Abstract: The characteristics and influencing factors of iron loss distribution along rolling direction and transverse direction of large width oriented silicon steel coil were studied. The results showed that the iron loss along both the rolling direction and the transverse direction had obvious nonuniform distribution characteristics.The maximum iron loss along the rolling direction and the transverse direction both occurred in the innermost circle area and the area where the cold spot was located.With the changing position along the rolling direction, both the maximum and minimum iron losses along the transverse direction fluctuated, resulting in the fluctuation value of the transverse iron loss being closely related to the position along the rolling direction.It was concluded that the characteristics of iron loss distribution along the rolling direction and transverse direction of large width oriented silicon steel coil were mainly related to the non-uniform distribution of temperature field during high temperature annealing. The non-uniform distribution of temperature field resulted in significant differences in the secondary recrystallization process and purification annealing effect at different positions of oriented silicon steel coil.On the one hand, the secondary recrystallization grain size in the innermost ring and cold spot region of oriented silicon steel coil was significantly smaller than that in the outermost ring region, and the residual island grain in the innermost ring and cold spot region showed a gradient distribution along the transverse direction, while there was almost no island grain in the outermost ring region. On the other hand, the distribution gradient of N content in the innermost ring and cold spot region along the transverse direction was obviously larger than that in the outermost ring region.

Key words: grain-oriented silicon steel, high temperature annealing, temperature field, secondary recrystallization, iron loss