Abstract: By austenitizing at 810 ℃ for 1.5 min, furnace cooling to 500 ℃ and then air cooling, a rapid spheroidizing annealing process was carried out for 60Si2Mn cold drawn pearlite steel wire, then the mechanical properties, spheroidizing effect, spheroidizing time and rapid spheroidizing mechanism were studied and compared with that of normal spheroidizing annealing and isothermal spheroidizing annealing processes. The results show that compared with the two common spheroidizing annealing process, the rapid spheroidizing annealing process can significantly shorten the spheroidizing time, and with better spheroidizing effect. The yield strength, tensile strength, elongation and reduction of area of the rapid spheroidizing annealed steel are 620 MPa, 745 MPa, 21% and 66.7%, respectively. The shortening of spheroidizing time is mainly due to the increase of dislocation density and distortion energy in the steel caused by cold drawing deformation, which enables the lamellar pearlite to change rapidly into disconnected parts by dissolving in the heating process, and promotes the spheroidization of cementite.

Key words: rapid spheroidizing annealing, austenitization, pearlite, cementite