
420 Fundamentals of Machining Processes
220 kW the machining speed is 2500 mm/min, which is 5 times greater than
that for oxygas cutting (Figure 12.37). As the power is increased, the efcient
removal of melted metal is found to need a corresponding rise in the gas ow
rate (Figure 12.38). Figure 12.39 shows the relationship between the material
removal rate and the machining speed. Accordingly, an optimum machining
speed should be selected for achieving the maximum removal rate.
Plasma cutting
Flame cutting
Machining speed
Plate thickness
FIGURE 12.37
Effect of plate thickness on machining speed for ame cutting and plasma machining.