| 摘要 |
PURPOSE: A high-strength steel material with high toughness at very low temperatures and a manufacturing method thereof are provided to obtain a yield strength of 500MPa or greater and impact energy of 70J or greater at very low temperatures below -196°C. CONSTITUTION: A high-strength steel material with high toughness at very low temperatures comprises C(Carbon) of 0.01-0.06wt.%, Mn of 2.0-8.0wt.%, Ni of 0.01-6.0wt.%, Mo(Molybdenum) of 0.02-0.6wt.%, Si(Silicon) of 0.03-0.5wt.%, Al(Aluminum) of 0.003-0.05wt.%, N(Nitrogen) of 0.0015-0.01wt.%, P(Phosphorus) of 0.02wt.% or less, S(Sulfur) of 0.01wt.% or less, and Fe(Iron) and inevitable impurities of the remaining amount. |
