Abstract
Effects of carbonate and fluorides in agglomerated fluxes on silicon and manganese deoxidation in submerged-arc weld metal have been examined using the bead-on-plate tests with CaO-MgO-Al2O3-SiO2 system fluxes. Slag-off rate of deoxidation products from the oxygen rich molten metal has been deter-mined using a tungsten arc in Ar atmosphere.
With the wire containing sufficient amounts of silicon, calcium carbonate in fluxes scarcely increases the oxygen content in weld metal. However, CaF2 or Na3Al6 in fluxes effectively decreases the oxygen content in weld metal. This effect of fluoride is deduced not to be derived from the evaporation of fluorine gas during welding. Ratio of oxygen content in weld metal to FeO content in slag keeps a constant value independently of the fluoride content in flux. During submerged-arc welding process deoxidation pro-duct of 50 to 100 ppm seems to be separated from molten weld pool within the solidifying. Slag-off of the deoxidation products in tungsten arc melted metal is completed within about 20 seconds.
