FACTORS AFFECTING MAGNETIC QUALITY 



277 



the curve giving the mean values of many determinations. The hysteresis 

 decreases rapidly at small carbon contents, when these are of the order of 

 magnitude of the solid solubility at room temperature. 



^ 600 



D 300 



0.01 0.02 0.03 



SOLUBILITY IN PER CENT BY WEIGHT 



Fig. 26 — Approximate solubility curves of carbon, oxygen and nitrogen in iron. 



% 2400 



ui 2000 

 o 



-C— - 



> o 



0.04 0.08 0.12 



PER CENT CARBON IN IRON 



Fig. 27 — Effect of carbon content on hysteresis in iron. Yensen and Zieglcr. 



Cioffi'- has purified iron from carbon, oxygen, nitrogen and sulfur by 

 heating in pure hydrogen at 1475°C, and has measured the permeabiUty 



12 p. p. Cioffi, Phys. Rev. 39, 363-7 (1932). 



