Fracture behavior and mechanism of highly fragmented steel cylindrical shell under explosive loading

• Published in: Defence technology Vol. 36; no. 6; pp. 122 - 132
• Main Authors: Wang, Kang, Chen, Peng, Sun, Xingyun, Liu, Yufeng, Meng, Jiayu, Li, Xiaoyuan, Zheng, Xiongwei, Xiao, Chuan
• Format: Journal Article
• Language: English
• Published: Beijing Elsevier B.V 01.06.2024; KeAi Publishing Communications Ltd; Xi'an Modern Chemistry Research Institute,Xi'an 710065,China%Shanxi Jiangyang Chemical Company Limited,Taiyuan 030051,China%Central Iron & Steel Research Institute Company Limited,Beijing 100081,China%China Research and Development Academy of Machinery Equipment,Beijing 100089,China; KeAi Communications Co., Ltd
• Subjects: Alloying elements; Armored vehicles; Carbides; Carbon; Cylindrical shells; Damage power; Design; Fracture mode; Fragment mass distribution; Fragmentation; Fragments; Grain refinement; Grain size; Intergranular fracture; Manganese; Manganese steel; Mass distribution; Mechanical properties; Metallographic structure; Microcracks; Microscopy; Microstructure; Morphology; Projectile fragmentation; Projectiles; Sorbite; Steel structures; Substrates; Warheads; Weibull distribution; Projectile fragmentation; Fragment mass distribution; Metallographic structure; Damage power; Fracture mode
• ISSN: 2214-9147; 2096-3459; 2214-9147
• DOI: 10.1016/j.dt.2024.02.004

An in-depth understanding of the fracture behavior and mechanism of metallic shells under internal explosive loading can help develop material designs for warheads and regulate the quantity and mass distribution of the fragments formed. This study investigated the fragmentation performance of a new high-carbon silicon-manganese (HCSiMn) steel cylindrical shell through fragment recovery experiments. Compared with the conventional 45Cr steel shell, the number of small mass fragments produced by the HCSiMn steel shell was significantly increased with a scale parameter of 0.57 g fitted by the Weibull distribution model. The fragmentation process of the HCSiMn shell exhibited more brittle tensile fracture characteristics, with the microcrack damage zone on the outer surface being the direct cause of its high fragmentation. On the one hand, the doping of alloy elements resulted in grain refinement by forming metallographic structure of tempered sorbite, so that microscopic intergranular fracture reduces the characteristic mass of the fragments; on the other hand, the distribution of alloy carbides can exert a "pinning" effect on the substrate grains, causing more initial cracks to form and propagate along the brittle carbides, further improving the shell fragmentation. Although the killing power radius for light armored vehicles was slightly reduced by about 6%, the dense killing radius of HCSiMn steel projectile against personnel can be significantly increased by about 26% based on theoretical assessment. These results provided an experimental basis for high fragmentation warhead design, and to some extent, revealed the correlation mechanism between metallographic structure and shell fragmentation.