In this study, 40CrMnSiB steel cylindrical shells were tempered at 350, 500 and 600 °C to study the effect of tempering temperature on the dynamic process of expansion and fracture of the metal shell. A mid-explosion recovery experiment for the metal cylinder under internal explosive loading was designed, and the wreckage of the casings at the intermediate phase was obtained. The effects of different tempering temperatures on the macroscopic and microscopic fracture characteristics of 40CrMnSiB steel were studied. The influence of tempering temperatures on the fracture characteristic parameters of the recovered wreckage were measured and analyzed, including the circumferential divide size, the thickness and the number of the circumferential divisions. The results show that as the tempering temperature was increased from 350 to 600 °C, at first, the degree of fragmentation and the fracture characteristic parameters of the recovered wreckage changed significantly and then became essentially consistent. Scanning electron microscopy analysis revealed flow-like structure characteristics caused by adiabatic shear on different fracture surfaces. At the detonation initiation end of the casing, fracturing was formed by tearing along the crack, which existed a distance from the initiation end and propagated along the axis direction. In contrast, the fracturing near the middle position consists of a plurality of radial shear fracture units. The amount of alloy carbide that was precipitated during the tempering process increased continuously with tempering temperature, leading to an increasing number of spherical carbide particles scattered around the fracture surface.

在这项研究中，对40CrMnSiB钢制圆柱壳在350、500和600°C进行回火，以研究回火温度对金属壳膨胀和断裂动态过程的影响。设计了金属炸药在内部爆炸载荷下的中爆炸恢复实验，获得了中间阶段壳体的残骸。研究了不同回火温度对40CrMnSiB钢的宏观和微观断裂特性的影响。测量并分析了回火温度对回收残骸断裂特性参数的影响，包括周向分隔尺寸，厚度和周向分隔数量。结果表明，随着回火温度从350升高到600°C，残骸的破碎程度和断裂特征参数发生了显着变化，然后基本保持一致。扫描电子显微镜分析揭示了由绝热剪切作用在不同断裂表面上引起的类似流动的结构特征。在套管的起爆起始端，沿着裂缝的破裂形成裂缝，该裂缝与起始端相距一段距离，并沿轴向传播。相反，在中间位置附近的压裂由多个径向剪切压裂单元组成。在回火过程中析出的合金碳化物的量随回火温度而连续增加，导致散布在断裂表面周围的球形碳化物颗粒数量增加。