EXTRA-LOW CARBON HIGH-STRENGTH COLD-ROLLED STEEL PLATE WITH EXCELLENT FORMABILITY AND METHOD OF MANUFACTURING THE SAME CAPABLE OF RELATIVELY REDUCING TENSILE STRENGTH AND YIELD STRENGTH AFTER HOT ROLLING

摘要

PURPOSE: An extra-low carbon high-strength cold-rolled steel plate with excellent formability and a method of manufacturing the same are provided to enhance cold rolling performance and strength by relatively reducing yield strength and tensile strength after hot rolling.;CONSTITUTION: An extra-low carbon high-strength cold-rolled steel plate with excellent formability comprises carbon of 0.003~0.01 weight%, manganese of 0.01~0.3 weight%, sulfur of 0.005~0.01 weight%, aluminum of 0.01~0.1 weight%, nitrogen of 0.004~0.01 weight%, phosphorus of 0.05~0.1 weight%, boron of 0.0005~0.002 weight%, titanium of 0.02~0.06 weight%, molybdenum of 0.010~0.040 weight%, Fe and other inevitable impurities. The cold-rolled steel plate is cold-rolled annealed and then TiC precipitate and AIN precipitate are formed. The average size of the TiC precipitate and AIN precipitate is equal to 0.1μm or less.;COPYRIGHT KIPO 2012