ECAP 공정에 의해 가공된 저탄소강의 구상화 거동

Abstract

The spheroidization behavior of low carbon steel processed by the equal channel angular pressing technique was investigated by imposing the static annealing treatment for 1 hour at various temperature of 693-973 K. By the repetitive pressings up to the accumulated effective strain of 4, the morphological change of cementite lamellar plates in pearlite was represented by the existence of either severely necked fragments parallel to each other or curled wavy fragments. Under the present annealing conditions, the microstructure of pearlite in pressed samples was characterized by the enhanced spheroidization of cementite compared to unpressed samples. The enhanced spheroidization behavior of the pearlite was discussed in terms of easy carbon dissolution from cementites into pearlitic ferrite due to the severe plastic deformation.