等离子弧焊是在钨极氩弧焊基础上发展起来的一种高能密度热源的先进熔焊方法。它依靠机械、热和电磁收缩效应使等离子弧的能量密度提高到10~5～1O~6W/cm~2,温度提高到25000°K以上,因而可以较高速度焊接许多可焊性差的金属材料,特别是可利用熔孔效应实现不加衬垫的单面自动焊,即一次焊透的对接自动焊。近十多年来,各工业发达国家都十分重视这种焊接方法的研究发展工作。国内也有不少工厂已在生产中应用。但是这种焊接方法要求控制的参数很多,对每一个参数及其相互配合的控制要求较高,许多应用 Plasma arc welding is an advanced fusion welding method developed on the basis of TIG welding. It relies on mechanical, thermal and electromagnetic shrinkage effects to increase the plasma arc energy density to 10 ~ 5 ~ 10 ~ 6W / cm ~ 2 and raise the temperature to more than 25000 ° K, so that many solderable metallic materials can be welded at a higher speed , In particular, can use the melt hole effect unpadded single-sided automatic welding, that is, a penetration welding butt welding. In the past decade or so, all industrialized countries have attached great importance to the research and development of such welding methods. There are many domestic factories have been applied in production. However, this welding method requires a lot of parameters to be controlled, and requires high control of each parameter and its cooperation. Many applications