Effect of stress on the law of approach to saturation magnetization in carbon steels

In high fields where the magnetization is approaching saturation, the resolved magnetic polarization I can be expressed by a power series of the inverse of external field H as: I=I/sub s/-b/H/sup 2/-c/H/sup 3/ . . ., or alternatively in terms of the reversible permeability mu /sub rev/=1+(2b/H/sup 3/+3c/H/sup 4/+ . . .)/ mu /sub 0/ where I/sub s/ is the spontaneous magnetic polarization and b, c, are constants. These equations express the law of approach to saturation magnetization. The coefficient b for a cubic crystal has been deduced as b=0.0762/I/sub s/(K+1.5( lambda /sub 100/- lambda /sub 111/) sigma )/sup 2/, where sigma is the applied stress and others are magnetic constants. The values of reversible permeability mu /sub rev/ under biasing field H were measured for carbon steels with applied stresses. The results showed that the square root of 2b changed linearly with the applied stress, The values of magnetic constant K and lambda /sub 100/ - lambda /sub 111/ were calculated, They agreed with the standard values, but were affected by chemical composition and heat treatment of materials, especially in lambda /sub 100/- lambda /sub 111/.< >