Patents Assigned to Rautaruukki Oyj
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Patent number: 10837079Abstract: The present invention relates to thin hot-rolled ultrahigh strength steel (UHSS) products, i.e. to hot-rolled steel strips with ultrahigh strength and good bendability. The object of the present invention is to provide an ultrahigh strength hot-rolled steel product that is having yield strength Rp0.2 at least 840 MPa and improved bendability. Further, a preferred aim is also to achieve an ultrahigh strength steel strip with excellent low temperature impact toughness. The inventors of the present invention have surprisingly found that the bendability of directly quenched ultrahigh strength steel strip can be significantly improved by producing a microstructure comprising upper bainite as main phase and by having a hot-rolled steel strip product having a yield strength Rp0.2 at least 840 MPa and a thickness of less than 12 mm, whose composition in percentage by weight is C: 0.03-0.08, Si: 0.01-0.8, Mn: 0.8-2.5, Al: 0.01-0.15, Cr: 0.01-2.0, B: 0.0005-0.005 Nb: 0.005-0.07, Ti: 0.005-0.12, N:<0.01, P:<0.Type: GrantFiled: January 23, 2015Date of Patent: November 17, 2020Assignee: RAUTARUUKKI OYJInventors: Tommi Liimatainen, Mikko Hemmilä, Pasi Suikkanen, Juha Erkkilä, Kati Rytinki, Tuomo Saarinen, Teijo Limnell
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Patent number: 10577671Abstract: There is disclosed a method of manufacturing a hot-rolled steel product, such as a hot-rolled steel strip or plate product, wherein the microstructure of the steel product is martensitic, having Brinell hardness of at least 450 HBW. The method comprises the following steps in given sequence: a step of providing a steel slab containing, in terms of weight percentages, C: 0.25-0.45%, Si: 0.01-1.5%, Mn: 0.4-3.0%, Ni: 0.5-4.0%, Al: 0.01-1.2%, Cr: less than 2.0%, Mo: less than 1.0%, Cu: less than 1.5%, V: less than 0.5%, Nb: less than 0.2%, Ti: less than 0.2%, B: less than 0.01%, Ca: less than 0.01%, the balance being iron, residual contents and unavoidable impurities; a heating step of heating the steel slab to a temperature Theat in the range 950-1350° C.; a temperature equalizing step; a hot-rolling step in a temperature range of Ar3 to 1300° C. to obtain a hot-rolled steel material; and a step of direct quenching the hot-rolled steel material from the hot-rolling heat to a temperature of less than Ms.Type: GrantFiled: August 28, 2014Date of Patent: March 3, 2020Assignee: RAUTARUUKKI OYJInventors: Pasi Suikkanen, Mikko Hemmila, Visa Lang, Iikka Miettunen, Olli Oja
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Patent number: 9567659Abstract: The invention relates to a method for manufacturing a high-strength structural steel and to a high-strength structural steel product. The method comprises a providing step for providing a steel slab, a heating step (1) for heating said steel slab to 950 to 1300 C, a temperature equalizing step (2) for equalizing the temperature of the steel slab, a hot rolling step including a hot rolling stage of type I (5) for hot rolling the steel slab in the no-recrystallization temperature range below the recrystallization stop temperature (RST) but above the ferrite formation temperature A3, a quenching step (6) for quenching said hot-rolled steel at cooling rate of at least 20 C/s to a quenching-stop temperature (QT) between Ms and Mf temperatures, a partitioning treatment step (7, 9) for partitioning said hot-rolled steel in order to transfer carbon from martensite to austenite, and a cooling step (8) for cooling said hot-rolled steel to room temperature.Type: GrantFiled: July 2, 2012Date of Patent: February 14, 2017Assignee: RAUTARUUKKI OYJInventors: Mahesh Chandra Somani, David Arthur Porter, Leo Pentti Karjalainen, Tero Tapio Rasmus, Ari Mikael Hirvi
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Publication number: 20160208352Abstract: There is disclosed a method of manufacturing a hot-rolled steel product, such as a hot-rolled steel strip or plate product, wherein the microstructure of the steel product is martensitic, having Brinell hardness of at least 450 HBW. The method comprises the following steps in given sequence: a step of providing a steel slab containing, in terms of weight percentages, C: 0.25-0.45%, Si: 0.01-1.5%, Mn: 0.4-3.0%, Ni: 0.5-4.0%, Al: 0.01-1.2%, Cr: less than 2.0%, Mo: less than 1.0%, Cu: less than 1.5%, V: less than 0.5%, Nb: less than 0.2%, Ti: less than 0.2%, B: less than 0.01%, Ca: less than 0.01%, the balance being iron, residual contents and unavoidable impurities; a heating step of heating the steel slab to a temperature Theat in the range 950-1350° C.; a temperature equalizing step; a hot-rolling step in a temperature range of Ar3 to 1300° C. to obtain a hot-rolled steel material; and a step of direct quenching the hot-rolled steel material from the hot-rolling heat to a temperature of less than Ms.Type: ApplicationFiled: August 28, 2014Publication date: July 21, 2016Applicant: RAUTARUUKKI OYJInventors: Pasi Suikkanen, Mikko Hemmila, Visa Lang, Iikka Miettunen
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Publication number: 20140299237Abstract: The invention relates to a method for manufacturing a high-strength structural steel and to a high-strength structural steel product. The method comprises a providing step for providing a steel slab, a heating step (1) for heating said steel slab to 950 to 1300 C, a temperature equalizing step (2) for equalizing the temperature of the steel slab, a hot rolling step including a hot rolling stage of type I (5) for hot rolling the steel slab in the no-recrystallization temperature range below the recrystallization stop temperature (RST) but above the ferrite formation temperature A3, a quenching step (6) for quenching said hot-rolled steel at cooling rate of at least 20 C/s to a quenching-stop temperature (QT) between Ms and Mf temperatures, a partitioning treatment step (7, 9) for partitioning said hot-rolled steel in order to transfer carbon from martensite to austenite, and a cooling step (8) for cooling said hot-rolled steel to room temperature.Type: ApplicationFiled: July 2, 2012Publication date: October 9, 2014Applicant: RAUTARUUKKI OYJInventors: Mahesh Chandra Somani, David Arthur Porter, Leo Pentti Karjalainen, Tero Tapio Rasmus, Ari Mikael Hirvi
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Patent number: 8806827Abstract: A shaped roof element (1) for roofs made of elements, the roof element (1) comprising a first and a second side edge (4, 6), an upper edge (8) and a lower edge (10), a profile substantially parallel to the side edges (4, 6) and a series of steps comprising two or more steps (12, 14) extending substantially parallel to the upper and lower edges (8, 10), the steps being produced so that the lower edge (10) forms one of the steps (14). The step (14) on the lower edge (10) is produced in the form of a round bend (20) bending underneath the shaped roof element (1), the profile of the bend corresponding substantially to a profile parallel to the side edges (4, 6) of the shaped roof element (1).Type: GrantFiled: October 30, 2008Date of Patent: August 19, 2014Assignee: Rautaruukki OyjInventors: Matti Perttula, Janne Tanhuanpää
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Patent number: 8603428Abstract: The present invention concerns a method for producing calcium carbonate containing the steps of extraction of alkaline industrial waste or by-products using as a first extraction solvent an aqueous solution of a salt formed from a weak acid and a weak base, whereby a vanadium-enriched first residue is allowed to settle and a calcium-rich first filtrate is formed, filtration, whereby the first filtrate is separated from the first residue, carbonation of the calcium-rich first filtrate using a carbonation gas, whereby calcium carbonate precipitates and a second filtrate is formed, and a second filtration, whereby the calcium carbonate is separated from the second filtrate. Further, the present invention concerns a method for extracting calcium carbonate and vanadium from alkaline industrial waste or by-products.Type: GrantFiled: May 29, 2009Date of Patent: December 10, 2013Assignees: Aalto University Foundation, Abo Akademi, Rautaruukki OyjInventors: Sebastian Teir, Sanni Eloneva, Hannu Revitzer, Ron Zevenhoven, Justin Salminen, Carl-Johan Fogelholm, Esko Poylio
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Patent number: 8522502Abstract: Tower structures of wind power installations having a height of more than 80 meters have a mast structure with corner posts composed of sub-profiles. The corner posts are each formed a sub-profile A and a sub-profile I which are not integrally connected to one another. The sub-profiles together form a closed overall profile. Separating joints of the closed overall profile are arranged aligned with corresponding separating joints of an adjacent corner post which is connected to struts.Type: GrantFiled: August 22, 2008Date of Patent: September 3, 2013Assignee: Rautaruukki OyjInventor: Klaus Huesemann
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Patent number: 8474212Abstract: The invention relates to a tower for a wind power plant having a plurality of corner bars (1) for forming a mast construction, wherein the corner bars (1) are each made up of a plurality of partial profiles (2) connected to each other and having opposing connection areas (3a, 3b) at which the adjacent partial profiles (2) of a corner bar (1) can be connected to each other, and wherein the partial profiles (2) each have two kink points in cross section extending in the longitudinal direction of the partial profiles (2) in a segment located between opposite connection areas (3a, 3b) of the partial profile.Type: GrantFiled: April 22, 2009Date of Patent: July 2, 2013Assignee: Rautaruukki OyjInventors: Klaus Husemann, Willi Meiners