Investigation of the Combined Effect of Input Parameters on Liquidus Temperature and Arc Length in TIG Welding

Abstract

The liquidus temperature of a weld is that temperature at which a
metal in solid form completely turns into the liquid state. In as much
as a high liquidus temperature is desired in the welding process,
extremely high values of the liquidus temperature can lead to
spatter which will not augur well for the weld joint. Arc length is
the distance between the welding electrode tip and surface of the
weld pool. Decrease in arc length during welding, positively affects
the welder’s comfort and the weld product. The application of the
surface plot in the investigation of the combined effect of input
parameters on liquidus temperature and arc length was pursued in
this study. The central composite design matrix was used to obtain
data from sets of experiments. Mild steel coupons measuring 60mm
x 40mm x 10mm were welded with tungsten inert gas welding
process. The result of the surface plot shows that a desired value of
arc length depends on both current and voltage.