THE EUTECTOID TKANSITION POINT OF CARBON STEELS. 



183 





Consideration of the results shown in fig. 3 makes it also reasonable to suppose 

 that the equilibrium temperature is below 730 C., the temperature at which (point P) 

 the magnetism reaches a minimum during cooling from 735 C. ; but that it is above 



660 



680 



700 720 740 



Temperature. 



760 



780 U 



800C 



723 C., the temperature at which (point Q) the magnetisation reaches a maximum 

 during subsequent re-heating. If so, we have a thermomagnetic method of deter- 

 mining the equilibrium temperature within two or three degrees as the figure shows. 

 This point is examined more closely later on. 



