提高电弧穿透能力是等离子弧焊接领域的重要课题.自主设计并搭建了金属粉末再压缩等离子弧焊接新工艺试验平台，采集焊接过程电信号、视觉信号、弧光光谱信号等，并从焊缝成形、电弧电压、熔融金属过渡、弧光光谱等方面对金属粉末再压缩等离子弧焊接过程进行了初步的研究.在相同焊接电流195 A条件下，与常规等离子弧焊接工艺相比，金属粉末再压缩等离子弧焊接焊缝熔深增加1.29 mm、熔宽减少1.65 mm、电弧电压升高0.63 V.在波长为230 ~ 270 nm范围内，与常规等离子弧焊接相比，金属粉末再压缩等离子弧焊接中Fe和Cr元素的特征谱线明显增多. 结果表明，在相同电流条件下，与常规等离子弧焊接相比，金属粉末再压缩等离子弧焊接电弧穿透能力增强.
Improving arc penetrability is of great importance in plasma arc welding. The experiment system of the new welding process, named plasma arc welding with additional focusing by metal powder, is designed and developed in this study, and the welding test is conducted. The data acquisition of electric signal, visible signal, and spectral signal is done during welding process. The weld formation, arc voltage, molten metal transfer, and arc spectrum are analyzed. Under the same welding current 195 A, comparing plasma arc welding with additional focusing by metal powder with traditional plasma arc welding, weld penetration increases 1.29 mm in value, and weld width decreases 1.65 mm in value, and arc voltage increases 0.63 V in value. Within the scope of 230 ~ 270 nm in wave length, characteristic spectral lines of element Fe and Cr during plasma arc welding with additional focusing by metal powder increase in quantity, compared with characteristic spectral lines during traditional plasma arc welding. It is found that, under the same welding current, arc penetrability in plasma arc welding with additional focusing by metal powder is bigger than that in traditional plasma arc welding.
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