ALUMINUM 
Project Fact Sheet 
ROLLING PROCESS DESIGN TOOL 
BENEFITS 
The potential benefits to the domestic 
aluminum industry assuming a 10 percent 
increase in hot roll yield: 
ï Annual cost savings to the domestic 
aluminum industry of $105 million 
ï Annual manufacturing energy savings up 
to 12 trillion Btu 
APPLICATIONS 
One of the principal forming processes for 
aluminum is the hot rolling of ingot into thick 
slabs and further rolling to form plate and 
sheet material of various thickness. 
Approximately 45 percent of produced 
aluminum ingot material passes through this 
process. This project's new technology 
could improve the competitive position of the 
domestic aluminum industry in the 
transportation, packaging, building and 
construction, and other industries. 
DEVELOPMENT OF A ROLLING PROCESS DESIGN TOOL FOR USE IN 
IMPROVING HOT ROLL SLAB YIELD 
Multiple passes in a reversing rolling mill of a hot slab are used to produce semifinished 
aluminum plate. However, the large deformations encountered while 
rolling may lead to failure modes that result in loss of part or even all of the slab. 
The formation of defects within the plate, such as edge cracking, delamination, 
alligatoring (center splitting near the front and rear), and the formation of 
undesirable rolled end shapes, all lead to product losses. Critical equipment 
downtime is also associated with several failure modes. Typically, rolling plant 
yield from ingot to final production is about 50 percent. Rejected material is 
recycled and melted to form new ingots. Improving yield would lower the overall 
energy used in processing aluminum. 
Processing parameters could be chosen that minimize loss of product and 
significant improvements in energy efficiency could be attained if the slab material 
response to the hot rolling process was sufficiently well understood. Currently, 
processing parameters are optimized by trial and error or from empirical evidence. 
Project partners will develop a rolling process design tool for use in improving hot 
roll slab yield. Numerical simulation of the full thermal-mechanical process will 
play a major role in optimizing the process to increase product yield. The material 
forming experience and the numerical simulation capabilities developed from this 
project, can be used in other aluminum-forming processes and will provide 
significant energy benefits. 
FINITE ELEMENT MODELS 
A finite element model representing rolls, slab, and supports is illustrated. The 
rolling tool model will include formulae of material properties, structural response, 
friction, and heat transfer. 
OFFICE OF INDUSTRIAL TECHNOLOGIES 
ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY
Project Description 
Goal: The project goal is to develop a numerical modeling capability to optimize 
the hot rolling process used to produce aluminum plate. This tool will be used in 
the forming process so that loss of product will be minimized. Product lost in the 
rolling process requires the energy-intensive steps of remelting and reforming into 
an ingot. The modeling capability developed by project partners will be used to 
produce plate more efficiently and with better properties. The major objectives in 
achieving the goal of this project are to: 
- predict temperature, stress, strain, strain rate history and damage 
evolution of slab material as it evolves through multi-pass rolling. 
- determine the effect of initial slab shape and rolling pass schedule on 
fracture and internal product integrity. 
- demonstrate the utility of a numerical model as a forming process 
optimization tool. 
Progress and Milestones 
• Determine material constitutive properties. Conduct uniaxial hot compression 
tests, model data and incorporate into slab modeling code. 
• Determine material fracture properties. Conduct uniaxial hot tension/ 
compression/torsion tests including directionality. Determine model constants 
and implement model in code. 
• Implement friction model. Incorporate state variable friction model in code. 
• Characterize the hot rolling process by determining boundary and initial 
conditions. Develop geometric configuration, heat transfer description and 
initial temperatures of slabs and rolls. 
• Produce rolling data for code validation. Characterize microstructure evolution 
and fracture initiation and growth. 
tensile fracture data. Produce initial and boundary conditions for rolling data 
• Validate finite element model. Compare to rolling data and to uniaxial hot 
validation studies. 
• Apply model to production rolling configuration. Define initial and boundary 
conditions. Produce finite element model and compare predicted material 
properties with observed properties. 
• Perform parameter studies by evaluating temperature distribution, roll speed, 
ingot geometry, pass schedule and roll gap geometry. 
Commercialization Plan 
The rolling process design experience developed by project partners will be made 
available to the aluminum community through journal publications and/or technical 
presentations. The Alcoa Technical Center will perform analysis of production 
environments at its rolling plants to produce better process design guidance for 
use at their plants. 
PROJECT PARTNERS 
Lawrence Livermore National Laboratory 
Livermore, CA 
Alcoa Incorporated 
Alcoa Center, PA 
FOR ADDITIONAL INFORMATION, 
PLEASE CONTACT: 
Project Information 
Dr. Richard Couch 
Lawrence Livermore National Laboratory 
Phone: (925) 422-1655 
Fax: (925) 422-3389 
couch1@llnl.gov 
Aluminum Program 
Simon Friedrich 
Office of Industrial Technologies 
Phone: (202) 586-6759 
Fax: (202) 586-1658 
simon.friedrich@ee.doe.gov 
Please send any comments, 
questions, or suggestions to 
webmaster.oit@ee.doe.gov. 
Visit our home page at 
www.oit.doe.gov/aluminum 
Office of Industrial Technologies 
Energy Efficiency 
and Renewable Energy 
U.S. Department of Energy 
Washington, D.C. 20585 
October 2001