Patents Assigned to Choeller-Bleckmann Oilfield Technology GmbH & Co. KG
  • Patent number: 6764647
    Abstract: A material which is suitable for equipment in oilfield technology and a process for making the material. The material consist essentially of C, Si, Mn, Cr, Mo, Ni, Cu, N in certain weight percentages, with the balance iron and contaminants due to manufacture. The material is hot formed in a condition free of nitride precipitates and without precipitated associated phases. After a cooling, it is cold formed in a condition free of ferrites. The material has certain values of relative magnetic permeability, yield strength (Rp0.2), notched impact strength, fatigue strength under reversed stresses, and fracture appearance transition temperature.
    Type: Grant
    Filed: August 12, 2002
    Date of Patent: July 20, 2004
    Assignees: Choeller-Bleckmann Oilfield Technology GmbH & Co. KG, Kohler Edelstahl GmbH
    Inventors: Herbert Aigner, Josef Bernauer, Gabriele Saller