POSCO Holdings Inc.
STEEL PLATE FOR PRESSURE VESSEL HAVING EXCELLENT HYDROGEN INDUCED CRACKING RESISTANCE AND METHOD OF MANUFACTURING SAME

Abstract:

An embodiment of the present invention provides a steel plate for a pressure vessel having excellent hydrogen-induced cracking resistance and a method of manufacturing same, the steel plate comprising, in weight %, 0.2 to 0.3% of carbon (C), 0.05 to 0.50% of silicon (Si), 0.1% to 0.5% (exclusive) of manganese (Mn) , 0.005 to 0.1% of aluminum (Al), 0.010% or less of phosphorus (P) , 0.0015% or less of sulfur (S), 0.001 to 0.03% of niobium (Nb), 0.001 to 0.03% of vanadium (V) , 0.001 to 0.03% of titanium (Ti), 0.01 to 0.20% of chromium (Cr), 0.01 to 0.15% of molybdenum (Mo) , 0.01 to 0.50% of copper (Cu) , 0.05 to 0.50% of nickel (Ni), 0.0005 to 0.0040% of calcium (Ca), and the balance of Fe and other inevitable impurities, wherein the average grain size of ferrite is 5-20 .mu.m.