Toughening ultrastrong low-density steel by textured δ-ferrite lamellas  

作　　者：Bin Hu Guosen Zhu Guohui Shen Zheng Wang Qinghua Wen Xiao Shen Haiwen Luo 

机构地区：[1]School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Xue Yuan Rd.30,Beijing 100083,China [2]Shougang Research Institute of Technology,Yangzhuang Street 69,Beijing 100043,China [3]Steel Institute,RWTH Aachen University,Intzestraße 1,52072,Aachen,Germany

出　　处：《Defence Technology（防务技术）》2024年第2期405-411,共7页Defence Technology

基　　金：financial support from National Natural Science Foundation of China(Grant Nos.51831002,51904028 and 52233018),China;Fundamental Research Funds for the Central Universities(Grant No.06500151),China.

摘　　要：By both the Charpy V-notched impact and the projectile tests, we here investigated the dynamic fracture behavior of a recently developed ultrastrong lightweight steel comprising a hierarchical martensitic matrix, dispersed ultra-fine-retained austenite grains and oriented δ-ferrite lamellas, the latter being due to high Al and Si contents employed for low-density design. This steel shows a superior combination of specific ultimate tensile strength and impact toughness to other ultrastrong steels and has successfully arrested a real steel-cored bullet shot. These are attributed to the densely textured δ-ferrite lamellas that can deflect the propagating cracks until they are trapped and enclosed besides austenite-to-martensite transformation crack closure, leading to more energy consumed before failure. These results suggest a new pathway for toughening ultrastrong lightweight steels.

关 键 词：Ultrastrong and light steel d-Ferrite lamellas Crack propagation TOUGHNESS 

分 类 号：TG142.1[一般工业技术—材料科学与工程]