Abstract
Previous report has clarified that in DC-TIG arc welding of SUS 304 stainless steel the penetration ratio (penetration depth/bead width=D/W) can be improved by using flux cored stainless steel wire for CO2 gas welding.
In this report an effect of flux cored wire on penetration is further examined, and at the same time the mechanism of the penetration forming is investigated paying attention on changes of arc phenomena.
The report shows that shrinked anode is formed directly under electrode by using flux cored wire and weld with large D/W is obtained without influence of the penetration caused by quite small quantites of elements in the base metal. Meanwhile, the idea that the primary factor of the large D/ W is due to electro-magnetic convection likely generated by electric current concentrating in shrinked anode is made clear in this welding method.
For stabilized welding with large D/W penetration, a method to supply intermittently flux cored wire immediately before starting of step-movement welding is proposed.
