Effect of Texture on the Height of the Snoek Peak in Electrical Steel

Abstract

The most important factors affecting the Snoek peak height of carbon in commercial steel sheets are shortly reviewed. It is shown that the proportionality factor K_Q^*(=Q_max^-1/C_i)-for a given interstitial and a given internal damping technique-mainly is affected by the steel texture and the presence of substitutional atoms. The influence of texture and composition is illustrated for four non oriented electrical steels with Si-contents between 0 and 1.8 %. This difference in Si-content, combined with differences in C-content between the internal damping specimens, resulted in significant texture changes, providing an interesting frame not only to apply the theory on the orientation dependence of the calculated proportionality factor K_Q (developed in a previous paper), but also to discuss the effect of alloying elements on the Snoek peak height. The proportionality factors of the experimentally measured textures are calculated by making the convolution product of the orientation distribution function (ODF) of the measured texture and the distribution function of K_Q. Doing so, the effect of texture on the experimentally measured K_Q^* can be separated from the direct effect of the substitutional elements (mainly Mn, Al and Si). The latter effect is discussed in terms of the elastic strain present around substitutional atoms due to their size difference with Fe atoms.