THE EUTECTOID TRANSITION POINT OF CARBON STEELS. 



189 





made upon the 0'36 and 0'60 per cent, steels. The thicker-lined curves were 

 obtained during uninterrupted heating and cooling as in fig. 5. The letters P. Q, M 

 and the lines A and B have the same significance as before. 



It will be seen at once that the point Q no longer occupies the position calculated 

 for it on the assumption that MQ should represent the contribution of the excess iron, 





650' 



800 C 



and QP that of the eutectoid iron to the total magnetisation MP. In each case the 

 eutectoid iron appears to contribute more than its calculated share to the total 

 magnetisation. The apparent excess is very marked in the 0'60 per cent, steel. 



The error due to the shortness of the specimen, already mentioned, would increase 

 with the percentage of carbon, and would be much more important in the 0'60 



