... welding,less investment and savings wire,a particular low price,the advantages of simple operation 1.MZ-type semi-automatic submerged arc welding production line ... widely used on all kinds of steel pipe,round-and cone,polgon-highpoles such as the welding ... luminous,open-length welding,weldingspeed 2-3m/min.With high speed welding,less investment and savings wire,a particularly ...