Abstract
The effect of torch hardware, operating parameters, and powder type on substrate surface heat flux was quantitatively investigated using calorimeters. The Sulzer-Metco 6P oxyacetylene torch with two nozzles and two air caps and the Alamo PG-550 torch were studied using designed experiments to show the effects of total combustible gas flow, oxy-fuel ratio, air flow, and standoff distance on surface heat flux. Air caps which directed cooling air toward the flame produced lower heat flux than air caps providing gun cooling. For the 6P torch, nozzle geometry did not have a significant effect on heat flux. With low air flow rates, both torches exhibited similar heat fluxes. At high air flows, the surface heat flux of the PG-550 was larger than that of the 6P.
