Study On The Nitrogen Solubility In Sm-Fe Alloy

Nitrogen atom form a gap depth nitrogen samarium alloy, not only can improve samarium alloy magnetic properties, and mechanical properties of samarium write ferroalloys, Curie temperature, corrosion resistance, etc. have been greatly improved.However, there is a total of nitriding samarium iron main methods of solid state nitriding,nitriding efficiency is low, nitriding is poor, is not conducive to industrial production.Therefore, the group proposed the high-pressure liquid nitriding, materialized nitrogen quenching method for producing Sm-Fe-N permanent magnet, the process of nitrogen solubility in the liquid alloy of samarium is the key issue. This paper studies on the thermodynamic problem of nitrogen dissolved in samarium iron alloy under high pressure conditions the bottom blowing.Samarium iron thermodynamic phase diagram analysis, rapid quenching process,samarium alloy structure will remain empty portion of the liquid, and controlling the cooling rate and other conditions will inhibit the precipitation of α-Fe. Samarium alloy by nitrogen thermodynamic theory shows that changing the pressure, temperature,alloying elements will affect the solubility of nitrogen gap in samarium iron alloy. In this study, high temperature and pressure autoclave, using a high pressure nitrogen bottom blowing by way of single factor experiment design, main pressure factors on nitrogen solubility problems in samarium iron alloy.The results show that: in the pressure range 0.5MPa ~ 1.0MPa nitrogen, samarium alloys with increasing nitrogen content increased pressure; and through analysis showed that nitrogen diffusion in samarium iron alloy in nitrogen dissolved in the process of limiting factor. High pressure nitriding bottom blowing ways to increase the rate of dissolution of nitrogen; samarium alloy oxygen, carbon and other impurities have great influence on the solubility of nitrogen in samarium Ferroalloy.