Patent ID: 7534314

Claim:
A method for manufacture of components for motor vehicles, comprising: (a) forming density reducing high carbon steel, which contains, besides iron and conventional steel impurities, the following alloy components in wt. %: 0.8 to 2.5% C 8 to 15% Al 0.5 to 4% Cr 0.01 to 4% Si up to 5% Ni, Mn, Mo, Nb, Ta, V, and/or W 0.1 to 0.85 Sn and 0 to 3% Ti, Be and/or Ga; (b) melting the steel; (c) subjecting the steel to a targeted cooling process, which leads to a substantial two phase micro-structure with 65 to 85 vol. % α-Ferrite and 15 to 25 vol. % κ-carbide and cementite, whereby the steel exhibits a micro-structure with superplastic characteristics, and (d) deforming the steel to produce said component for said motor vehicle.