Влияние дисперсности порошков железа на закономерности их окисления при нагревании в воздухе

The laws of oxidation process of industrial micron powder and electro blasting iron nanopowder at heating in the air under conditions of linearly increasing temperature and isothermal mode have been studied. Oxidation process staging in conditions of linear heating conditioned by total influence of powder fractional composition and phase composition and structure of the oxide layer formed on particle surface was shown. It was shown that nanopowder oxidation process in comparison with micron powder in isothermal conditions (250…600 °С) was described by linear law and occurred in kinetic mode (Еа=100±7 kJ/mole). The conditions of thermogravimetry at which nanopowder thermal self-ignition occurs were determined; the experimentally fixed value of critical temperature was substantiated on the basis of numerical estimation of sample surface heating parameter.