Abstract: Effect of annealing temperature of primary recrystallization on the microstructure, texture and grain boundary characteristics of low-temperature Hi-B steel was studied by means of metallographic microscope, X-ray diffractometer and EBSD. The results show that the annealing temperature of the primary recrystallization directly affects the microstructure uniformity and the average grain size of the low-temperature Hi-B steel. With the increase of annealing temperature, the average grain size of the primary recrystallization structure increases from 15.2 μm to 26.7 μm, the primary recrystallization microstructure has the best uniformity after annealing at 820 ℃. The main texture types of primary recrystallization are: γ texture, α texture, {001}<120> texture and {114}<481> texture. When the annealing temperature rises to 880 ℃, the texture strength of {001}<120> increases obviously. With the increase of annealing temperature, the number of Goss grains decreases, area fraction of {114}<481> first decreases and then increases, while area fraction of {111}<112> begins to decrease after the annealing temperature rises to 840 ℃. When the annealing temperature is 800 ℃, the proportion of misorientation 20°-45° angle between {110}<001> grains and adjacent grains is the highest, which is 89.2%. The distribution of CSL grain boundaries around {110}<001> grains varies at different annealing temperatures.

Key words: annealing temperature, Hi-B steel, primary recrystallization, microstructure, texture