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Project Fact Sheet 
SERVICE PERFORMANCE OF WELDED DUPLEX 
BENEFITS 
APPLICATIONS
STAINLESS STEEL CASTINGS 
This project will develop a suitable database 
to provide detailed fabrication and service 
performance guidelines including welding and 
heat treatment procedures for duplex 
stainless steel and wrought materials. 
The database will enable the industry to 
reduce wastes resulting from improper 
fabrication and heat treatment methods, to 
reduce fabrication time due to undocumented 
fabrication procedures, and to improve 
service performance of components 
fabricated from duplex stainless steels, 
compared to conventional materials. 
Energy savings will result from the reduced 
need to produce replacement castings. In 
addition, foundry customers will realize 
substantial energy and cost savings due to 
reduced shutdowns for maintenance. 
These results can be applied throughout the 
steel foundry industry. Moreover, a variety 
of types of industrial facilities can benefit from 
enhanced duplex stainless steel castings and 
wrought materials. Examples include: oil 
refineries, ethylene furnaces, and reformer 
furnaces. There are about 187 oil refineries 
in the U.S. and an estimated 450 ethylene 
furnaces and 700 reformer furnaces in the 
U.S. 
DETERMINING THE EFFECTS OF WELDING ON CORROSION PERFORMANCE 
OF CAST AND WROUGHT DUPLEX STAINLESS STEEL 
Welding can impair the corrosion performance of both wrought and cast materials. 
It requires that both the fabrication aspects of the materials and the published 
values for the base materials be taken into account. 
The corrosion performance is most egregiously degraded by welding processes 
which leave behind a fusion zone containing melted base material. This melted 
base metal zone, which is termed the “unmixed zone” in the filler metal added 
processes, is the region responsible for the degraded corrosion pitting resistance. 
Further, the phase balance in this zone is influenced by solidification and this 
phase balance must be restored either by heat treatment or by the selection of 
filler metals richer in austenite formers such as nickel and nitrogen. 
A paucity of data exists upon which the specifier/engineer can base service 
performance. Hence, the industry needs a more comprehensive study of the 
behavior of welded components. This project, lead by the University of Tennessee 
and sponsored by the Steel Founders' Society of America will document the 
effects of welding on duplex stainless steel castings and provide guidelines to 
casting and design engineers to aid in the selection of materials. 
CORROSION PERFORMANCE MAY BE DEGRADED UPON WELDING 
Weld fusion boundary pitting corrosion sensitive material ASTM A890-4A 
(2205 type). 
OFFICE OF INDUSTRIAL TECHNOLOGIES 
ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY
Showcase Description 
Goal: The goal of this project is to examine and determine the effects of welding 
on the corrosion performance of cast and wrought duplex stainless steel materials. 
The results will be presented in the form of guidelines to engineers in the selection 
of materials. 
Progress and Milestones 
This three year project was awarded in August 2000. Planned activities include: 
• Determine the proper filler metals to be utilized for the upgrading of casting which 
will be solution heat treated prior to fabrication and service. 
• Determine the optimum filler metals for use when the structure is to be utilized in the 
as-welded condition. 
• Define the phase balance for all conditions utilizing appropriate "ferrite" measuring 
techniques. 
PROJECT PARTNERS 
University of Tennessee 
Knoxville, TN 
Steel Founders' Society of America 
Barrington,IL 
Alloy Rods 
Champaign, IL 
Atlas Foundry and Machine 
Tacoma, WA 
Keokuk Steel Casting 
Keokuk, IA 
Quaker Alloy 
Myerstown, PA 
Welding Research Council 
New York, NY 
Wollaston Alloys 
Braintree, MA 
FOR ADDITIONAL INFORMATION, 
PLEASE CONTACT: 
Harvey Wong 
Office of Industrial Technologies 
Phone: (202) 586-9235 
Fax: (202) 586-6507 
Harvey.Wong@ee.doe.gov 
http://www.oit.doe.gov/IOF/metalcast/ 
Please send any comments, 
questions, or suggestions to 
webmaster.oit@ee.doe.gov. 
Visit our home page at 
www.oit.doe.gov 
Office of Industrial Technologies 
Energy Efficiency 
and Renewable Energy 
U.S. Department of Energy 
Washington, D.C. 20585 
December 2000