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BELL SYSTEM TECHNICAL JOURNAL 



value for Bs since for values of II approaching infinity, the equation 

 yields the result that y = BJBr ^ A = ^J2 whence Bs = V2 Br, while 

 values of B in excess of V2 Br are commonly encountered at ordinary 

 values of //. 



Characteristic Curves for Magnet Steel 

 In Fig. 14 are shown demagnetization curves and (BII) curves for 

 the various types of magnet steel with which the writer has had ex- 

 perience. It should be remembered that while these curves are more 



11,000 



280 240 200 160 120 80 



H IN OERSTEDS 



Fig. 14 — Typical demagnetization curves and curves of BH vs. B for various kinds of 



magnet steel. 



or less typical of the steels in question, there is no one curve which 

 can be given as the curve for the material. There will be as many 

 curves as there are samples tested, because magnetic characteristics 

 of a piece of magnet steel, or any other magnetic material depend upon 

 the whole previous thermal history of the sample from the time of 

 melting to the time of testing, the amount of hot and cold working 

 the sample has received, and the conditions of stress in the material 



