Chemistry of Flame Cutting - As described earlier, this cutting process is based on the ability of high purity oxygen to combine rapidly with iron heated to above 870°C. The iron gets rapidly oxidized by the oxygen to form iron oxide. The huge amount of heat liberated by the second reaction predo minates that of the first reaction, which is supplementary in most cutting operations.
The heat generated by the rapid oxidation of iron melts some of the iron adjacent to the reaction surface. This molten iron is also swept away with the iron oxide by the physical action of the oxygen jet.
The chemical requirement for the oxidation of 1 kg of iron to Fe3O4 is 0.29 m3 of oxygen.
