1995 Volume 81 Issue 10 Pages 959-964
For clarifying the evaporation behavior of copper from liquid iron, the evaporation rate of copper has been studied under reduced pressures of several hundred Pa in the temperature range from 1723K to 1823K. Also, the effect of alloying element on the evaporation rate were examined.
The experimental results obtained are summarized as follows :
(1) The first order rate equation can be applied to the change of copper content in iron with time, and then the evaporation rate of copper increased with decreasing the pressure. This fact indicates that the mass transport step in the gas phase is a rate determining step under the present experimental conditions, because the mass transfer coefficient in the gas phase is inversely proportional to pressure.
(2) The apparent activation energy for removal rate of copper was calculated to be about 230 kJ/mol including the enthalpy change for the copper evaporation.
(3) The evaporation rate of copper was promoted by adding sulfur, but the additions of nickel or chromium lead to the decrease of the evaporation rate of copper.