Abstract
Variations of the melting rates of stainless steel (308) wires with three different diameters, 0.035″, 0.045″ and 1/16″, were measured when MIG welding was carried out with them under varied conditions of gun setting (Fig. 4), i, e., when these wires had the length of their current-passing portion varied. Figures 5 and 6 give the results of measurements, which can be represented by the experimental formula S=α+βI+γIIn (dotted line of Fig. 5). Fairly good agreement was established between this formula and the theoretical one (Eq. 6) which was derived separately through analysis of these results. As in the case of the previous report on aluminium, the dripping frequency, size of drop, practical minimum current were studied by means of arc pictures, oscillograms, and observations of bead grains. The authors believe that the obtained results will be useful as reference to the welding of mild steel, the consumable electrode arc melting of other metals as well as to practical MIG welding of stainless steel.
