464 



TABLE 490.— MAGNETIC PROPERTIES OF IRON AND STEEL 



Electrical sheets 



Chemical composi- 

 tion in percent 



C 



Si 



Mn 



P 



IS 



Coercive force -J 



Residual B 



Maximum permeability < 



B for H = 150. 



47rl for saturation. 



Electro- 

 lytic 

 iron 



.024 

 .004 

 .008 

 .008 

 .001 



2.83 

 [.36] 



11400 

 [ 10800] 



1850 

 [14400] 



19200 

 [ 18900] 



21620 

 [21630] 



Good 

 cast 

 steel 



.044 



.004 



.40 



.044 



.027 



1.51 

 [.37] 



10600 

 [11000] 



3550 

 [14800] 



18800 

 [19100] 



21420 

 [21420] 



Poor 

 cast 

 steel 



.56 



.18 



.29 



.076 



.035 



7.1 

 (44.3) 



10500 

 (10500) 



700 

 (170) 



17400 

 (15400) 



20600 

 (20200) 



Steel 



.99 

 .10 

 .40 

 .04 

 .07 



16.7 

 (52.4) 



13000 

 (7500) 



375 

 (110) 



16700 

 (11700) 



19800 

 (18000) 



Cast 

 iron 



3.11 

 3.27 



.56 

 1.05 



.06 



11.4 

 [4.6] 



5100 

 [5350] 



240 

 [600] 



10400 

 [11000] 



16400 

 [16800] 



Ordinary 



.036 

 .330 

 .260 

 .040 

 .068 



Silicon 

 steel 



.036 

 3.90 

 .090 

 .009 

 .006 



[1.30] 1771 



[9400] [9850] 



[3270] [6130] 



[18200] [17550] 



[20500] [19260] 



Brackets indicate annealing at 800°C in vacuum. 

 Parentheses indicate hardening by quenching from cherry-red. 



CAST IRON IN INTENSE FIELDS 



TABLE 492.— CORRECTIONS FOR RING SPECIMENS 



In the case of ring specimens, the average magnetizing force is not the value at the mean 

 radius, the ratio of the two being given in the table. The flux density consequently is not 

 uniform, and the measured hysteresis is less than it would be for a uniform distribution. 

 This ratio is also given for the case of constant permeability, the values being applicable for 

 magnetizations in the neighborhood of the maximum permeability. For higher magnetiza- 

 tions the flux density is more uniform, for lower it is less, and the correction greater. 



SMITHSONIAN PHYSICAL TABLES 



