Influence of grain size and strain on the barkhausen noise power of non-oriented silicon steel

Barkhausen noise powers (BNP) were measured to examine the relationship between microstructures and macroscopic properties such as Br, Hc, and μ
d
, of non-oriented silicon steels. The results show that the volume of Barkhausen jumps increases and a jump number decreases with the increase of grain size as the grain boundary works as strong obstacle to wall motions, however, the volume comes to be broken into fractions when precipitates are induced. With the increase of strain, the number of Barkhausen jumps increases and the volume decreases as the induced dislocations interfere with 180° wall motions. BNP, μ
d
and Br decrease remarkably and then gradually with the increase of strain.