Equilibrium Solutions of Nitrogen in Columbium-Base Alloys
Technical documentary rept. 15 Mar 1963-15 Mar 1964
ILLINOIS UNIV AT URBANA DEPT OF MINING METALLURGY AND PETROLEUM ENGINEERING
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Thermodynamic and mechanical properties of columbium-nitrogen and columbium-zirconium-nitrogen alloys were determined. The partial pressure of nitrogen in equilibrium with single-phase and two-phase alloys of various binary and ternary compositions was determined as a function of temperature for temperatures between 1500 deg C and 2100 deg C. Heat of solution of nitrogen, heat of formation of Cb2N, and heat of solution of Cb2N values were determined for pure columbium and columbium with 0.86 wt Zr. Internal friction and hardness were measured for several alloys which had been quenched from above 1500 deg C. For the radiation quench used, solid solutions with 0.075 wt nitrogen and over could not be retained without precipitation. For the coarse-grained specimens hardness increased from 107 KHN for the pure columbium to 178 KHN for a two-phase alloy containing 0.68 wt nitrogen.
- Inorganic Chemistry