Effect of the low temperature annealing on primary and secondary structures and magnetic properties of Fe-3% Si

Abstract

The processing of 3% Si steel is characterized by the use of MnS particles as a normal grain growth inhibitor. Experiments were carried out to investigate the grain growth in this material during heat treatments at low temperature. Industrial decarburized samples were annealed in the range 825-845 °C and a detailed study of grain size and texture was made by EBSD measurements. The primary grain size and texture were related to the secondary structure obtained after high temperature final annealing. The heat treatments for grain growth led to an increase in the mean grain size by 1.2 to 3 times, depending on the stability of MnS particles distribution. The increase of the primary grain size increased the core loss and decreased the magnetic induction of the fully processed material.

Second phases in steel: a review of the concept, origin, and their relevance for properties

“…This mechanism makes it possible to control the grain size of steels with relatively small volume fractions of very small particles. Typical examples for steels included in Figure 10 are AlN in austenite (commonly used in heat treatable steels) [24,66], MnS in austenite (relevant in electrical steels) [67][68][69], Nb(CN) in austenite (widely used in microalloyed HSLA steels and others) [70]. The wide range of particle-matrix combinations in Figure 10 shows how general the Zener behavior is.…”