大口径机枪枪管失效规律研究

为了研究大口径枪管在寿命过程中的变化规律，寻找失效原因，对两根不同材料枪管进行了综合寿命试验。分析了内膛阳线直径变化、内膛表面形貌变化、密集度、初速下降率及椭圆弹孔率与枪管寿命之间的关系，得到了某机枪两种寿命相差3 000发的寿终枪管的共同规律为：枪管寿终均表现为椭圆弹孔率超过本组射弹量的50%，内膛四锥、五锥的损伤是造成枪管产生椭圆弹孔的根本原因；在射弹量为1 200发时，枪管内膛五锥处的铬层已经严重成片脱落；由于枪管内膛尾部出现了鼓形，用量规测量得到的枪管内膛直径大小并不能反应枪管性能，但尾部阳线直径变化越快，枪管寿命越短。

Research on the Performance Decay Rule of Large Caliber Machinegun Barrel

In order to study the erosion rule of large caliber machinegun barrel in lifetime and find out the determinants of barrel life, the life test was done on two barrels made of different materials. The fundamental cause of the ellipse shot holes due to the erosion of the forth and fifth tapers are found out by analyzing the relations among the barrel life and the changes of bore land diameter and bore surface topography, accuracy and dispersion, decreased rate of muzzle velocity and number of ellipse shot holes, which results in the different life of two barrels; when firing 1 200 shots, the chrome layer in the fifth taper of bore fell off, the bore diameter measured by gauge can’t reflect barrel performance, but the barrel life is determinated by the changing of land diameter in the rear of barrel.