Grains refinement,whichcansimultaneouslyenhancestrength
and toughnessofmaterials,isanimportantapproachindevel-
oping anewgenerationofhigh-performancematerials.Several
methods havebeendevelopedtoobtainultrafinegrainedsteels
through severeplasticdeformationandheattreatment [1–6].
Pearlite, consistingof a-Fe andlamellarcementite(y), isoneof
the mostimportantstructuresinsteels.Subtlecementiteparticles
are usedtorefinetheferritegrainsandform(aþy) micro-duplex
structures, whichcanenhancethepropertiesofpearlitesteels.
Therefore, thecoarseningbehaviorandsizecontrolofthe y
particles areveryimportantforobtainingthe(aþy) micro-
duplex structuresinsteels.Theconventionalspheroidization
process ofsteelconsistsofasubcriticalannealingtreatmentthat
takes alongtime [7–9]. Itisdifficulttoformultra-fineferrite
grains andsubtlecementiteparticlesinsteelsduringalong
period ofsubcriticalannealing.Generally,themostefficient
method ofobtainingsubtlecementiteparticlesinpearlitic
steels comprisesacombinationofseverecolddeformationand
annealing [1–3], heavywarmdeformation [4–6], andcyclicheat
treatment