火炮身管内膛表层温度及其梯度规律研究

火炮射击过程中高温火药燃气可使身管内膛表面材料强度降低、发生相变甚至形成熔融态，加速身管内膛表面形成烧蚀、冲刷、磨损及开裂等损伤，研究身管内膛表面温度及梯度对揭示身管损伤机理具有重要意义。以大口径155 mm火炮身管对象，建立身管热-结构耦合动力学模型，仿真研究阳线棱边倒角、表面镀铬等对身管内膛表层温度的影响规律，结合实弹射击试验后身管内膛表面热影响层检测对仿真结果进行对比。研究结果表明：身管内膛表层温度沿径向快速衰减，形成极大的温度梯度，表面温度达到1 500 ℃、190 μm处温度超过727 ℃；阳线棱边存在明显的热累积，温度比阳线表面高出300 ℃以上，阳线棱边倒角后温度约降低100 ℃；内膛镀铬后可使基体温度降低约400 ℃。

Surface Temperature and Its Gradient of Gun Barrel Bore

The high temperature combustion gas of gunpowders results in the decreased surface material strength of barrel decrease，the phase change and the melting during gun firing. This will accelerate the erosion，wear and cracking of barrel surface. Therefore，it is important to study the surface temperature and its gradientof barrel bore to explain the damage mechanism of barrel. A thermal-structure coupling dynamic model is established for 155 mm gun barrel，and the influence law of rifling edge chamfering and in-bore chromium plating on the surface temperature of barrel is simulated and analyzed. he simulated results are compared by the thickness of heat affected layer on the inner surface of barrel. The results show that the surface temperature of barrel decreases rapidly along the radial direction，forming a great temperature gradient. The temperature of the inner surface reaches 1 500 ℃，and the temperature at 190 μm exceeds 727 ℃，reaching the phase transition temperature. There is obvious heat accumulation at the edge of rifling，which makes the temperature at this point more than 300 ℃ higher than that on the surface of rifling. And the temperature at the edge of rifling decreases about 100 ℃ after chamfering. And the chrome plating in the bore can reduce the temperature of the substrate by about 400 ℃.