To improve welding quality, a method of proportional-integral-differential （PlD） parameters tuning based on pulsed gas metal arc welding （P-GMAW） control was put forward. Aiming at the request of dynamic responsiv...To improve welding quality, a method of proportional-integral-differential （PlD） parameters tuning based on pulsed gas metal arc welding （P-GMAW） control was put forward. Aiming at the request of dynamic responsiveness of PGMA W constant current control, a self-developed welding waveform wavelet analyzer was employed. By tuning the proportional parameter, integration time and differential time in sequence, the optimal PID parameters could be achieved. The results showed that, due to the PID parameters tuned by this method, the welding process was stable and the weld bead appearance was nice. The requirement of dynamic responsiveness of P-GMAW constant current control was fully met.展开更多
在焊接热输入相同的条件下对比研究了直流反接的熔化极惰性气体保护焊(Gas metal arc welding,GMAW)中直流脉冲模式(Pulsed gas metal arc welding,P-GMAW)和恒流模式(Constant current gas metal arc welding,CC-GMAW)对5083-H111铝合...在焊接热输入相同的条件下对比研究了直流反接的熔化极惰性气体保护焊(Gas metal arc welding,GMAW)中直流脉冲模式(Pulsed gas metal arc welding,P-GMAW)和恒流模式(Constant current gas metal arc welding,CC-GMAW)对5083-H111铝合金薄板焊接接头的成形、微观组织和力学性能等的影响。结果表明:5083铝合金P-GMAW焊接接头成型平整美观,脉冲在一定程度上抑制了焊缝气孔的生成。热输入相同时P-GMAW焊缝内生成的柱状晶面积占比更大,表明P-GMAW热源焊接的熔池温度梯度更大。两种模式焊缝的力学性能相近,接头强度约为288~303 MPa,达到了母材抗拉强度的90%。接头的断裂位置均在焊缝区,断口呈韧性断裂的韧窝形貌,焊缝强度的降低与其粗大的晶粒和气孔缺陷有关。展开更多
Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding wire.Suppression of short-circuit current was used to reduce spatter.Ar...Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding wire.Suppression of short-circuit current was used to reduce spatter.Arc length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to occur.Short-arc P-GMAW with or without arc length stabilizer was compared.The droplet transfer,arc behaviors and weld bead profiles were investigated and compared based on the high-speed photography and observation of weld cross-section.When the arc length stabilizer was deactivated,the arc length was unstable and too short.The droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit current.There was also a small proportion of short circuit complete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit current.With arc length stabilizer,droplet transfer modes were short circuit complete transfer and spray transfer.The spray transfer had the largest droplet impact,no short circuit and no spatter.With the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were acquired.This provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the incomplete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.展开更多
文摘To improve welding quality, a method of proportional-integral-differential （PlD） parameters tuning based on pulsed gas metal arc welding （P-GMAW） control was put forward. Aiming at the request of dynamic responsiveness of PGMA W constant current control, a self-developed welding waveform wavelet analyzer was employed. By tuning the proportional parameter, integration time and differential time in sequence, the optimal PID parameters could be achieved. The results showed that, due to the PID parameters tuned by this method, the welding process was stable and the weld bead appearance was nice. The requirement of dynamic responsiveness of P-GMAW constant current control was fully met.
文摘在焊接热输入相同的条件下对比研究了直流反接的熔化极惰性气体保护焊(Gas metal arc welding,GMAW)中直流脉冲模式(Pulsed gas metal arc welding,P-GMAW)和恒流模式(Constant current gas metal arc welding,CC-GMAW)对5083-H111铝合金薄板焊接接头的成形、微观组织和力学性能等的影响。结果表明:5083铝合金P-GMAW焊接接头成型平整美观,脉冲在一定程度上抑制了焊缝气孔的生成。热输入相同时P-GMAW焊缝内生成的柱状晶面积占比更大,表明P-GMAW热源焊接的熔池温度梯度更大。两种模式焊缝的力学性能相近,接头强度约为288~303 MPa,达到了母材抗拉强度的90%。接头的断裂位置均在焊缝区,断口呈韧性断裂的韧窝形貌,焊缝强度的降低与其粗大的晶粒和气孔缺陷有关。
基金the MARK III Materials Research Project of Ministry of Industry and Information Technology of China。
文摘Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding wire.Suppression of short-circuit current was used to reduce spatter.Arc length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to occur.Short-arc P-GMAW with or without arc length stabilizer was compared.The droplet transfer,arc behaviors and weld bead profiles were investigated and compared based on the high-speed photography and observation of weld cross-section.When the arc length stabilizer was deactivated,the arc length was unstable and too short.The droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit current.There was also a small proportion of short circuit complete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit current.With arc length stabilizer,droplet transfer modes were short circuit complete transfer and spray transfer.The spray transfer had the largest droplet impact,no short circuit and no spatter.With the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were acquired.This provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the incomplete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.
