Sn segregation and its influence on electrical steel texture development

During the recrystallization microalloyed Sn in non-oriented electrical ste el segregates to the surface and on grain boundary and affects the texture development. In spite of the fact that the grain boundary segregation is mu ch smaller compared to surface segregation, both have an influence on recry stallization and on texture development in electrical steel. Auger electron spectroscopy (AES) was used to measure the grain boundary and surface segr egation of Sn in non-oriented electrical steels alloyed with different Sn w eight contents (0.025, 0.05 and 0.1%). The grain boundary segregation of th e specimens, which were previously aged at 530 degrees C for various times and were fractured under UHV conditions, was measured. The surface segregat ion temperature dependence and its kinetics were followed in polycrystallin e specimens in the temperature range from 400 to 900 degrees C on the grain s of known crystallographic orientations: (100), (111) and (110). The textu res were measured by X-ray texture goniometer and the results were presente d as orientation distribution functions (ODF). By controlled surface and gr ain boundary segregation it is possible to achieve the selective grain grow th which improves the electrical properties of non-oriented electrical stee l. The best results were obtained by alloying it with 0.05 wt% Sn.