Westinghouse Electric Corporation

Siemens Westinghouse Power Corporation

Westinghouse Electric Company LLC

Dennis R Amos

Robert E Clark

Jianqiang Chen

Sallie Ann Bachman

Robert L Novak

Kent Wixon Beedon

Roger W Heinig

Stephen R Reid

Delbert Eugene Conklin

David Joseph Knapp

Timothy Lee Driver

Timothy L Driver

This invention relates to an improved method for repairing damaged or worn surfaces of turbine components or upgrading older designs to new, improved designs. This improved method applies to both high pressure and low pressure turbine components applications. This method includes depositing a plurality of individual spaced apart weld volumes onto a prepared surface of a turbine rotor. These individual spaced apart weld volumes form individual fingers without the need to machine the individual fingers from a single rectangular weld volume. Multiple weld volumes are formed concurrently with a space maintain between each weld volume using multiple torches without the problems normally associated with closely spaced welding arcs. Each individual spaced apart weld volume is formed by a plurality of layers of weld metal, with each layer being formed from a single oscillating weld bead to form a predetermined width. The filler wire may be heated by applying a current through the filler wire before it is fed into the weld pool. Welding parameters are also changed to increase the amount of weld deposition without adversely affecting the mechanical weld properties. The invention provides for reduced cycle time for repair work by using multiple torches simultaneously without causing arc instability. The invention also reduces cycle time, by eliminating the need of machining individual fingers on control stages from a single weld volume, by changing the weld buildup of multiple projections, slightly larger than the fingers which hold the blades.

Turbine rotor modernization and repair method

The invention provides a blade-rotating device for rotating a plurality of radially-oriented blades having a blade base with two grooved base sides. The device has a portion, such as a disc or a rotor disc of a turbine, for rotating the blades with the portion having an outer cylindrical surface. The device also has a plurality of steel steeples each having a steeple base and two opposite grooved steeple sides extending therefrom. Each of the opposite steeple sides complements at least one of the grooved sides of at least one of the blade bases. The steeple bases are linear friction welded to the outer cylindrical surface in an approximately longitudinal direction such that the blade bases are engagable with the steel steeples.

Linear priction welding of steeples and device thereof

A welding process of repairing a ferrous NiMoV low alloy steel turbine component. A first and a second layer of weld material are welded to the turbine component at electrical current levels chosen so as to prevent a substantial decrease and a substantial increase in the hardness of the component. This method involves selecting these electrical current levels. Additionally, this invention relates to selecting appropriate electrical current levels that minimizes the difference between a maximum and a minimum level of hardness while welding a first and a second layer of weld material. This invention also includes a method for preventing a substantial decrease in the hardness of the component as a result of the welding process.

Optimized welding technique for NiMoV rotors for high temperature

A method of removing blades from the rotor of a turbo machine, such as a steam or gas turbine, in which material deposits formed between the surfaces of the blade root and its retaining groove have effectively bonded the blade root to the rotor groove. The blade root and groove are submersed in a liquid medium enclosed in a tank. Transducers installed on the tank radiate ultrasonic pressure waves into the liquid medium that breakup the material deposits through cavitation, thereby loosing the bond between the blade root and the groove. The blade is then removed from the tank and the blade slid out of the groove.

Method of removing blades from a turbo machine

A formed disc for use in a low pressure rotor has a rim made of a high alloy metal of between approximately 9% and 17% chromium. The rim can be annular in shape and slide onto the perimeter of an unformed disc for the two components to be fused together, thus fabricating a formed disc. Additionally, the rim can be split into a number of components and fused together on the perimeter of a rotor disc to form a complete rim. Further, an entire disc can be made out of the high alloy metal.

Stress corrosion resistant rims and discs for steam turbine rotors

A low pressure steam turbine and generator low alloy steel disc rotors with extended useful life properties. A ring member of the disc rotor has disposed on it multiple weld layers of ferrous material, forming a weld region. The ring member is made of a low alloy ferrous metal alloy having less than about six weight percent alloying ingredients including chromium. The chromium content of the weld region increases overall from a portion of the weld region adjacent to the ring member to a portion of the weld region farthest from the ring member. This general increase is accomplished using weld metal of a single chromium concentration of between 9% and 17% chromium and varying the welding parameters.

High chromium content welding material to improve resistance of

A process of depositing layers of weld metal onto a ferrous NiMoV low alloy steel turbine component. During a deposition of a first layer of weld metal, low levels of amperage are used to prevent a dramatic increase in a level of hardness of a heat affected zone produced during the deposition of the first layer of weld metal. During a deposition of a second layer of weld metal, higher levels of amperage are used to temper the heat affected zone but not high enough to overtemper the HAZ.

A filler wire weld composition is set forth which provides high yield strength characteristics comparable to a base substrate made from a high performance Ni--Cr steel alloy. The filler wire weld composition is useful for repair welding substrate alloys used commercially in contexts such as turbine components such as rotors and discs.

Filler wire composition and method of welding turbine component with

This invention provides alloys having optimum high and low temperature mechanical properties for use of both the high and low pressure ends of turbine rotors in a single row power generation turbine with a service temperature profile from about 75.degree.-1200.degree. F. (24.degree.-649.degree. C.). The alloys include about 8.00-9.5 wt. % Cr and about 0.85-1.05 wt. % Mo and are heat treated at 1225.degree.-1350.degree. F. (663.degree.-732.degree. C.) for at least about one hour. The alloys and the components manufactured from these alloys preferably include a room temperature 0.2% yield strength of about 80-110 ksi (551-758 MPa).

Single alloy system for turbine components exposed substantially

A steam turbine blade is provided having a trailing edge portion formed from an erosion resistant material deposited on the blade airfoil by a friction surfacing method. According to the method, a rotating consumable rod of erosion resistant material is placed in contact under axial load against a bonding surface formed on the airfoil, thereby causing a portion of the rod adjacent the bonding surface to be plasticized. The rod then traverses the surface linearly leaving in its wake a layer of erosion resistant material bonded to the airfoil by a high quality metallurgical bond. The layer is then ground to form the smooth contour desired for the trailing edge.

Method of forming a trailing edge on a steam turbine blade and the blade

A method for repairing a rotor includes severing the rotor into two or more rotor segments. After removing a portion of material including the crack from the rotor, weld metal is deposited onto the rotor until the removed portion is replaced with weld metal. A built-up portion is welded onto a surface positioned adjacent a bore of each of the rotor segments. One of the built-up portions is machined into a female spigot and the other build-up portion is machined into a male spigot for engagement of the rotor segments. The female and the male spigots are engaged for alignment of the rotor segments. The rotor segments are welded together with weld metal, which is deposited in a welding groove formed between the rotor segments and the spigots. After the rotor segments are joined together, the male spigot, the female spigot, and a portion of the weld metal positioned near the root fusion area are removed to restore the bore of the rotor to its original diameter.

Method for repairing a rotor

A turbine rotor is formed from two rotor segments that are composed of different low alloy steels, one a high temperature alloy and the other a low temperature alloy. The rotor segments have cavities in confronting faces that form an annular flange at the outer surface, with the segments welded together across the flange. A clad layer is first welded on one of the flanges and a filler material welds the clad layer to the other flange to form a composite turbine rotor.

Method of making a high temperature - low temperature rotor for turbines

A more creep resistant turbine rotor and novel methods for repairing worn surfaces of Cr-Mo-V steam turbine components are disclosed. These methods include specified alloy compositions and welding procedures that minimize weld stresses and cracking. These alloys exhibit improved creep and fatigue properties and are preferably deposited using a gas tungsten arc welding procedure. Bead sequencing, cooling side plates and the use of run-off tabs are also disclosed for minimizing welding defects in turbine rotors and discs.

More creep resistant turbine rotor, and procedures for repair welding of

System for repairing worn surfaces of steam turbine components and especially high pressure turbine rotors, are disclosed. These systems include depositing a first layer of weld metal on a worn surface of the component, whereby a heat-affected zone is created. A second layer of weld metal is then deposited over the first layer using a greater amount of heat to temper at least a portion of the heat-affected zone produced by the first layer. The preferred embodiments include the use of gas tungsten arc welding for providing fine-grain size and more creep resistance, especially in the weld and heat-affected zone. The resulting build-up can be machined, for example into a blade fastening to produce a component having properties equal to or better than the base-metal alloy. The invention also provides a longer lasting turbine system, including rotors which have serrated steeples that are more resistant to failure.

Turbine system having more failure resistant rotors and repair welding

Novel methods for repairing worn surfaces of turbine rotors, are disclosed. These methods include depositing a first layer of weld metal on a worn surface of the component, whereby a heat-affected zone is created. A second layer of weld metal is then deposited over the first layer using a greater amount of heat to temper at least a portion of the heat-affected zone produced by the first layer. The preferred embodiments include the use of gas tungsten arc welding for producing fine-grain size and more creep resistance, especially in the weld and heat-affected zone. The resulting build-up can be machined, for example into a blade fastening to produce a component having properties equal to or better than the base-metal alloy. The invention also provides a longer lasting turbine system, including rotors which have serrated steeples that are more resistant to failure.

Growing community of inventors

Rock Hill, SC, United States of America

Dennis R Amos