On the variation of saturation induction and expansion coefficients of iron with temperature

The saturation induction of iron varies temperature and shows the following characteristics. Between-200°C and 0°C the decrease in saturation induction is practically nil and this is followed by a small decrease between 0°C and 250°C. The decrease in saturation induction is again practically nil between 250°C and 400°C the decrease is at first slow followed by a rapid decrease upto the curie point. An explanation for the above variation is put forward based on the views advanced for the variation of curie temperature of Fe-Al alloys. (Mr. L.J. Balasundaram, Scientist, Physical Metallurgy Division, National Metallurgical Laboratory, Jamshedpur)