118 



BELL SYSTEM TECHNICAL JOURNAL 



In Figs. 2, 3, and 4 are shown the magnetization curves for low, 

 medium, and high magnetizing forces for these alloys, except the 80 

 permalloy and the 1.7 V-permendur, for which the curves are sub- 

 stantially the same as for 78.5 permalloy and permendur, respectively. 

 Curves for "Armco" iron and ordinary commercial 4 per cent silicon 

 steel also are shown in these figures. All these materials were an- 

 nealed, and in the case of the 78.5 permalloy and the perminvars the 

 annealing was followed by quenching and baking, respectively. It 



6000 

 5500 

 5000 

 4500 

 [2 4000 



10 

 10 



D 



^ 3500 



Z 

 ^3000 



-S- 



O 2500 



h- 

 O 



a 2000 



z 



1500 

 1000 

 500 



0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16 0.18 0.20 0.22 0.24 0.26 0.28 

 MAGNETIZING FORCE (h) IN OERSTEDS 



Fig, 2 — Magnetization curves for several permalloys for flux densities less than 

 6,000 gausses. 



may be seen from these curves that the permalloy group reaches 

 almost saturation values long before the iron and silicon steel and the 

 other alloys have reached the lower bend in the magnetization curve. 

 With the exception of the 45-permalloy, which saturates at a fairly 

 high value, the permalloys have low saturation induction and the 

 permendur the highest. The permeability curves computed from 

 these curves are plotted in Figs. 5 and 6. In Fig. 5, curves for the 

 permalloy alloys are plotted at a smaller vertical scale than in Fig. 6 

 containing the curves for the other alloys. 



