Abstract: The invention relates to an austenitic nickel/chrome/cobalt/molybdenum/tungsten alloy, comprising (in mass %): carbon: 0.05 to 0.10%; chromium: 21 to 23%; cobalt: 10 to 15%; molybdenum: 10 to 11%; aluminium: 1.0 to 1.5%; tungsten: 5.1 to 8.0%; yttrium: 0.01 to 0.10%; boron: 0.001 to 0.010%; titanium: max. 0.50%; silicon: max. 0.50%; iron: max. 2%; manganese: max. 0.5%; nickel: remainder; including unavoidable impurities caused by the smelting process.

Abstract: The invention relates to an austenitic-chromium-iron alloy and its use as a material for articles with high resistance to isothermal and cyclic high temperature oxidation, high heat-resistance and high creep rupture strength at temperatures above 1100 to 1200.degree. C. The characterizing feature of the invention is that the austenitic nickel-chromium-iron alloy consists (in % by weight) of:______________________________________ 0.12 to 0.30% carbon 23 to 30% chromium 8 to 11% iron 1.8 to 2.4% aluminium 0.01 to 0.15% yttrium 0.01 to 1.0% titanium 0.01 to 1.0% niobium 0.01 to 0.20% zirconium 0.001 to 0.015% magnesium 0.001 to 0.010% calcium max 0.030% nitrogen max 0.50% silicon max 0.25% manganese max 0.020% phosphorus max 0.010% sulphur ______________________________________residue nickel, including unavoidable impurities caused by melting.

Abstract: An austenitic carbide-strengthened nickel/chromium/iron foregeable alloy comprises (in % by weight) 0.2 to 0.4% carbon, 25 to 30% chromium, 8 to 11% iron, more than 2.4 to 3.0% aluminum, 0.01 to 0.15% yttrium, 0.01 to 0.20% titanium, 0.01 to 0.20% niobium, 0.01 to 0.10% zirconium, 0.001 to 0.015% magnesium, 0.001 to 0.010% calcium, max 0.030% nitrogen, max 0.50% silicon, max 0.25% manganese, max 0.020% phosphorus, max 0.010% sulfur, balance nickel and unavoidable melting conditioned impurities. The quantity of precipitable carbon C* is in the range 0.083% to 0.300%, where C*=C.sub.tot. -(C.sub.diss. +C.sub.fix.Ti +C.sub.fix.Nb +C.sub.fix.Zr).

Abstract: The invention relates to a heat resistant hot formable austenitic nickel alloy consisting of (in % by weight)______________________________________ carbon 0.05 to 0.15 silicon 2.5 to 3.0 manganese 0.2 to 0.5 phosphorus max 0.015 sulphur max 0.005 chromium 25 to 30 iron 20 to 27 aluminium 0.05 to 0.15 calcium 0.001 to 0.005 rare earths 0.05 to 0.15 nitrogen 0.05 to 0.20 ______________________________________residue nickel and the usual impurities due to melting.

Abstract: The invention relates to a heat resistant hot formable austenitic steel consisting of (in % by weight)______________________________________ carbon 0.10 to 0.20 silicon 2.5 to 3.0 manganese 0.2 to 0.5 phosphorus max 0.015 sulphur max 0.005 chromium 25 to 30 nickel 30 to 35 aluminium 0.05 to 0.15 calcium 0.001 to 0.005 rare earths 0.05 to 0.15 nitrogen 0.05 to 0.20 ______________________________________residue iron and the usual impurities due to melting.

Abstract: A heat-deformable, austenitic nickel-chromium-iron alloy with high oxidation resistance and thermal strength, comprises17 up to 25 % Fe14 up to 20 % Cr0.5 up to 2.0 % Si0.1 up to 2.0 % Mn0.04 up to 0.10 % C0.02 up to 0.10 % Ca0.010 up to 0.080 % N0.025 up to 0.045 % Ti0.04 up to 0.17 % Zr0.03 up to 0.08 % Yless than 0.010 % Sless than 0.015 % Peach less than 0.1 % Mo, W, Coeach less than 0.05 % Nb, Ta, Al, V, Curest Niwith the feature, that the nitrogen content is adjusted in accordance with the following formula:% N=(0.15 up to 0.30).times.% Zr+(0.30 up to 0.60).times.% Ti.