Sandvik Ab

Sandvik Intellectual Property Ab

Pasi Kangas

Johan Frodigh

Guocai Chai

Ulf Kivisäkk

Goran Berglund

Babak Bahar

Magnus Nystr&ouml;m

Anna Delblanc-Bauer

Bertil Walden

Michael Nicholls

&Ouml;rjan Bergstr&ouml;m

Mattias Klockars

A super-austenitic stainless steel alloy with a composition, balanced in such a way that products made from the alloy fulfill high requirements on a combination of high corrosion resistance, especially in inorganic and organic acids and mixtures thereof, good general corrosion resistance, good structure stability as well as improved mechanical properties in combination with good workability, in particular in tubes, especially seamless tubes and seam welded tubes for application in these environments and with following composition, in weight-percent: up to 2.0 of one or more element of the group Mg, Ce, Ca, B, La, Pr, Zr, Ti, Nd, and the balance being Fe and normally occurring impurities and steel making additions.

Super-austenitic stainless steel

The present invention relates to a duplex stainless steel alloy with austenite-ferrite structure, which in hot extruded and annealed finish shows high strength, good corrosion resistance, as well as good weldability which is characterized in that the alloy contains in weight-% max 0.05% C, 0-2.0% Si 0-3.0% Mn, 25-35% Cr, 4-10% Ni, 2-6% Mo, 0.3-0.6% N, as well as Fe and normally occurring impurities and additions, whereby the content of ferrite is 30-70%.

Duplex stainless steel

The invention relates to a ferrite-austenitic alloy and its use, the alloy has a composition with a mixture defined as: C maximum 0.05%, Si maximum 0.8%, Mn 0.30-1.5%, Cr 28.0-30.0%, Ni 5.80-7.40%, Mo 2.00-2.50%, N 0.30-0.40%, Cu maximum 1.0%, W maximum 2.0%, S maximum 0.010%, 30-70% ferrite and the balance austenite for tubes filled with hydraulic fluid, as transport tubes for solutions for chemical injection, or another uses in the application of umbilicals.

Use of stainless steel alloy as umbilical tubes in seawater environment

A duplex ferritic-austenitic stainless steel alloy provided for seawater applications includes, in weight %: C maximum 0.05; Si maximum 0.8; Mn 0.03-4; Cr 28-35; Ni 3-10%, Mo 1.0-4.0; N 0.2-0.6; Cu maximum 1.0; W maximum 2.0; S maximum 0.010; Ce maximum 0.2; and the balance Fe together with normally occurring impurities and additives, wherein the ferritic content is 30-70 volume %, the alloy composition has a PRE-value higher than 42, and the PRE-value is at least 40 in both the ferritic and austenitic phases. A method is also provided which includes: providing a duplex ferritic-austenitic stainless steel alloy with the above-noted composition, forming a component with the alloy, and contacting the component with seawater. In preferred embodiments, the component comprises at least one of tubes, bars, heavy castings, forging, plates, wire or strip.

Stainless steel for use in seawater applications

Ferritic-austenitic steel alloy

The invention relates to the use of a ferritic-austenitic stainless steel alloy as construction material for components in the process industry, which components can be foreseen to come into direct contact with caustic soda.

NaOH evaporator comprising at least one component formed by a high strength stainless steel

A duplex stainless steel alloy has been provided which contains in % by weight:

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Sandviken, Sweden

Pasi Kangas