| Drag lines are line markings that
show on the surface of the cut. Good drag lines are almost straight up and down, as shown
in figure 4-31, view A. Poor drag lines, as shown in figure 4-31, view B, are long and
irregular or curved excessively. Drag lines of this type indicate a poor cutting procedure
that could result in the loss of the cut (figure 4-31, views B and C). Draglines are the
best single indication of the quality of the cut made with an oxygas torch. When the
draglines are short and almost vertical, the sides smooth, and the top edges sharp, you
can be assured that the slag conditions are satisfactory.
SIDE SMOOTHNESS
A satisfactory oxygas cut shows smooth sides. A grooved,
fluted, or ragged cut surface is a sign of poor quaility.
TOP EDGE SHARPNESS The top edges resulting from an
oxygas cut should be sharp and square (figure 4-31, view D). Rounded top edges, such as
those shown in view E of figure 4-31, are not satisfactory. The melting of the top edges
may result from incorrect preheating procedures or from moving the torch too slowly. |
|
