Microstructure and Mechanical Properties of Pearlite Steel Wire with Large Deformation

The microstructure of SWRH72A steel wire before and after large drawing deformation was analyzed by TEM.Changes of the pearlite interlamellar spacing and mechanical properties with the drawing strain were studied.The results indicate that with the increase of strain,the strength of the steel wire increased,but elongation first decreased sharply and then remained unchanged.The pearlite interlamellar spacing of the steel wire decreased with the increase of strain,and it changed from 200 nm to 50 nm when the drawing strain ε=2.6,which was basically followed exponential decay law of Landford.The dislocation density in ferrite lamellar significantly increased after large deformation,formed a lot of dislocation cells,and the ferrite changed into a special orientation.