Analysis on tensile deformation and fracture behaviors of grain oriented electrical steels at low temperature

Tensile properties of grain-oriented electrical steels up to 300℃were investigated and the corresponding fractography characteristics were observed.It was found that the segregation of phosphor atoms on grain boundaries was decreased with increasing tensile temperature,which resulted in enhancing cleavage fractography with reducing intergranular fracture.The intergranular fracture disappeared at the temperature over 100℃,while the yield strength of the matrix became obviously lower than its cleavage strength,which led to reducing cleavage fractography with enhancing dimples fracture that prevailed at 190℃.The Cottrell atmosphere would be trailed by the moving dislocations during the tensile deformation between 100-160℃,which induced decreasing elongation and limited yield strength drop with increasing deformation temperature.