| 摘要 |
<p>A rustproof austenitic cast steel part having tensile strength greater than 550 MPA and elongation at break over 30%, is characterised in that the cast steel having an aluminium content of 0 to 4% and a silicon content of 1 to 4% is within an alloying range that is determined by the coordinates of four points (Crequiv.=14; Niequiv.=8), (Crequiv.=14; Niequiv.=14), (Crequiv.=22; Niequiv.=8) and (Crequiv.=22 Niequiv.=16), wherein the chromium and nickel equivalents are calculated from the chemical composition of a cast steel using the relations (1) and (2): Cr equiv . = % Cr + % Mo + 1.5 % Si + 0.5 % W + 0.9 % Nb + 4 % A 1 + 4 % Ti + 1.5 % V + 0 .9 % Ta ( 1 ) Ni equiv . = % Ni + 30 % C + 18 % N + 0.5 % Mn + 0.3 % Co + 0.2 % Cu - 0.2 % A 1 ( 2 ) wherein the figures must be quoted in mass percent and the remainder substantially comprises iron and other elements usually present in cast steel (O, P, S). Said cast steel exhibits a TRIP effect and serves as a material for plant and refrigeration engineering, particularly for facilities and components for obtaining gases and for liquefying and fractioning of gases, and as a material in the construction of special vehicles and airplanes for the transport of liquid gases and for components exposed to low temperatures, in addition to crash stressed castings.</p> |
