Patents by Inventor Mikko HEMMILÄ

Mikko HEMMILÄ has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230235425
    Abstract: A hot-rolled strip steel product is described having a chemical composition consisting of, in terms of weight percentages (wt. %): 0.030%-0.10% C, 0%-1.10% Si, 0.50%-2.0% Mn, <0.020% P, <0.010% S,<0.010% N, 0%-0.60% Cr, 0%-0.20% Ni, 0%-0.25% Cu, 0%-0.30% Mo, 0%-0.15% Al, 0%-0.10% Nb, 0.10%-0.30% V, <0.020% Ti, 0%-0.0010% B, remainder being Fe and inevitable impurities, wherein the hot rolled strip steel product has a a microstructure comprising, in terms of volume percentages (vol. %), ferrite?90, wherein the ferrite structure comprises bainite, at least 50% of polygonal ferrite and at most 10% quasi-polygonal ferrite, and wherein the steel strip product has an average hole expansion ratio?50%, a yield strength (Rp0.2%) longitudinal to rolling direction of ?660 MPa and a tensile strength?760 MPa.
    Type: Application
    Filed: May 20, 2021
    Publication date: July 27, 2023
    Inventors: Vili Kesti, Ari Hirvi, Tommi Liimatainen, Mikko Hemmilä, Pasi Suikkanen, Erik Nymann, Martin Lind, Robin Nilsson, Juha Pyykkönen
  • Publication number: 20230235420
    Abstract: A hot-rolled strip steel product having a chemical composition consisting of, in terms of weight percentages (wt. %): 0.025%-0.070% C, 0%-1.10% Si, 0.50%-2.0% Mn, <0.020% P, <0.050% S, <0.010% N, 0%-0.60% Cr, 0%-0.20% Ni, 0%-0.25% Cu, 0%-0.20% Mo, 0%-0.15% Al, 0%-0.050% Nb, 0.020%-0.20-% V, 0.020%-0.15% Ti, 0%-0.0010% B, remainder Fe and inevitable impurities, wherein the strip steel product has a microstructure comprising of, in terms of volume percentages (vol. %), ferrite ?90%, wherein the ferrite structure comprises 10%-50% quasi-polygonal ferrite and a reminder of ferrite structure is polygonal ferrite and/or bainite: and wherein the steel strip product has an average ferrite grain size of <10 ?m, an average hole expansion ratio of ?50%, a yield strength (Rp0.2%) longitudinal to rolling direction of ?660 MPa and a tensile strength of ?760 MPa.
    Type: Application
    Filed: May 20, 2021
    Publication date: July 27, 2023
    Inventors: Vili Kesti, Tommi Liimatainen, Mikko Hemmilä, Pasi Suikkanen, Erik Nymann, Martin Lind, Robin Nilsson, Juha Pyykkönen
  • Publication number: 20230203609
    Abstract: A hot-rolled steel is described having a yield strength (Rp0.2) of at least 1100 MPa along and/or transverse to a rolling direction which has a chemical composition of (in mass-%): C: 0.10-0.2, Si: 0-0.7, Mn: 1.1-2.2, Nb: 0-0.06, Ti: 0-0.15, V: more than 0.03 and ?0.25, Al: 0.01-0.15, B: 0.0005-0.010, Cr: 0.1-1.7, Mo: 0.15-0.8, Cu: 0-1.5, Ni: 0.3-2.5, P: 0-0.015, S: 0-0.008 Zr: 0-0.2, Ca: 0-0.004, the balance Fe and unavoidable impurities, whereby a) when 0.1<C<0.11 then Mn?1.6 and V>0.14 and Mo?0.5 (in mass-%), b) when 0.11?C<0.125 then Mn?1.45 and V?0.13 and Mo?0.35 (in mass-%), c) when 0.125?C<0.15, then Mn?1.35 and V?0.12 and Mo?0.20 (in mass-%), and d) when C?0.15 and V>0.11, then Mn?1.3 and Mo?0.15 (in mass-%) or when C?0.15 and V 0.03-0.11, then Mn>1.3 and Mo>0.15 and Nb>0.02 and Cr+Cu+Ni>1.4 (in mass-%).
    Type: Application
    Filed: January 16, 2019
    Publication date: June 29, 2023
    Inventors: Tommi Liimatainen, Mikko Hemmilä, Ari Hirvi, Teijo Limnell, Tuomo Saarinen, Tuomas Antola, Pasi Lehtikangas, Sakari Tihinen, Vili Kesti, Saija Martinmäki
  • Patent number: 11572603
    Abstract: Disclosed is a hot-rolled steel strip having a tensile strength greater than 875 MPa and containing in mass-%: C 0.06-0.12, Si 0-0.5, Mn 0.70-2.20, Nb 0.005-0.100, Ti 0.01-0.10, V 0.11-0.40, whereby the total amount of V+Nb+Ti is 0.20-0.40 Al 0.005-0.150, B 0-0.0008, Cr 0-1.0, whereby the total amount of Mn+Cr is 0.9-2.5, Mo 0-0.5, Cu 0-0.5, Ni 0-1.0, P 0-0.05, S 0-0.01, Zr 0-0.1 Co 0-0.1 W 0-0.1 Ca 0-0.005, N 0-0.01, balance Fe and unavoidable impurities, and having a microstructure at ¼ thickness that is: at least 90% martensite and bainite with island-shaped martensite-austenite (MA) constituents, the remainder being: less than 5% polygonal ferrite and quasi-polygonal ferrite, less than 5% pearlite, less than 5% austenite, so that the total area percentage is 100%.
    Type: Grant
    Filed: November 13, 2019
    Date of Patent: February 7, 2023
    Assignee: SSAB TECHNOLOGY AB
    Inventors: Mikko Hemmilä, Tommi Liimatainen, Ari Hirvi
  • Publication number: 20220177996
    Abstract: Described is a hot-rolled steel strip product that includes a composition consisting of, in terms of weight percentages, 0.17% to 0.38% C, 0% to 0.5% Si, 0.1% to 0.4% Mn, 0.015% to 0.15% Al, 0.1% to 0.6% Cu, 0.2% to 0.8% Ni, 0.1% to 1% Cr, 0.01% to 0.3% Mo, 0% to 0.005% Nb, 0% to 0.05% Ti, 0% to 0.2% V, 0.0008% to 0.005% B, 0% to 0.025% P, 0.008% or less S, 0.01% or less N, 0% to 0.01% Ca, and the remainder being Fe and inevitable impurities, wherein the steel product has a Brinell hardness in the range of 420-580 HBW, and a corrosion index (ASTM G101-04) of at least 5.
    Type: Application
    Filed: April 2, 2020
    Publication date: June 9, 2022
    Inventors: Mikko Hemmilä, Tommi Liimatainen, Esa Virolainen, Pasi Suikkanen, Magnus Larsson, Magnus Gladh
  • Publication number: 20220177997
    Abstract: Described is a hot-rolled steel strip product including a composition consisting of, in terms of weight percentages, 0.14% to 0.35% C, 0% to 0.5% Si, 0.05% to 0.40% Mn, 0.1% or less Al, 0.1% to 0.4% Cu, 0.2% to 0.9% Ni, 0.2% to 0.9% Cr, 0.2% or less Mo, 0.005% or less Nb, 0.035% or less Ti, 0.05% or less V, 0.0005% to 0.0050% B, 0.025% or less P, 0.008% or less S, 0.01% or less N, 0.01% or less Ca, and the remainder being Fe and inevitable impurities, wherein the steel product has a Brinell hardness in the range of 420 to 580 HBW.
    Type: Application
    Filed: April 2, 2020
    Publication date: June 9, 2022
    Inventors: Magnus Larsson, Magnus Gladh, Mikko Hemmilä, Tommi Liimatainen, Esa Virolainen, Pasi Suikkanen
  • Publication number: 20220002836
    Abstract: Disclosed is a hot-rolled steel strip having a tensile strength greater than 875 MPa and containing in mass-%: C 0.06-0.12, Si 0-0.5, Mn 0.70-2.20, Nb 0.005-0.100, Ti 0.01-0.10, V 0.11-0.40, whereby the total amount of V+Nb+Ti is 0.20-0.40 Al 0.005-0.150, B 0-0.0008, Cr 0-1.0, whereby the total amount of Mn+Cr is 0.9-2.5, Mo 0-0.5, Cu 0-0.5, Ni 0-1.0, P 0-0.05, S 0-0.01, Zr 0-0.1 Co 0-0.1 W 0-0.1 Ca 0-0.005, N 0-0.01, balance Fe and unavoidable impurities, and having a microstructure at ¼ thickness that is: at least 90% martensite and bainite with island-shaped martensite-austenite (MA) constituents, the remainder being: less than 5% polygonal ferrite and quasi-polygonal ferrite, less than 5% pearlite, less than 5% austenite, so that the total area percentage is 100%.
    Type: Application
    Filed: November 13, 2019
    Publication date: January 6, 2022
    Inventors: Mikko Hemmilä, Tommi Liimatainen, Ari Hirvi
  • Patent number: 10837079
    Abstract: 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: Grant
    Filed: January 23, 2015
    Date of Patent: November 17, 2020
    Assignee: RAUTARUUKKI OYJ
    Inventors: Tommi Liimatainen, Mikko Hemmilä, Pasi Suikkanen, Juha Erkkilä, Kati Rytinki, Tuomo Saarinen, Teijo Limnell
  • Publication number: 20160333440
    Abstract: 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: Application
    Filed: January 23, 2015
    Publication date: November 17, 2016
    Inventors: Tommi LIIMATAINEN, Mikko HEMMILÄ, Pasi SUIKKANEN, Juha ERKKILÄ, Kati RYTINKI, Tuomo SAARINEN, Teijo LIMNELL