Papers by Author: Xue Liang Qiao

Abstract: Hot bands of Fe-3%Si steel containing 0.24%Cu were characterized to examine the precipitation of copper sulfides following different heat treatment schedules. It was found that copper sulfides were dominantly in a sphere shape. From 950°C to 1050°C, the precipitates were the complex of copper sulfides and aluminum nitrides. The size of the precipitates decreased and the distribution increased as the temperature increased. However, from 1050°C to 1150°C, the precipitates size increased and the distribution decreased with the rise of temperature. The precipitates were mainly complex copper-manganese sulfides. When the sample was annealed at 1050°C, air cooled to 900°C and boiling water quenched, the most fine and disperse precipitates were obtained. The average size and distribution of the precipitates was 37nm and 2.72μm-2, respectively.

Abstract: Low energy grain boundaries were considered to be important in abnormal grain growth by theoretical deduction. The disorientation angles and coincidence site lattice grain boundaries distribution of more than 20 Goss grains and their neighboring matrix grains in primary recrystallized Fe-3%Si alloy were investigated using an electron backscatter diffraction method. It was found that the frequency of low energy grain boundaries of Goss grains which are more likely to abnormally grow are higher than their neighboring matrix grains, which indicated that low energy grain boundaries play a dominant role in the abnormal grain growth of Fe-3%Si alloy. The result meets well with the abnormal grain growth theory.