Aiming at the ultra-high dynamic characteristics and precise control requirements of welding power supply in the extremely complex underwater environment,the main cir-cuit of fast-frequency pulsed welding power supply based on SiC module is designed,an all-digital control system is de-veloped,and the local dry underwater fast-frequency pulsed MIG(LDU-FFPMIG)welding power supply is exploited.The welding power supply has a rated output current of 400 A,which can accurately output fast-frequency pulsed current waveforms with the fast-frequency frequency of 0～30 kHz and the fast-frequency current amplitude of 200 A.A new LDU-FFPMIG process is proposed,and the fast-frequency pulsed is applied to perform 304 stainless steel local dry underwater MIG welding,the influence of fast-frequency pulsed on local dry underwater pulsed MIG welding is revealed.The results show that the self-developed LDU-FFPMIG welding power supply achieves stable local dry underwater MIG welding and good weld formation.The introduction of fast-frequency pulsed current significantly improves arc energy density and arc stability,reduces the melting width(B),increases the penet-ration depth(H),reduces the weld forming coefficient(B/H)by about 30%,and refines the grain.
关键词
焊接电源/SiC模块/全数字化快频脉冲波形/局部干法水下MIG焊
Key words
welding power supply/SiC module/all-digital control fast-frequency pulsed waveform/local dry underwater MIG welding
维普
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