MetFab - Air Products Welder's Handbook - Flipbook - Page 46
Oxy-fuel gas cutting
Oxygen, used with a fuel gas such as
acetylene or propane can be used for many
processes including cutting, brazing and
heating. Only acetylene fuel gas is suitable
for welding. Oxy-fuel is a portable, lowcost, versatile, safe and easy to use process
but must only be used only by trained
personnel.
When cutting, any fuel gas can be used
with oxygen to cut ferrous metals. The
process can easily be automated to enhance
productivity and cut accuracy. Acetylene
is the only commonly used fuel gas
that can produce a variety of bevel edge
preparations on plate, pipe and tube. All
edge preparations require grinding of the
cut surface prior to welding to remove the
oxide layer.
Nozzle
Cutting oxygen jet
Cut face
42
Molten slag and
metal ejected from cut
The cutting action depends on a chemical
reaction between oxygen and the iron (Fe)
in the steel. A preheat flame is used to raise
the surface of the metal to the ignition
temperature at which the reaction takes
place. The heat from the reaction melts the
metal which is blown from the cut by the
oxygen jet.
