Refinement of the Grain Size of Steel by Alloy Partitioning Method

摘要

The present invention relates to a method to grain refine steel by alloying element distribution capable of improving low temperature toughness and strength of steel by refining the grain size of steel through distributing heat treatment of an alloying element. According to an embodiment of the present invention, provided is the method to grain refine steel by alloying element distribution comprising: step (a) of forming a lath martensite or bainite structure by cooling steel after the steel wherein substitutional alloy elements are added is heated at austenitic temperatures; step (b) of distributing the alloy elements by heating the alloy elements in a ferritic-austenitic two-phase region; and step (c) of cooling the alloy elements after the alloy elements are reheated at austenitic temperatures.