2results about How to "High strength level" patented technology

This invention discloses a 440MPa grade steel plate with ultra-low temperature toughness and its preparation method, belonging to the field of steel materials technology. It solves the contradiction between insufficient strength and toughness grades and excessive nickel content in existing low-temperature steels. The composition of the 440MPa grade steel plate with ultra-low temperature toughness, by mass percentage, includes: C: 0.030%–0.085%, Si: 0.18%–0.38%, Mn: 0.95%–1.35%, P: ≤0.010%, S: ≤0.003%, Cr: 0.01%–0.25%, Mo: 0.01%–0.15%, Ni: 3.20%–4.25%, Cu: 0.12%–0.85%, Nb: 0.008%–0.035%, Al: 0.02%–0.036%, Ti: 0.008%–0.022%, with the balance being Fe and other unavoidable impurities. The steel plate of this invention exhibits excellent strength and low-temperature toughness.

The invention belongs to the field of steel, and particularly relates to super bainite steel and a preparation method thereof. The super bainite steel provided by the invention comprises the following chemical components in percentage by mass: 0.15 to 0.22 percent of C, 0.80 to 1.35 percent of Si, 1.8 to 2.3 percent of Mn, less than or equal to 0.01 percent of P, less than or equal to 0.005 percent of S, 0.01 to 0.12 percent of Als, 0.1 to 0.5 percent of Cr, 0.02 to 0.06 percent of Nb, 0.01 to 0.04 percent of Ti, less than or equal to 0.0045 percent of N and the balance of Fe and inevitable impurities, and meanwhile, Ceq is equal to C + Si / 30 + Mn / 20 + 2P + 4S < = 0.41. The super bainite steel provided by the invention is excellent in performance and can be widely applied to the field of automobile steel.