Patents by Inventor Manfred Espenhahn

Manfred Espenhahn 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).

  • Patent number: 6524400
    Abstract: A process for the production of grain-oriented electric quality sheet by melting a silicon steel and casting the melt continuously into a strand having a thickness of 25-100 mm. During solidification the strand is cooled to a temperature above 700° C. and divided into thin slabs. The thin slabs then pass through an equalization furnace standing in line where they are reheated to a temperature ≦1170° C. and continuously rolled in a multi-stand hot rolling mill to give hot strip having a thickness of ≦3.0 mm. The first shaping pass is performed at a temperature in the rolling stock up to 1150° C. The reduction in thickness is at least 20%. The hot strip is cold rolled in one or more stages with recrystallizing intermediate annealing to a final thickness in the range of 0.15-0.50 mm. The cold strip is then annealed with recrystallization and decarburization, furnished with a predominantly MgO-containing annealing separator and given a final annealing for imprinting a Goss texture.
    Type: Grant
    Filed: June 6, 2000
    Date of Patent: February 25, 2003
    Assignee: Thyssen Krupp Stahl AG
    Inventors: Hans Pircher, Rudolf Kawalla, Manfred Espenhahn, Andreas Böttcher, Klaus Günther, Hans Huneus, Carl-Dieter Wuppermann
  • Patent number: 6503339
    Abstract: The invention relates to a method to produce non-grain-oriented magnetic steel sheet made of thin-slab or slab casting with low specific total loss and high polarisation and favourable mechanical properties. It is a characteristic of the invention that the steel slabs are hot rolled either directly from the casting heat or after a reheating to T≧900 ° C. and two or more metal forming passes are performed in the two-phase region austenite/ferrite in the course of finishing rolling.
    Type: Grant
    Filed: November 7, 2000
    Date of Patent: January 7, 2003
    Assignee: Thyssen Krupp Stahl AG
    Inventors: Hans Pircher, Rudolf Kawalla, Manfred Espenhahn, Brigitte Hammer, Klaus Peters, Jürgen Schneider, Carl-Dieter Wuppermann
  • Patent number: 6284069
    Abstract: The invention relates to a process for producing strips of homogenous structures and characteristics made of non-alloyed and low-alloyed steel by continuous hot rolling in several roll passes in the austenitic region and subsequently in the ferritic region, as well as coiling. The invention is characterised in that continuous-cast strip and/or strip rough rolled in the austenitic region, starting with a temperature T≧Ar3+30° C., with a total degree of deformation of eh≧30% is rolled in two or several roll passes in the austenitic region and in that the rolling stock is intensively cooled after every roll pass until the ferritic transformation has been completed, after which the rolling stock is end rolled to final thickness in the ferritic range in several passes with a total degree of deformation eh≧60%.
    Type: Grant
    Filed: December 28, 1999
    Date of Patent: September 4, 2001
    Assignee: Thyssen Krupp Stahl AG
    Inventors: Hans Pircher, Manfred Espenhahn, Rudolf Kawalla, Waldemar Wolpert
  • Patent number: 6284063
    Abstract: The invention concerns hot-rolled steel strip no more than 5 mm thick, optionally less than 2 mm thick, made of high-tensile steel, that contains 0.08%-0.25% carbon, 1.20% to 2.0% manganese, and 0.02% to 0.05% aluminum, and optionally up to 1.0% chromium, up to 0.1% copper, up to 0.5% molybdenum, up to 0.1% nickel, up to 0.009% nitrogen, up to 0.0025% B, and optionally a stoichiometric amount of titanium in relation to nitrogen. The steel strip has a greater than 95% martensitic structure, and a tensile strength of 800 to 1400 N/mm2.
    Type: Grant
    Filed: February 25, 1999
    Date of Patent: September 4, 2001
    Assignee: Thyssen Stahl AG
    Inventors: Manfred Espenhahn, Thomas Heller, Jürgen Esdohr
  • Patent number: 6153019
    Abstract: A process for producing a grain-oriented magnetic steel sheet in which a slab, made from a steel containing (in mass %) more than 0.005 to 0.10% C, 2.5 to 4.5% Si, 0.03 to 0.15% Mn, more than 0.01 to 0.05% S, 0.01 to 0.035% Al, 0.0045 to 0.012% N, 0.02 to 0.3% Cu, the remainder being Fe, including unavoidable impurities, is heated through and hot rolled to a final thickness between 1.5 and 7.0 mm. The hot strip is annealed and immediately cooled and cold rolled in one or several cold-rolling steps to the final thickness of the cold strip. The cold strip is subjected to a recrystallizing annealing process in a humid atmosphere containing hydrogen and nitrogen, with synchronous decarburization. A non-stick layer, essentially containing MgO, is applied to the surface of the decarburized cold strip which is then subjected to final annealing. The cold strip is then rolled into coils.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: November 28, 2000
    Assignee: Thyssen Stahl AG
    Inventors: Manfred Espenhahn, Andreas Bottcher, Klaus Gunther
  • Patent number: 5759294
    Abstract: A process for the production of grain oriented magnetic steel sheets having improved remagnetization losses consisting essentially of (in % by weight) more than 0.005% to 0.10% C, 2.5 to 6.5% Si, 0.03 to 0.15% Mn, 0.010 to 0.050% S, 0.010 to 0.035% Al, 0.0045 to 0.0120% N, and 0.020 to 0.300% Cu, and up to 0.15% Sn, the balance being iron and inevitable impurities. The process includes continuous casting or strip casting slabs with the above composition.
    Type: Grant
    Filed: October 23, 1996
    Date of Patent: June 2, 1998
    Assignee: Thyssen Stahl AG
    Inventors: Fritz Bolling, Andreas Bottcher, Manfred Espenhahn, Christof Holzapfel
  • Patent number: 5711825
    Abstract: A process for the production of grain oriented magnetic steel sheets comprises through-heating slabs containing more than 0.005% C, 2.5 to 6.5% Si, 0.03 to 0.15% Mn, 0.010 to 0.050% S, 0.010 to 0.035% Al, 0.0045 to 0.0120% N, and 0.020 to 0.300% Cu, the balance being iron and residual impurities, to a temperature which is lower than the solubility temperature T.sub.1 of magnesium sulfide and higher than the solubility temperature T.sub.2 of copper sulfide, T.sub.1 and T.sub.2 being dependent on the silicon content. The through-heated slabs are then hot roughed, followed by hot finish rolling at an initial temperature of at least 960.degree. C. and a final rolling temperature of 880.degree. C. to 1,000.degree. C., to produce a hot rolled strip having a thickness in the range of 1.5 to 7 mm. During this last step, at least 60% of the total nitrogen content precipitates in the form of coarse AlN particles. Thereafter, the hot rolled strips are annealed at temperature of 880.degree. C. to 1,150.degree. C.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: January 27, 1998
    Assignee: Thyssen Stahl AG
    Inventors: Fritz Bolling, Andres Bottcher, Manfred Espenhahn, Christof Holzapfel
  • Patent number: 4347115
    Abstract: An apparatus is disclosed for the electroplating of metal strips, and more particularly for the zinc-coating of steel strip, which comprises a tank filled with electrolyte liquid and immersed therein, at least one anode which is disposed above a strip to be electrolytically coated and at least one anode disposed below said strip, both of said anodes being parallel to said strip. The anode disposed above the strip is electrolytically consumable and made of an electrolytically depositable metal for deposition on said strip and the anode disposed below the strip consists essentially of a material that is insoluble in the electrolyte and not electrolytically consumable. Each anode is connected to a source of current, the anode disposed below said strip being provided with means for disconnecting it from said source of current.
    Type: Grant
    Filed: May 1, 1981
    Date of Patent: August 31, 1982
    Assignee: Thyssen Aktiengesellschaft vorm. August Thyssen-Hutte
    Inventors: Manfred Espenhahn, Manfred Folwaczny