Colorado

School of Mines, Michigan State University, University of Illinois

• National Lab: PNNL

• Engineering Companies: EDAG, LSTC


Candidate Automotive Components

for ICME 3GAHSS Project E

lon

ga

tio

n (

%)

Tensile Strength (MPa)

Current Materials

Gen 3 Steel Targets

Weight Reduction

(Gage and/or

Geometry)

Rails

DOE Steel Targets


(a) …use computers (with minimal experimental

inputs) to “design” multi-phase steel

microstructures that achieve desired strength

and ductility targets (for example).

(b) …generate constitutive models that accurately account

for the multi-scale physical phenomena in an advanced steel

under an arbitrary strain path.

(c) …pass models onto metal forming and CAE engineers

for formability and performance predictions in commercial FE codes. (d) …predict formability and failure

limits.

ICME Constitutive Model Development for

3GAHSS


LP

Start with

QP980

ST 2.1 Experimental:

Nanometric to Grain

Scale Mechanical

Tests/Texture (EBSD)

(years 1-4)


Coupon-Level Tests for

Flow Behavior,

Formability, Failure

Fracture (years 1-4)

ST 2.8 Computational:

Microstructural Design

and Analysis of

3GAHSS

(years 1-2)

ST 2.3 Computational :

Atomistics for

Defects/Strengthening/

Hardening (years 1-4)


Crystal Plasticity

For Mechanical

Properties of Phases in

Microstructure (years

1-4)

ST 2.9 Experimental

Design and

Manufacture of

3GAHSS (years 1-4)

ST 2.5 Evolutionary

Yield Function

(years 1-4)


Microstructure-Based

Finite Element

Approach for Bulk

Sheet YS, UTS, TE, UE

and Formability (years

1-4)


Development and

Validation of Macroscopic

Constitutive Models for

Deformation and Fracture

-PamStamp,\LS-DYNA,

ABAQUS (years2-4)


Failure/Fracture

Models

(years 3-4)

Phase II Integration,

design, cost analysis,

and model and

property database with

3GAHSS

Task 2 - ICME Constitutive Model

Development Path for 3GAHSS

Brown

Brown

CSM

Michigan State UIUC Michigan State

Clemson

PNNL

PNNL + A/SP

A/SP


Experimental: Nanometric to Grain Scale

Mechanical Tests/Texture (EBSD)

• Brown University, School of Engineering

– Prof. Sharvan Kumar

– Prof. Allan Bower

– Dr. Hassan Ghassemi-Armaki

– Dr. Hyokyung Sung

• Purpose:

– Measure flow properties of individual steel phases

with state-of-the-art micropillar compression

– Measure texture information with Electron Backscatter

Diffraction (EBSD); measure austenite transformation

kinetics.

• Integration:

– Provide experimental data for inputs to atomistic and

crystal plasticity (microstructural) simulations and

model validation.


Nanometric to Grain

Scale Mechanical

Tests/Texture


As Received

100 mm

As Received As Received

0.0 0.1 0.2 0.3 0.4 0.50

200

400

600

800

1000

Str

ess (

MP

a)

Strain

5%

10%

20%

30%

40%

50%

Fracture

Interrupted tests

10 % strain

201LN

Neutron diffraction

estimated values

AK steel corp.

Austenite

Martensit

e

Martensite

Evolution with

Strain in 201LN




Micropillar Deformation in As-Rec. Austenitic 201LN

Single Slip

System

436

316

124

0.00 0.01 0.02 0.03 0.04 0.050

200

400

600

800

1000

1200

Str

ess (

MP

a)

Strain

436

316

124

316

436 124

Multiple Slip

Systems

0.00 0.01 0.02 0.03 0.04 0.050

200

400

600

800

1000

1200

Str

ess (

MP

a)

Strain

003

033

113

115

113

115

003 033

003

033

115 225

113




Experimental: Coupon-level Tests for Flow

Behavior, Formability, Failure/Fracture

• Clemson University,

- Prof. Fadi Abu-Farha

• Purpose:

– Perform macro-scale measurements, including:

• Uniaxial tensile testing

• Hydraulic bulge test (balanced biaxial)

• Controlled biaxial testing (cruciform)

• Austenite-to-martensite transformation at different conditions

• Shear testing

• Formability testing -Nakajima/Marciniak

• Tension-compression testing

• Edge fracture (hole expansion test, center hole specimen tension

test)

• Other (draw bend / stretch bending test, springback, etc.)

• Integration:

– Provide experimental data for input to and crystal plasticity

(microstructural) simulations and homogenized

constitutive model validation.


Coupon-Level Tests for

Flow Behavior,

Formability, Failure

Fracture


Digital Image Correlation Simple Tension of Q&P980 (@45o, 23oC) Stationary color bands appear on the tensile bar surface.


Digital Image

Correlation

Formability

test of Q&P

980 steel

stretching with

a cylindrical

punch @ 23oC.


Computational: Atomistics for

Defects/Strengthening/Hardening

• University of Illinois

– Prof. Dallas Trinkle

– Dr. Michael Fellinger

• Purpose:

– Using electronic structure methods, compute

material properties, elastic constants, hardening

parameters of 3GAHSS phases/chemistry.

– Compute dislocation core structures, then

energetics of core/solute interactions for e.g.

Critical Resolve Shear Stress (CRSS), and

(possibly) other hardening parameters.

• Integration:

– Provide computed inputs to crystal plasticity

modeling effort to reduce number of experimental

inputs; reduce dependencies upon data fitting.


Atomistics for Defects

/ Strengthening /

Hardening




Stacking-fault energy surfaces: bcc {110} and {112}, and fcc {111}




Energy (eV)

FCC

BCC

Volume

Bain path

calculations

including C are

in progress

Screw dislocations in bcc Fe: Initial geometry and force-constant calculations

Bain transformation from fcc to bcc


Computational: Crystal Plasticity for Mechanical

Properties of Phases in Microstructure

• Michigan State University

– Prof. Farhang Pourboghrat

• Purpose:

– Generate and then mesh a realistic 3D RVE

of 3GAHSS for use in crystal plasticity

simulations.

– Develop evolutionary yield function for FE

simulations.

• Integration:

– Apply Brown-measured data to facilitate

crystal plasticity simulations. ST 2.1 Computational:

Crystal Plasticity for

Mechanical Properties of

Phases in Microstructure




Using Brown University Generated Microstructural Data

to Generate a 3D Representative Volume Element (RVE)

or





Computational: Microstructural Design

and Analysis of 3GAHSS

• Colorado School of Mines

– Professor David Matlock

– Professor John Speer

• Purpose:

– Develop recipes for 3GAHSS that meet

DOE targets for mechanical properties,

mass and cost savings.

• Integration:

– Provide recipes to make 3GAHSS coupons.


Microstructural Design



Exceptional Strength Targets - High Ductility 1500 MPa/25% TE

• Steel Type: Quenching and partitioning (Q&P) steel

• Processing:

• Austenite: 820 °C, 2 min.

• Quench: 180 °C

• Partition: 400 °C, 100 s

Example: SEM of Q&P steel 0.3C–3Mn–1.6Si

sample austenitized at 820°C for 120 s, quenched

to 200°C, and partitioned at 400°C for 30 s.

E. De Moor, J.G. Speer, D.K. Matlock, J.H. Kwak, and S.B. Lee, “Effect of Carbon and Manganese on the

Quenching and Partitioning Response of CMnSi Steels,” ISIJ Intl. Vol. 51, no. 1, 2011, pp.137-144.



Under development


• Steel Type: Medium Mn, Duplex TRIP steel

• Processing:

Intercritical anneal: 600 °C, 96 h

Reversion anneal: 640 °C, 16 h

High Strength - Exceptional Ductility Targets: 1200 MPa/30% TE

Example: SEM of Medium Mn (7.1-Mn) steel

annealed for 168 hr. at 600 °C followed by water

quenching – selected to illustrate features

anticipated in10-Mn microstructure

P. J. Gibbs: “Design considerations for the third generation advanced high strength steels”, Ph.D Thesis,

Colorado School of Mines, 2013



Under development


Design and Manufacture of 3GAHSS Steel Sheets

• To validate length scale material models, 3GAHSS

heats are being made and rolled.

– AK Steel used CSM recipes to cast two heats which are

being processed into sheet.

– Mechanical property test results and microstructural

analysis will be used to validate the material models

• Refined and validated models will eventually be

used to predict 3GAHSS chemistry and

microstructure with mechanical properties that

meet the DOE 3GAHSS targets

AK Steel 3GAHSS Heat

ST 2.9 Design and

Manufacture of 3GAHSS

Steel Sheets

• Auto/Steel Partnership


Task 3: Forming – Component-Scale

Performance Prediction and Validation


• Purpose:

– To identify applicable forming models and

validate these models using component-

scale forming trials.

• Integration:

– Integration of forming models with the

length scale material models of Task 2 and

Task 5 design optimization.

– Use of 3GAHSS heats from Sub-Task 2.9

for forming and performance model

validation Task 3: Forming –

Component-Scale

Performance Prediction

and Validation

Images courtesy of Severstal.

Hardening Yield FLD


Task 3: Forming – Component-Scale

Performance Prediction and Validation

• Forming simulations: begin with the BAO QP980 steel

and then progress to 3GAHSS from Sub-Task 2.9.

• Outputs to the forming simulation: to be compared to

forming trials with components such as a T-shaped

and/or U-bend component.

• The validated models will be integrated with the length

scale material models from Task 2 and the Task 5

Design Optimization

Draw stretch sample

Stretch bend sample

Image courtesy of

Severstal.

Image courtesy of ArcelorMittal

R&D East Chicago.


Task 4 ‘Assembly’ and Task 6 ‘Integration’

• Livermore Software And Technology

Corporation


• Purpose:

– Task 4: To assemble validated length scale

material models sufficient to predict

3GAHSS chemistry and microstructures that

can meet the DOE FOA target mechanical

properties.

– Task 6: To integrate the length scale

material models with forming models,

performance models, design optimization

and technical cost modeling into the ICME

model.

Task 4 ‘Assembly’ and

Task 6 ‘Integration’


Status: Task 5 ‘Design Optimization’ and

Task 7 ‘Technical Cost Modeling’’

• EDAG Corporation


• Purpose:

– Task 5: To optimize a baseline assembly

consisting of four or more AHSS components

using 3GAHSS mechanical properties

– Task 7: To develop a technical cost model that

includes material and manufacturing costs.

• Integration

– Design optimization will be coupled with forming

and performance simulations from Task 3

• Determine the feasible 3GAHSS gauges and

shapes for weight optimized assembly.

Task 5 ‘Design

Optimization’ and

Task 7 ‘Technical Cost

Modeling’’


Status: Task 5 ‘Design Optimization’ and

Task 7 ‘Technical Cost Modeling’’

• The baseline assembly is the body structure of a

four-door, mid-size sedan.

– Bill of materials (alloys and grades) - Complete

– Component and assembly weights - Complete

– Load cases have been defined

• Side barrier impact

• Pole impact

• Roof crush

• Front impact

• Rear impact

• Seat belt anchorage strength

– Currently assessing baseline assembly

performance against defined load cases

– Design optimization with 3GAHSS will begin

with the completion of the baseline assembly

performance assessment.

• Preliminary Technical Cost Model - Complete

Body Structure: Baseline Mid-Size sedan


“The Endgame”

Task 2.


Acknowledgement

This material is based upon work supported by the Department of Energy National Energy Technology Laboratory under Award Number No. DE-EE0005976.

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Such support does not constitute an endorsement by the Department of Energy of the work or the views expressed herein.


Thank You For Your Attention!

Questions?

“…one cannot be but

impressed by the potentialities

of an implement of research so

fine-grained that it reveals the mode

of association of the atoms themselves.”

Edgar Bain, United States Steel Corp. (ca. 1920s)


North American

Light Vehicle Metallic Material Trends

Great Designs in Steel is Sponsored by:

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The Next Generation of Advanced High Strength Steels .../media/Files/Autosteel/Great Designs in Steel... · w w w . a u t o s t e e l . o r g The Next Generation of Advanced High