CMT能量输入特点与熔滴过渡行为

为分析CMT焊接方法的工艺特点,采用高速CCD摄像机建立了电弧形态和熔滴过渡视觉传感系统并且通过电流、电压传感器建立了波形采集系统,以此分析其能量输入特点和熔滴过渡行为.结果显示,CMT焊接波形控制呈现典型的直流脉冲特征,焊接时热输入较低;在CMT短路过渡过程中,熔滴尺寸随焊接电流的增加幅度不大,将熔滴尺寸控制在一定范围内可实现稳定的短路过渡.CMT短路过渡通过焊丝回抽,避免了大的电磁力,有效地消除了飞溅.当电流增大到一定值时,其过渡形式将转变为射滴过渡和短路过渡的混合过渡.

Energy input and metal transfer behavior of CMT welding process

To analyze process characteristic of CMT welding method,experimental systems to photograph arc shape and molten droplet images by using high-speed charge coupled device camera and to record welding cur- rent and arc voltage in synchronism were established. The energy input characteristic and metal transfer behav- ior were analyzed by above-mentioned experimental systems. The results show that CMT welding process is typ- ical direct current impulse process and has lower heat input during welding. The droplet size does not increase obviously with raising welding current. The stable droplet size is beneficial for short circuiting transfer. The spatter can be eliminated with the aid of adscititious force. A hybrid metal transfer made up of projected trans- fer and short circuiting transfer also can be found when welding current reaching a rather large value.