A new complex arc welding process is proposed. The aim is to achieve higher production efficiency and higher welding quality required in a small batch production. The process combines some element welding to obtain optimum multi-layer weld. The element weldings are conventional TIG, MIG (MAG), and their add-on function versions using filler wire(s) and magnetic control together. The process selects appropriate element welding for each individual pass considering the characteristics of bead formation.
The application of the element weldings to the stainless clad steel has been investigated to obtain the fundamental data, such as the bead formation, weld metal, pass numbers and mechanical properties. Experiments showed the following results. Some combination of two element weldings reduce the penetration compared with conventional TIG or MIG welding, resulting in decreased dilution of elements in stainless steel. The deposition rate rises without spoiling welding speed and operability. The Ni and Cr contents in the weled metal of the TIG added with a filler wire and magnetic control is higher than that of TIG welding.
The tensile fracture of welds in the complex process occurred in the portion from the base metal to HAZ, and that in the single process occurred in the base metal. The tensile strength of welds in the complex process is equal of in the single process, and its value is equal or larger than the stainless clad steel base metal. The peak of the hardness in the weld metal is lower and narrower.