Thyssenkrupp Steel Europe Ag

Thyssen Krupp Ag

Evonik Operations Gmbh

Rainer Fechte-Heinen

Lothar Patberg

Stephan Drewes

Erik Hilfrich

Konstantinos Savvas

Mark Hirt

Jens-Ulrik Becker

Andreas Kern

Andreas Cott

Thomas Flaskamp

Adrian Paton

Christian Höckling

Stefan Mayer

Richard Georg Thiessen

Thomas Gerber

Vanessa Wieschalla

Joseph Georg Kevenhörster

Ingo Thomas

Manuela Irnich

Jens Horstmann

Hasan Bagci

Miriam Lange

Bernd Linke

Jan-Hendrik Rudolph

Kai Uwe Jentsch

Nicholas Winzer

Tim Stötzel

Thomas Niessen

Branko Kuchar

Andreas Offergeld

Christian HÖCKLING

The present invention relates to a flat steel product which has good deep-drawing ability, low edge-crack sensitivity and good bending behaviour. To this end, the flat steel product contains a steel which consists of (in wt %) 0.1-0.5% C, 1.0-3.0% Mn, 0.9-1.5% Si, up to 1.5% Al, up to 0.008% N, up to 0.020% P, up to 0.005% S, 0.01-1% Cr and optionally one or more of the following elements: up to 0.2% Mo, up to 0.01% B, up to 0.5% Cu, up to 0.5% Ni and optionally a total of 0.005-0.2% microalloying elements, the remainder being iron and unavoidable impurities, wherein 75&#x3c;(Mn2+55*Cr)/Cr&#x3c;3000 where Mn is the Mn content of the steel in wt % and Cr is the Cr content of the steel in wt %. The steel has a structure which consists of at least 80 area % martensite, of which at least 75 area % is tempered martensite and at most 25 area % is non-tempered martensite, at least 5 volume % residual austenite, 0.5 to 10 area % ferrite and at most 5 area % bainite, wherein in the region of the phase boundary between tempered martensite and residual austenite there is a low-Mn ferrite seam which has a width of at least 4 nm and at most 12 nm and the Mn content of which is at most 50% of the average Mn content of the flat steel product. The flat steel product contains carbides with a length of less than or equal to 250 nm. The invention also relates to a method for producing a flat steel product according to the invention, in which method the structural characteristics of the flat steel product according to the invention are set by suitable heat treatment.

Flat steel product and method for producing same

A hot-rolled flat steel product including (in wt %) C: 0.1-0.3%, Mn: 1.5-3.0%, Si: 0.5-1.8%, Al: &#x2264;1.5%, P: &#x2264;0.1%, S: &#x2264;0.03%, N: &#x2264;0.008%, optionally one or more of Cr: 0.1-0.3%, Mo: 0.05-0.25%, Ni: 0.05-2.0%, Nb: 0.01-0.06%, Ti: 0.02-0.07%, V: 0.1-0.3%, and B: 0.0008-0.0020%, the balance being iron and unavoidable impurities. This flat steel product possesses a tensile strength of 800-1500 MPa, a yield strength of &#x3e;700 MPa, an elongation at break of 7-25%, and a hole expansion of more than 20%. The structure is at least 85 area % martensite, of which at least half is tempered martensite, with the remainder being &#x2264;15 vol % residual austenite, &#x2264;15 area % bainite, &#x2264;15 area % polygonal ferrite, &#x2264;5 area % cementite and/or &#x2264;5 area % nonpolygonal ferrite, and has a kernel average misorientation of at least 1.50&#xb0;. Also, a method for producing the flat steel product, wherein the microstructure of the flat steel product is set by the heat treatment.

Hot-rolled flat steel product and method for the production thereof

Methods for producing a flat product from an iron-based shape memory alloy may involve casting a melt comprised of iron, alloying elements, and impurities into a strip having a thickness of 1-30 mm and cooling the melt as the strip is formed. A twin-roll caster may be employed to help cool and form the melt into the strip. The resultant flat product is highly resistant to bending and is robust under pressure and torsion.

Method for producing a flat product from an iron-based shape memory alloy

The invention relates to a tower of a wind power plant, having a lower part in the form of a lattice tower or truss tower with at least two corner bars, and an upper part in the form of a cross-sectionally substantially round tubular tower, wherein each particular corner bar is put together from a plurality of steel tube profiles that are connected together in the longitudinal direction. In order to achieve good transportability and easier assembly of the components of such a tower, the invention proposes a modular tower concept. According to the invention, each particular corner bar is in this case put together from at least three steel tube profiles which are provided with perforated flanges for holding screws, wherein the corner bars are connected together by cross struts and/or tension struts attached to the flanges, and wherein the steel tube profiles of each particular corner bar are spirally welded steel tube profiles.

Modular tower for a wind power plant

A connector is disclosed for providing a positive and/or a non-positive connection between at least two connecting partners. The connector or connecting means has at least one first region which engages with the first connecting partner by way of a positive and/or a non-positive connection, and at least one second region is provided which engages with the at least second connecting partner by way of a positive and/or a non-positive connection. The connecting means provides a positive and/or non-positive connection between at least two connecting partners in a simple and inexpensive manner and which meets high safety requirements. The second region of the connecting means has a region which is formed from an at least partially flat material made of an Fe alloy with shape memory characteristics and which, when activated, ensures the positive and/or non-positive connection with the second connecting partner by way of a change in shape.

Connection means with shape memory

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Bottrop, Germany

Rainer Fechte-Heinen