Simple equations for the magnetization and reluctivity curves of steel

The normal
B-H
curves of several types of steel are shown to be approximated by the equation
H= (k_{1} e^{k_{2}B^{2}} + k_{3}) B
. The reluctivity (
H/B
) and its derivative with respect to
B
are given by simple equations that are especially useful in the finite element method of analyzing steel magnetic circuits.