镁/钢异种板自冲铆连接及耐腐蚀性能研究

Study on High Speed Self-Piercing Riveting Connection of Magnesium/Steel Dissimilar Plates and its Corrosion Resistance

现有的镁/钢件连接技术尚不能完全满足实际应用的技术要求,压铆、锤铆和旋转半空心铆钉自冲铆接技术(SPR)等容易使镁合金件产生开裂;电阻点焊和搅拌摩擦焊等技术连接强度太低,达不到连接强度要求;螺栓连接和拉铆必须预先打孔,存在操作和装配不方便等问题。研发了一种爆炸驱动的超高速自冲铆接用铆枪和铆接新工艺,铆钉从射钉器的射击口射出的速度大于152m/s,从而实现镁合金板与钢板的实心铆钉自冲铆接,避免镁合金板的开裂,使镁/钢牢固连接,拉剪力F_(m)≈5273.1N。采用此技术铆接的镁/钢板材试样用密封胶对铆钉及连接搭接部位缝隙进行密封后,耐腐蚀实验(GB/T6461-2002)研究表明,中性盐雾测试结果可达1500小时10级,即试样完好,无腐蚀破坏发生。

Existing technology of magnesium/steel connection cannot fully meet the technical requirements of practical applications. Press riveting,hammer riveting,and rotary semi-hollow self-piercing riveting(SPR)technology can easily crack magnesium alloy parts. Connection strengths of resistance spot welding and stirring friction welding are too low to meet the requirements.Bolt connections and riveting must be perforated in advance,which has problems such as inconvenient operation and assembly.This article reports an explosion-driven rivet gun and a new rivet technology for ultra-high-speed self-piercing riveting. The speed of rivets ejected from the firing port of the nail gun is greater than 152m/s,thereby realizing the self-punching of solid rivets of magnesium alloy plates and steel plates.This technology can avoid cracking of the magnesium alloy plate and make the magnesium/steel firmly connected. The tensile shear force F_(m)≈5273.1N. Corrosion resistance test(GB/T6461-2002)study shows that the test results of neutral salt spray can reach 1500 hours,10 Grade,that is,the sample is intact and no corrosion damage occurs.