Study on Ferrite Transformation Obtained by Dynamic Transformation of Undercooled Austenite of Low Carbon Steel

The ferrite transformation and its peculiarities based on dynamic transformation of undercooled austenite(DTUA) were investigated by uniaxial hot compression tests on Gleeble1500 simulation test machine.The results show that the grain size of ferrite is refined to 2～3 μm through DTUA.Moreover,the addition of Al can accelerate the transformation of γ→α during DTUA.Except the diffusion of C takes place,substitutional elements can not diffuse during DTUA.The high concentration of substitutional elements in ferrite results in distorting lattice of ferrite and thus the diffraction peaks of ferrite deviate to little angle.