Abstract

Steel is the global backbone material of industrialized societies, with more than 1.8 billion tons produced per year. However, steel-containing structures decay due to corrosion, destroying annually 3.4% (2.5 trillion US$) of the global gross domestic product. Besides this huge loss in value, a solution to the corrosion problem at minimum environmental impact would also leverage enhanced product longevity, providing an immense contribution to sustainability. Here, we report a leap forward toward this aim through the development of a new family of low-density stainless steels with ultra-high strength (> 1 GPa) and high ductility (> 35%). The alloys are based on the Fe–(20–30)Mn–(11.5–12.0)Al–1.5C–5Cr (wt%) system and are strengthened by dispersions of nano-sized Fe3AlC-type κ-carbide. The alloying with Cr enhances the ductility without sacrificing strength, by suppressing the precipitation of κ-carbide and thus stabilizing the austenite matrix. The formation of a protective Al-rich oxide film on the surface lends the alloys outstanding resistance to pitting corrosion similar to ferritic stainless steels. The new alloy class has thus the potential to replace commercial stainless steels as it has much higher strength at similar formability, 17% lower mass density and lower environmental impact, qualifying it for demanding lightweight, corrosion resistant, high-strength structural parts.

Details

Title
A new class of lightweight, stainless steels with ultra-high strength and large ductility
Author
Moon Joonoh 1 ; Heon-Young, Ha 1 ; Kim, Kyeong-Won 1 ; Seong-Jun, Park 1 ; Tae-Ho, Lee 1 ; Sung-Dae, Kim 1 ; Jang, Jae Hoon 1 ; Hyo-Haeng, Jo 1 ; Hyun-Uk, Hong 2 ; Lee Bong Ho 3 ; Young-Joo, Lee 4 ; Lee, Changhee 5 ; Dong-Woo, Suh 6 ; Han Heung Nam 7 ; Raabe Dierk 8 ; Chang-Hoon, Lee 1 

 Korea Institute of Materials Science, Steel Department, Advanced Metals Division, Changwon, Republic of Korea (GRID:grid.410902.e) (ISNI:0000 0004 1770 8726) 
 Changwon National University, Department of Materials Science and Engineering, Changwon, Republic of Korea (GRID:grid.411214.3) (ISNI:0000 0001 0442 1951) 
 Daegu Gyeongbuk Institute of Science and Technology, Center for Core Research Facilities, Daegu, Republic of Korea (GRID:grid.417736.0) (ISNI:0000 0004 0438 6721) 
 Research Institute of Industrial Science and Technology, Advanced Metallic Materials Research Group, Pohang, Republic of Korea (GRID:grid.464658.d) (ISNI:0000 0001 0604 2189) 
 Hanyang University, Division of Materials Science and Engineering, Seoul, Republic of Korea (GRID:grid.49606.3d) (ISNI:0000 0001 1364 9317) 
 Pohang University of Science and Technology, Graduate Institute of Ferrous Technology, Gyeongbuk, Republic of Korea (GRID:grid.49100.3c) (ISNI:0000 0001 0742 4007) 
 Seoul National University, Department of Materials Science and Engineering and Research Institute of Advanced Materials, Seoul, Republic of Korea (GRID:grid.31501.36) (ISNI:0000 0004 0470 5905) 
 Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany (GRID:grid.13829.31) (ISNI:0000 0004 0491 378X) 
Publication year
2020
Publication date
2020
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2426015026
Copyright
© The Author(s) 2020. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.