Effect of Strain Path on Texture and Microstructure of Cold Rolled Non-Oriented Electrical Steel

Abstract

Cross-Rolled Non-oriented (CRNO) electrical steel are distinguished by their uniformity in magnetic properties in all angular directions. However, constant research has been carried out to control the texture for uniform magnetic properties of these steels. In the present work the effect of strain-path and subsequent annealing of CRNO steels on their texture and microstructure have been investigated. Electrical steels are subjected to Unidirectional rolling, Cross-rolling and Reverse rolling and are subsequently annealed at 840°C for 1, 2 and 4 hrs. XRD and EBSD analysis is carried out for bulk and micro texture analysis respectively. It is observed that average grain size increased with increasing temperature and soaking time of annealing. The effect on Texture is best described by ratio of volume fraction of (111)/(001), which is generally termed as texture factor (tf) for nonoriented electrical steel. It is also observed that the volume fractions of various textures (111) fiber, (001) fiber, (110) fiber Goss orientation and cubic orientation do not show any change in trend with the annealing conditions. Hardness of the steel tends to decrease as annealing soaking time increases.