| abstract |
FIELD: metallurgy. n SUBSTANCE: invention relates to metallurgy. To increase the tensile strength and toughness at low temperatures, the hot-stamped part has a chemical composition, mass%: C 0.120–0.400, Si 0.005–2.000, Mn, or Cr, or both of them: in aggregate 1.00–3.00, Al 0.005–0.100, B 0.0003–0.0020, P is not more than 0.030, S is not more than 0.0100, O is not more than 0.0070, N is not more than 0.0070, Ti 0–0.100, Nb 0–0.100, V 0–0.100, Ni 0%–2.00, Cu 0–2.00, Mo 0–0.50, Ca, or rare earth metal (REM), or both of them: in aggregate 0–0.0300, Fe and impurities are the rest and the structure represented by: proportion of martensite, or bainite, or both of them: in aggregate not less than 95 %, the coefficient of coating the boundaries of the former austenite grains with iron-based carbides: not more than 80 %, and the numerical density of iron-based carbides in the former austenite grains: not less than 45/mcm 2 . n EFFECT: increasing tensile strength and toughness at low temperatures. n 5 cl, 1 dwg, 7 tbl |