FINE SPHEROIDAL GRAPHITE STEEL SHEET WITH EXCELLENT HEAT TREATMENT PROPERTY AND A MANUFACTURING METHOD THEREOF TO LOWER THE ANNEALING TEMPERATURE AND REDUCE THE ANNEALING TIME

摘要

PURPOSE: A fine spheroidal graphite steel sheet with excellent heat treatment property and a manufacturing method thereof are provided to reduce the number of manufacturing processes by carrying out cold rolling directly after hot rolling, excluding spheroidizing.;CONSTITUTION: A fine spheroidal graphite steel sheet with excellent heat treatment property comprises C 0.3~1.0 weight%, Mn 0.1~1.2 weight%, Si 0~0.4 weight% or less, Al 0.01~0.1 weight%, S 0~0.01 weight% or less, and the rest Fe and inevitable impurities. The fine spheroidal graphite steel sheet has a fine perlite structure in which the lamellar interval of cementite is 1.0μm or less at the room temperature after hot rolling.;COPYRIGHT KIPO 2010