Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels.
Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400-450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0-1.2 GPa at room temperature, which is nearly 3-5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry.
Special Steel department of Central Iron and Steel Research Institute (CISRI), Beijing 100081, China.
Wenquan
W
Cao
Special Steel department of Central Iron and Steel Research Institute (CISRI), Beijing 100081, China.
Mingda
M
Zhang
School of Aeronautics and Astronautics, Sichuan University, Chengdu 610065, China.
Chongxiang
C
Huang
School of Materials Science and Engineering, University of Science &Technology of Beijing, Beijing 100083, China.
Shuyang
S
Xiao
Special Steel department of Central Iron and Steel Research Institute (CISRI), Beijing 100081, China.
Han
H
Dong
Special Steel department of Central Iron and Steel Research Institute (CISRI), Beijing 100081, China.
Yuqing
Y
Weng