炸药覆盖层厚度对爆炸焊接的影响

Effects of Covering Thickness of Explosives on Explosive Welding

为提高爆炸焊接中炸药的能量利用率以及减噪降尘,采用水状胶体对炸药的上表面进行覆盖,以SUS304不锈钢板和Q235钢板分别作为复板和基板进行了爆炸焊接实验,通过实验测量和理论计算研究了不同的覆盖层厚度对复板碰撞速度的影响,并应用爆炸焊接窗口理论和光学显微镜分析了结合界面的微观形貌。结果表明,采用水状胶体作为炸药上端覆盖层可以显著提高炸药的能量利用率,相比于裸露装药,覆盖层厚度为15、30和45mm时,复板碰撞速度分别增加了38.9%、57.5%和71.9%。实验测得的炸药爆速和碰撞点移动速度一致性良好,格尼公式所预测的碰撞速度较实验值明显偏大,而考虑加速历史所获得的碰撞速度与实验碰撞速度吻合良好;金相分析表明,在焊接窗口以内,结合界面为没有孔洞、裂缝等缺陷的波形结合,并且复板的碰撞速度越大,界面波浪幅值越大,而在靠近和高于焊接窗口上限时,界面处产生孔洞、裂缝等缺陷。

To improve the energy utilization ratio of explosive and reduce the noise and dust in explosive welding,the upper surface of explosive was covered by hydrocolloid.The explosive welding experiments were carried out by 304 stainless steel plate and Q235 steel plate as flyer plate and base plate,respectively.The effects of different covering thickness on the impact velocity of flyer plate were studied by experimental measurement and theoretical calculation,and the micro morphology of the bonding interface was analyzed through applying the window theory of explosive welding and optical microscopy.Results show that using hydrocolloid as the upper end covering can significantly improve the energy utilization ratio of explosive.Compared with bare charge,the impact velocities of flyer plate increase by 38.9%,57.5%and 71.9%respectively when the covering thickness are 15,30 and 45 mm.The detonation velocity and collision point movement velocity measured by experiment are in good agreement.The impact velocity predicted by Gurney formulas is significantly larger than the experimental value,whereas the impact velocity obtained for considering acceleration history agrees well with the experimental impact velocity.Metallographic analysis shows that within the welding window,the bonding interfaces is waveform bonding without voids,cracks and other defects and the larger the impact velocity of flyer plate is,the larger the interface wave amplitude is,whereas as closing to and higher than the upper limit of welding window,the voids,cracks and other defects will occur at the bonding interfaces.