SURFACE AND BULK PROPERTIES OF Fe-C MELT UPON INTERACTION WITH THE AlO-BASED REFRACTORY CERAMICS

Using the method of sessile drop, the interaction of rail steel with the AlO-based refractory ceramics has been studied depending on the holding temperature and time and also on the gas-phase composition. It is shown that wetting angles were changed substantially (from about 145° to 125–130°) only upon isothermal holding at low temperatures. The effect of the roughness of ceramic substrate on a change in the wetting angle is studied. It is stated that its lower values took place on ceramics with the smaller roughness. The surface tension and density of rail steel are studied. An essential difference in the surface tensions upon heating and cooling was shown. It is found that, unlike pure iron, the inversion of the temperature coefficient ∂σ/∂Τ was observed for the rail steel. The adhesion work was calculated. It was shown its sharp increase for the initial 30 minutes of experiment (up to 600 mN/m) and, then, a gradual growth (to about 700 mN/m) independently of regimes of heating and cooling.