Patents by Inventor Ludwig Ettenreich

Ludwig Ettenreich 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).

  • Continuous heat treating process for low carbon structural steels in bar form
    Patent number: 3933534
    Abstract: An improvement in a process for preparing a structural steel having a maximum carbon content of 0.26 weight percent, the balance comprising iron, wherein the steel is continuously heated with the use of rapid heating, followed by quenching, the improvement comprising heating the steel only in its shell to a temperature between A.sub.cl and 1,300.degree.C such that the core heats up at an average rate of at least 100.degree.C/sec. up to a temperature between incipient pearlite transformation (A.sub.cl) and 900.degree.C, and thereafter, but prior to the attainment of equilibrium with respect to the carbon content, quenching said steel.
    Type: Grant
    Filed: May 11, 1972
    Date of Patent: January 20, 1976
    Assignee: Bau-Stahlgewebe GmbH
    Inventors: Ludwig Ettenreich, Otto Reimann, Klaus Greulich