STUDY ON THE EXPANSION AND FRACTURE OF A CYLINDRICAL 50SiMnVB STEEL SHELL UNDER DIFFERENT TEMPERING TEMPERATURES

摘要

To study the effects of different tempering temperatures on theexpansion and fracturing of a warhead and the subsequent formation offragments, this paper has selected 50SiMnVB steel which was temperedseparately at 450°C and 650°C as the objects for study.Images of the expansion and fracture processes of the cylindrical shellwere captured by using high speed photographic technology. In addition,this paper used the AUTODYN-3D finite element software to numericallysimulate the expansion and fracture processes of 50SiMnVB steel. Theformation of fragments was studied through the use of ScanningElectronic Microscopy and Metallographic Analysis.It was found that, with the increasing of the tempering temperature, thestructure, composition and shape of 50SiMnVB steel’s microstructurechanged constantly. Observations made include; an increase in strengthand toughness together with an increase in plastic deformation and afurther change in fracture mode from tensile-shear factor to that of shearfactor. With the increasing of the tempering temperature, the time neededfor fracture generation and detonation product leakage on the outersurface of the 50SiMnVB shell was delayed under detonation loading.The expansion distance of the 50SiMnVB shell under the temperingtemperature, 650°C is increased by 23.95% when compared with theother test cylinder under the tempering temperature of 450°C , and theexpansion velocity is increased by 11.0%.