溶融銅への固体鉄の溶解速度

抄録

The solution rate of solid iron in liquid copper was studied under dynamic conditions. A cylindrical iron was rotated in liquid copper or liquid Cu-Fe alloys for 40 to 240 sec at about 240, 560 and 820 revolutions per minute at about 1220°, 1300° and 1380°C. The dependence of the solution rate on the iron concentration in liquid copper was investigated. Its dependence at the highest temperature can be explained neither by the Berthoud equation nor by Lommel and Chalmers’ equation, but approximately by an equation in which the driving force is expressed by the difference in the activity of solute between saturation and bulk liquid. A theoretical derivation of the new equation was tried and a consideration was made from the standpoint of thermodynamics of irreversible processes. The solution rate constant defined by the equation increases with increasing temperature and rotational speed. The dependence of the logarithm of the solution rate constant on the reciprocal of absolute temperature gives the activation energy ranging from 40 to 47 kcal/mol. The exponent of Reynolds numbers determined from the dependence of the solution rate constant on the peripheral velocity of rotating cylinder ranges from 0.5 to 0.7.