Abstract
Solubilities of nitrogen in the liquid iron-nickel and iron-cobalt alloys at 1 600° were measured by means of two methods: in a Mo-resistance furnace and in a mercury-gap high frequency induction furnace. The results obtained by the two methods were well agreed each other within the accuracy of 3ppm.
The solubility curve of iron-cobalt showed a good agreement with the data found in the literatures previous workers within the accuracy of experimental' errors. However, the solubility of the nitrogen in the nickel alloys showed a higher value at the nickel rich corner.
The diffusion coefficients of nitrogen in those alloys were determined by the capillary reservoir method at 1600°C. With increasing the nickel and cobalt concentrations, the diffusion coefficients were slightly increased in comparison with that in the pure iron.
Based on the pertiment various theories, the diffusion coefficients of some elements in the iron-based alloys were discussed. The diffusion coefficient was well described by a Stokes-Einstein-type equation as follows:
D=a′·1/η·1/γ2·5
where a′ is a constant, η the viscosity of iron-alloys and γ the covalent radius of a diffusing element.
