POSCO Holdings Inc.
AUSTENITIC STAINLESS STEEL WITH IMPROVED RESISTANCE TO HYDROGEN BRITTLENESS AND VESSEL FOR HIGH PRESSURE HYDROGEN GAS HAVING THE SAME

Abstract:

An austenitic stainless steel improved in resistance to hydrogen brittleness and a vessel for high-pressure hydrogen gas are disclosed. The austenitic stainless steel according to one embodiment of the present invention includes by weight percent, 0.1% or less (excluding 0) of carbon(C), 1.0% or less (excluding 0) of silicon(Si), 2.0 to 7.0% of manganese(Mn), 15 to 25% of chromium (Cr), 7 to less than 10% of nickel (Ni), 0.4% or less (excluding 0) of nitrogen (N), and the remainder of iron (Fe) and other unavoidable impurities, and an SFE (stacking fault energy) of the austenite stainless steel is 40 to 70mJ/m.sup.2 defined by the following formula (1). SFE=4Ni+0.6Cr+7.7Mn-44.7Si+1.2 formula (1)