September 06, 2023
Nippon Yakin Kogyo Co., Ltd.

Nippon Yakin Kogyo Co., Ltd. and Osaka University Joint Research Paper
Receives Best Paper Award from the International Institute of Welding
Nippon Yakin Kogyo joint research paper with Osaka University has received the 2022 Best
Paper Award from the International Institute of Welding. The award ceremony was held at
the Marina Bay Sands Convention Center in Singapore on July 16-21, 2023 at the 76th
Annual Conference of the International Institute of Welding. A researcher of our TechnicalResearch Center attended with collaborators of Osaka University.
1． Title of the award-winning paper
Relationship between ferrite–austenite phase transformation and precipitation behaviorof sigma phase in super duplex stainless steel weldment
Welding in the World, vol.66 (2022), No.2, pp.351-362.
2． Authors■ Nippon Yakin Kogyo Co., Ltd.
Fu-Gao Wei (Technical Research Center), Kun Wang (Senior Managing Executive
Officer)■ Graduate School of Osaka University, Division of Materials and Manufacturing
Science, Manufacturing Science Course
Processing for Manufacturing, Materials Joining Process Area (Saida Laboratory)
Shotaro Yamashita, Kazuyuki Ike, Kazuma Yamasaki, Tomo Ogura, Kazuyoshi Saida(titles omitted)
3． Abstract
We developed NAS74NU super duplex stainless steel with excellent corrosion
resistance and mechanical properties. It is generally difficult to weld the super duplex
stainless steels. It has been problematic that welding leads to a decrease in corrosion
resistance and brittleness at weld.
In this paper, we have revealed for the first time our metallographic mechanism forsustaining superior corrosion resistance and mechanical properties even after
NAS74NU is welded. We were consequently awarded by recognized that our super
duplex stainless steel NAS74NU has excellent weldability maintaining corrosion
resistance.
As stated in the list of authors above, this paper is the product of joint research
conducted with the Graduate School of Osaka University, Division of Materials andManufacturing Science, Manufacturing Science Course, Processing for Manufacturing,
Materials Joining Process Area (Saida Laboratory). We will continue to actively pursue
joint research with universities and other research institutions for the development of
cutting-edge technologies.

At the award ceremony (Our TechnicalBest Paper Award Certificate

Research Center, Fu-Gao Wei)
【Reference】
About the International Institute of Welding and the Best Paper Award
Comprised of about 50 member nations, the International Institute of Welding is the world’s largest
international organization for welding. The Best Paper Award is conferred upon the person(s)found by the Institute to have published the previous year’s most scientifically and technologicallysignificant paper amongst those printed in “Welding in the World”, the academic journal issued by
the Institute. One paper is selected from each of three categories (A, B and C). We received theaward in Category B.
Category A： Welding Processes and Additive Manufacturing
Category B： Materials and Metallurgy
Category C： Structural Integrity, Design and Fitness or Service

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