270 



BELL SYSTEM TECHNICAL JOURNAL 



10^X10 

 o 



£2 50 



2 



D 100 



X 



< 



2 c« 



40 50 60 



PER CENT NICKEL 



Fig. 20 — Dependence of the initial and maximum permealiilities (yuo, Mm) of iron-nickel 

 alloys on the heat treatment. 



oz 



«i o 



20 40 60 80 100 



PER CENT COBALT IN IRON 



Fig. 21 — Variation of B, and Q of iron-cobalt alloys with composition. 



