THE EUTECTOID TRANSITION POINT OF CAEBON STEELS. 



199 



more gradually, than during continuous heating from the atmospheric temperature. 

 The same effect is shown more strikingly in figs. 12 and 13 below. 



It will be noticed that, according to the views already outlined, rapid solution 

 should not be possible until the temperature of the specimen has risen sufficiently 

 far above the eutectoid point to make the differences between the equilibrium 

 concentrations at the boundary films considerable. 



680 



700 



720 



B 



Fig. 2. 



740 



Fig. 11. 



700 



720 



760 



7 BOG 



740 







760 



Fig. 11, together with figs. 12 and 13, shows that what happens is in agreement 

 with this deduction. 



The fact that during heating from the air temperature the solution proceeds 

 rapidly immediately after it begins is additional evidence of the existence of the lag 

 already considered in 3. 



18. Application to the Case of Interrupted Solution of the Eutectoid. 

 Fig. 2 (see this page) serves to show the behaviour of the material after interrupted 

 heating. To interpret the results we have to consider what will happen when the 



78CTc 



