  The effects of oxygen flow speed and pressure on the iron and mild steel
combustion are investigated experimentally and theoretically. The studied
specimens are vertical cylindrical rods subjected to an axial oxygen flow and
ignited at the upper end by laser irradiation. Three main stages of the
combustion process have been identified experimentally: (1) Induction period,
during which the rod is heated until an intensive metal oxidation begins at its
upper end; (2) Static combustion, during which a laminar liquid "cap" slowly
grows on the upper rod end; and, after the liquid cap detachment from the
sample, (3) Dynamic combustion, which is characterized by a rapid metal
consumption and turbulent liquid motions. An analytical description of these
stages is given. In particular, a model of the dynamic combustion is
constructed based on the turbulent oxygen transport through the liquid
metal-oxide flow. This model yields a simple expression for the fraction of
metal burned in the process, and allows one to calculate the normal propagation
speed of the solid metal--liquid interface as a function of the oxygen flow
speed and pressure. A comparison of the theory with the experimental results is
made.
