Krupp Vdm Gmbh

Vdm Nickel-technologie Aktiengesellschaft

Bayer Aktiengesellschaft

I.p. Bardin Central Research Institute of Iron & Steel

Michael Kohler

Ulrich Heubner

Ernst Wallis

Rolf Kirchheiner

Manfred Rockel

Kurt-Wilhelm Eichenhofer

Michael Renner

Kzasnykh V Ivanovich

Goronkova A Dmitrievna

Levin F Lvovich

The present invention relates to high chromium, corrosion resistant, austenitic alloys and to the use thereof.

Austenitic alloys and use thereof

The invention relates to an austenitic nickel-chromium-molybdenum alloy having high resistance to general corrosion, crevice, pitting and stress crack corrosion and also intercrystalline corrosion, consisting of (in % by weight):

Austenitic nickel alloy

The invention relates to a high-silicon-content corrosion-resistant austenitic steel, characterized by alloying contents (in % by weight) of

Austenitic steel

For use in making components which are required to have a very high resistance to uniform corrosion and against pitting and crevice corrosion under very highly corrosive conditions encountered in up to date chemical process technology and environmental protection technology, for instance, in flue gas desulfurizing plants for concentrating sulfuric acid, and which are required to be manufactured satisfactorily by conventional hot and cold forming processes an alloy is employed which contains (in % by weight) 22.0 to 24.0 chromium, 15.0 to 16.5 molybdenum, up to 0.3% tungsten, up to 1.5% iron, up to 0.4% vanadium, 0.1 to 0.4% aluminum, 0.001 to 0.04% magnesium and 0.001 to 0.01 calcium, balance nickel and inevitable accompanying elements and impurities.

Corrosion resistant hot and cold forming parts of Ni-Cr-Mo alloy and

Disclosed in an improvement in a known Ni-Cr-Fe alloy. The alloy of the invention contains 30 to 32% nickel; 26 to 28% chromium; 0.5 to 1.5% copper; 6 to 7% molybdenum; up to 2% manganese; up to 1.0% silicon; up to 0.2% aluminum; up to 0.03% carbon; 0.10 to 0.25% nitrogen; balance iron and usual impurities. The alloy of the invention has increased pitting corrosion potential and critical crevice corrosion and pitting corrosion temperatures whereas the resistance of the alloy to commercially pure phosphoric acid has not been decreased.

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Iserlohn, Germany

Michael Kohler