Vallourec Deutschland Gmbh

V&m Deutschland Gmbh

Charles Stallybrass

André Schneider

Joachim Konrad

Christoph Kaucke

Guido Kubla

Bernd Hahn

Heinz Sanders

Markus Schütz

A steel alloy with excellent creep strength and corrosion resistance that is ferritic at usage temperatures above 620&#xb0; C. has the following chemical composition (in wt. %): C&#x2266;1.0%; Si&#x2266;1.0%; Mn&#x2266;1.0%; P max. 0.05%; S max. 0.01%; 2&#x2266;Al&#x2266;12%; 3&#x2266;Cr&#x2266;16%; 2&#x2266;Ni&#x2266;10% and/or 2&#x2266;Co&#x2266;10%, where 2&#x2266;Ni+Co&#x2266;[% Cr]+2.07&#xd7;[% Al]&#x3e;=0.95&#xd7;([% Ni]+[% Co]); N max. 0.0200%. The remainder is iron with steel production-related impurities. Optionally, one or more elements of V, Ti, Ta, Zr, Nb, Mo and W, as well as one or more elements of Hf, B, Se, Y, Te, Sb, La and Zr with a cumulative content of &#x3c;0.1% can be added. The steel structure includes uniformly distributed coherent precipitates based on a chromium-stabilized (Ni, Co)Al&#x2014;B2 intermetallic ordered phase.

Steel alloy for ferritic steel having excellent creep strength and oxidation resistance at elevated usage temperatures

The invention relates to a steel alloy for a low alloy steel for producing high-tensile, weldable, hot-rolled seamless steel tubing, in particular construction tubing. The chemical composition (in % by mass) is: 0.15-0.18% C; 0.20-0.40% Si; 1.40-1.60% Mn; max. 0.05% P; max. 0.01% S; &#x3e;0.50-0.90% Cr; &#x3e;0.50-0.80% Mo; &#x3e;0.10-0.15% V; 0.60-1.00% W; 0.0130-0.0220% N; the remainder is made up of iron with production-related impurities; with the optional addition of one or more elements selected from Al, Ni, Nb, Ti, with the proviso that the relationship V/N has a value of between 4 and 12 and the Ni content of the steel is not more than 0.40%.

Steel alloy for a low-alloy steel for producing high-strength seamless steel tubing

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Düsseldorf, Germany

Charles Stallybrass