HIGH STRENGTH STEEL SHEET FOR A PRESSURE VESSEL WITH EXCELLENT HIC AND FATIGUE RESIST PROPERTIES AND A MANUFACTURING METHOD THEREOF, CAPABLE OF CONTROLLING THE BANDING INDEX OF MICRO-STRUCTURE

摘要

PURPOSE: A high strength steel sheet for a pressure vessel with excellent HIC and fatigue resist properties and a manufacturing method thereof are provided to fatigue property and improve tensile strength by adding Ti and N.;CONSTITUTION: A high strength steel sheet for a pressure vessel comprises C 0.10~0.30 weight%, Si 0.15~0.40 weight%, Mn 0.6~1.2 weight%, Al 0.001~0.05 weight%, P 0.035 weight% or less, S 0.020 weight% or less, Cr 0.35 weight% or less, Mo 0.2 weight% or less, Ni 0.5 weight% or less, V 0.05 weight% or less, Nb 0.05 weight% or less, Ca 5~50ppm, Ti 0.005~0.025 weight%, N 0.0020~0.0060 weight%, and the rest including Fe and inevitable impurities. Cu+Ni+Cr+Mo are included less than 1.5 weight%. Cr+Mo are included less than 0.4 weight%. V+Nb are included less than 0.1 weight%.;COPYRIGHT KIPO 2010