Effect of deformation on the mechanical properties of a microalloyed medium carbon steel

The hot deformation behavior and the microstructure evolution of a microalloyed medium carbon steel was investigated by uniaxial hot compression. The microstructural parameters, such as ferrite grain size (d), interlamellar spacing (S), pearlite colony size (p), were measured and their contributions to strength and toughness were calculated. It was found that the strength of the steel used was mainly controlled by pearlite content and interlamellar spacing, whereas its toughness was mainly affected by ferrite content and pearlite colony. Suitable forging deformation could accelerate ferrite nucleation and increase its content, and therefore could improve its toughness.