Patents by Inventor Hans Rydstad

Hans Rydstad 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: 4909859
    Abstract: A process for increasing the oxidation resistance and corrosion resistance of a component made of a dispersion strengthened superalloy by means of a surface treatment, the object of which in every case is to produce or retain a fine-grained surface zone (5) while the core zone (4) of the component in all circumstances is forced to form coarse grains during the final recrystallization annealing in the temperature range between the recrystallization temperature and the solidus temperature. A fine-grained surface zone (5) is produced by cold-working the surface zone (3, 5) by shot-peening, surface milling or pressing or by heating the surface zone (7) to a temperature about to C. below the recrystallization temperature by means of a laser (9) or an arc (10) while the core zone is kept at less than C., or by application of a 10 to 50 .mu.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: March 20, 1990
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Mohamed Nazmy, Hans Rydstad
  • Patent number: 4750946
    Abstract: Components (5) in a superalloy, in particular a dispersion hardened nickel based alloy, are connected together by pressure bonding in the solid condition with the greatest possible limitation of the overall deformation of the complete components (5) by lateral restraint (7), the actual bonding zone (6) having short-term intensive dynamic plastic flow imposed on it and, taking account of the deformation temperature, the local deformation rate .epsilon..sub.l and the local deformation .epsilon..sub.l referred to the bonding zone (6) are matched together in such a way that the driving force during the subsequent heat treatment of the complete workpiece above the recrystallization temperature is sufficient to force the formation of coarse grain under all conditions. It can then be assumed that, in general, the expression ##EQU1## h.sub.o =height of the bonding zone (6) before connection, h.sub.f =height of the bonding zone (6) after connection,D.sub.
    Type: Grant
    Filed: February 12, 1986
    Date of Patent: June 14, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Bernd Jahnke, Gernot Gessinger, Hans Rydstad, Robert Singer
  • Patent number: 4722469
    Abstract: Components made of a dispersion-hardened superalloy are connected together by pressure bonding, the individual parts previously processed at their bonding surfaces only by milling, without fine machining such as grinding, electro-polishing, etc., being subjected before bonding to a heat treatment in the temperature range of between C. and C. below the recrystallization temperature for the purpose of reducing the driving force. During the subsequent coarse-grain heat treatment of the bonded workpiece, no sort of fine crystalline banding occurs in the bonding zone and the strength of the workpiece corresponds to that of the material before bonding.
    Type: Grant
    Filed: May 29, 1986
    Date of Patent: February 2, 1988
    Assignee: BBC Brown, Boveri & Company, Limited
    Inventors: Hans Rydstad, Robert Singer
  • Patent number: 4612062
    Abstract: A fine-grained workpiece having improved mechanical properties is produced from a nickel-based superalloy by two-part forging, a blank being converted, in a first isothermal hot-forming step (curve b) above the solution-annealing temperature for the .gamma.'-phase (line a), into an intermediate form and the latter then being finally forged to give the end form in a second isothermal hot-forming step (curve c) just below the solution-annealing temperature for the .gamma.'-phase. For the first step, a degree of deformation .epsilon. of of at least 0.7 at a mean deformation rate .epsilon. of about 10.times.10.sup.-3 s.sup.-1 is required here. The second step is carried out at deformation rates .epsilon. which are one to two powers of 10 lower than those of the first step.
    Type: Grant
    Filed: September 28, 1984
    Date of Patent: September 16, 1986
    Assignee: BBC Brown, Boveri & Company, Ltd.
    Inventors: Mohamed Y. Nazmy, Hans Rydstad, Gunther Schroder, Robert Singer
  • Patent number: 4601186
    Abstract: A process and apparatus for achieving narrow workpiece tolerances in isothermal drop-forging, the relative movement of the two die halves (1, 2) in an xy plane perpendicular to the pressing direction z being measured and monitored by means of an optical measuring device (10, 11, 12, 14) or mechanical measuring device (14, 15, 16) and being corrected by means of a mechanical adjusting device (6, 17, 21, 23, 24, 25, 26) for one die half (2). A first workpiece is forged, and the divergence from the nominal value is measured, with the die halves (1, 2) closed, the die halves (1, 2) are opened, the first workpiece is removed, the position of one die half (2) is corrected, and a new workpiece is introduced and forged completely, without the workpiece having to be cooled and remeasured and without the die having to be cooled and reheated.
    Type: Grant
    Filed: February 14, 1985
    Date of Patent: July 22, 1986
    Assignee: BBC Brown, Boveri & Co., Ltd.
    Inventors: Roland Kunzli, Hans Rydstad
  • Patent number: 4399618
    Abstract: A method and a device, FIG. 1, for sealing an opening (15, 8, 10) between two zones in a fluidized bed and/or between the bed and its surrounding (22). In the bed particles (2) are intended to be maintained suspended by means of a carrier gas, which is introduced in the bottom (3) of the bed below the level of aid opening (15, 8, 10). Through said opening (15, 8, 10) primarily workpieces (66) intended to be treated in the bed are intended to pass, which opening (15, 8, 10) is, for example, a horizontal gap in a vertical partition wall (11, 9) between the zones (12, 13, 14) or between the bed and its surrounding (22). The method according to the invention is characterized in that a heap (19, 27) or several heaps (19, 27) of particles (2), by utilizing the movements of the particles (2) and carrier gas in the bed, are caused to be built up at said opening (15, 8, 10) to such a height that the opening (15, 8, 10) is covered or substantially covered by the heap/heaps (19, 27) of particles (2).
    Type: Grant
    Filed: September 28, 1981
    Date of Patent: August 23, 1983
    Inventor: Hans Rydstad