Abstract: Material in fluid form is applied to a region where a joint is to be formed between an airfoil and an adjacent structure by simultaneously directing streams of the material into the joint region on the suction side of the airfoil and into the joint region on the pressure side of the airfoil. The material may be so applied using a syringe type applicator that has a nozzle with a first arm and a second arm. The first arm is in flow communication with a source of the material and the suction side surface of the airfoil. The second arm is flow communication with a source of the material and the pressure side surface of the airfoil. Applying the material simultaneously to the joint regions on the suction side and the pressure side of the airfoil reduces the amount of time and effort needed to apply such material.

Abstract: A steam turbine different material welded rotor, constructed by rotors of different materials being jointed together by welding has the strength of a jointed portion increased and inspection of the jointed portion facilitated. A bearing portion rotor 1 and high temperature portion rotor 2 are jointed at weld portion A, the high temperature portion rotor 2 and low temperature portion rotor 3 at weld portion B and the low temperature portion rotor 3 and bearing portion rotor 4 at weld portion C. Cavity portions 5, 6 are formed in the weld portions B, C, respectively. Inspection holes 7, 8 are also provided in the weld portions B, C. The high temperature portion rotor 2 is made of high heat resistant 12Cr steel and other rotors are made of low alloy steel, wherein the rotor 1 is of 2.multidot.1/4 CrMoV steel and the rotors 3, 4 are of 3.multidot.1/2 NiCrMoV steel.

Abstract: A process for joining a base for an airfoil to a disk for an integrally bladed rotor stage in a gas turbine engine includes providing a disk having a radially outer rim with a slot defined therein by a recessed surface, and further includes providing a base having a longitudinally extending root portion facing opposite a longitudinally extending support portion for supporting the airfoil. The root portion has a root surface and the support portion has an outer surface. The process further includes bringing the root surface of the root portion into contact with the recessed surface bounding the slot, applying pressure and relative movement between the base and the rim to achieve during welding, substantial contiguity between the root surface and the recessed surface over the area of the recessed surface, resulting in a substantially continuous linear friction weld between the base and the rim.

Abstract: An improvement in an electrical air pump having a housing with a pump mechanism at one end and an electric motor at the other end. The pump mechanism has at least one lightweight pump impeller made of plastic whose hub is press-fit on a shaft of the electric motor. The hub is provided with a plurality of grooves distributed around a bore in the hub which receives the motor shaft. The grooves form spaces between an inner surface of the hub and an outer surface of the shaft and the spaces are filled with an adhesive to bond the hub to the shaft. The grooves extend longitudinally or spirally along the entire length of the hub. The grooves are relatively shallow and have a depth of approximately 0.05 mm.

Abstract: 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.

Abstract: A turbine rotor consisting of a wheel made of a TiAl alloy of good heat resistance and a rotor shaft made of a steel with good bonding strength is disclosed. As the shaft material a structural steel or a martensitic heat resistant steel is used. A TiAl turbine wheel made by precision casting is butted to the shaft with insertion of a brazing filler in the butted interfaces and stress of 0.01 kgf/mm.sup.2 or higher but lower than yield stress of the shaft is applied on the butted interfaces under heating by high frequency induction heating in atmosphere of an inert gas or a reducing gas to a temperature higher than the liquidus temperature of the brazing metal but not exceeding 100.degree. C. above the liquidus temperature.

Abstract: An improved coal mill exhauster fan having an elongated, conical hub welded to the blades and engaging the rear shroud plate to eliminate air gaps along the rear of the fan assembly and to assist in axial to radial directional changes of the coal flow; two-piece blade assemblies having a sub-blade welded directly to the hub and shroud plates, and a protective liner removably secured to the sub-blades only, for example by bolts; a plurality of swept-back stiffener ribs welded to the rear undersides of the sub-blades, hub and shroud to increase rigidity, and with angled deflector faces to reduce erosion; and an improved hub cap or spinner seal which extends further toward the housing inlet than traditional Cooley caps and which forms a smooth, non-turbulent extension of the hub relative to the incoming coal flow.

Abstract: In a turbo engine's welded rotor includes a number of disks, the radially or quasi-radially extending welding seams are intermediately interrupted by annular cavities through which a cooling medium flows, and these cavities are surrounded by a circumferentially extending insert ring. This insures the flow of the cooling medium through the entire rotor without reducing the strength of the welding bond.

Abstract: A turbomachine rotor stage having a thin annular body comprising a metal alloy part reinforced by at least one fibrous ring which has a radial height h of at least 1.5 times its axial width l and which is embedded in the metal alloy part so that it projects radially outwardly from the inner wall thereof in order to stiffen the body and reduce the quantity of fibre material to be used.

Abstract: An electroformed sheath is disclosed for protecting composite components of a part, such as a fan blade of a modern gas turbine engine. The electroformed sheath includes a sheath body having a leading edge; a pressure side and an opposed suction side of the body that meet at the leading edge and extend away from the leading edge to define a sheath cavity therebetween; a head section of the body between the leading edge and the sheath cavity; and an electrically conductive mandrel insert positioned between the pressure and suction sides of the body. In manufacture of the electroformed sheath, the mandrel insert is secured in an appropriate mandrel having an exterior surface approximating the blade's airfoil configuration. The leading edge, head section and pressure and suction sides are electroplated around the mandrel insert so that the insert remains in the sheath body after removal of the mandrel.

Abstract: A blade for a rotor, especially a turborotor, is made of two hollow blade foot sections having matching seam surfaces to form a hollow blade with a thickened foot that is butt-welded with its blade foot sole (7) to an integral welding stub of a rotor hub or disk. The two hollow blade foot sections are soldered to each other along a radially outer seam section (5) between the seam surfaces and welded to each other along a radially inner seam section (6) between the seam surface. The radially inner seam section extends from said blade foot sole. The welded seam normally ends in the thickened blade foot section (6) and is thus shorter than the soldered seam section (5).

Abstract: A surface defect in a gamma titanium aluminide article is repaired by weld repairing the defect and thereafter sealing the surface-connected cracks in the weldment. The surface-connected cracks are repaired by applying to the region of the weldment a powder of a brazing filler metal that is compatible with the gamma titanium aluminide alloy and with the weldment, and thereafter heating the article to a brazing temperature above the liquidus of the brazing filler metal. The article is preferably hot isostatically pressed after the repair is completed to close internal defects that cannot otherwise be closed due to the surface connected cracks.

Abstract: A sealing apparatus and method for delivering a sealing material to gaps between gas turbine blade roots and the corresponding grooves of a rotor disc are disclosed. The sealing apparatus comprises a tank for housing a pressurized sealing material, a delivery tube for delivering the sealing material from the tank to the rotor disc, a control valve for controlling the flow of the sealing material, a sealing fixture for distributing the sealing material to the gaps between the blade roots and the corresponding grooves, an O-ring seal for effecting a tight seal between the sealing fixture and the rotor disc, and jack screws for maintaining the sealing fixture securely in place.

Abstract: A turbine rotor comprising a radially-inward portion of a steel alloy and a radially-outward rim portion circumscribing the radially-inward portion, the rim portion being formed by a weldment that includes a nickel-base superalloy region joining the rim portion to the inward portion of the turbine rotor, the nickel-base superalloy having a room temperature ultimate tensile strength of at least about 690 MPa.

Abstract: A safety shroud of a nuclear reactor coolant pump. Capscrew heads, if broken, are prevented from separating from a nuclear reactor coolant pump having a drive shaft, an impeller secured to the drive shaft, a suction deflector secured to the impeller, and capscrews with outer heads securing the impeller and suction deflector to the drive shaft, by securing a safety shroud over the capscrew heads. The safety shroud may be secured by welding the safety shroud to the impeller or suction deflector, or by bolting the safety shroud to the distal end of the drive shaft.

Abstract: A turbine wheel for a torque converter for an automatic transmission is formed of fiber-reinforced plastic resin molded about a powder metal hub having a disc formed with corrugations extending radially from a central axis, and slots extending through the thickness of the disc at angularly spaced intervals. The plastic resin of the turbine wheel fills the spaces between the tabs, extends through the slots formed through the disc, and forms a bond to the surfaces of the disc on which it is molded.

Abstract: A lightweight high temperature rotor blade attachment structure for use in a gas turbine engine. The lightweight high temperature rotor blade attachment lug being cast of a single crystal alloy and the lug is then bonded to a conventional nickel based wheel. A circular arc firtree is utilized to connect the insertable turbine blade between a pair of circumferentially spaced lugs that have been bonded to the turbine disk. In an alternate form of the present invention the attachment lug includes an internal cooling passage for receiving cooling fluid from a compressor. More particularly, the present invention discloses a single crystal attachment lug that is bonded to a powdered metal nickel alloy rotor disk and includes internal cooling passages, and in one form is designed for use with turbine blades that do not have a platform.

Abstract: This compressor is provided with a compressor impeller (1) which has a hub (2) of plastic fitted with moving blades (5), with a shaft which is connected to the hub (2) and extends along an axis (4), and with a housing which surrounds the compressor impeller (1).It is intended to provide a compressor which has a compressor impeller produced from a plastic and is nevertheless suitable for comparatively high operating temperatures. This is achieved by the hub (2) of the compressor impeller (1) being produced from a thermoplastic reinforced with continuous fibers, and by the moving blades (5, 20) being prefabricated separately from a thermoplastic reinforced with continuous fibers and connected with a form fit to the hub (2).

Abstract: A rotor disc which is suitable for carrying the fan blades of a ducted fan gas turbine engine is constituted by two sub-discs which are maintained in axially spaced apart relationship by a plurality of spacer members. The spacer members are generally axially extending and at least partially define the operational air flow path over the disc.

Abstract: A method of assembly of impeller (12) and turbine (14) shells (116) for torque converters (10). Vanes (116) are capacitance discharge welded with a high energy pulse into the shells (112).

Abstract: To manufacture a turbine wheel having blades made of a ceramic or composite material and inserted into a metal hub, firstly blades (16) are manufactured that are right cylindrical, each blade having a base (18) through which a hole is formed; a cylindrical ring (20) is formed, the ring being provided with orifices through which the bases (18) of the respective blades (16) are inserted; the blade bases (18) are successively threaded onto an open annular rigid metal wire (30); the resulting assembly (16, 20, 30) is disposed inside a sealed housing (161); hot isostatic compaction is performed so as to compact a metal alloy in powder form (41) inside the sealed housing (161) so as to make the hub of the turbine wheel (100) while embedding the blade bases (18) and the metal wire (30) by using the powder metallurgy technique; and the outside portion of the sealed housing (161) delimiting the hub of the turbine wheel (101) is machined. Application, in particular, to the field of aeronautical or space engineering.

Abstract: The present invention relates to a monobloc rotor having a disk and hollow blades which are secured to the disk. The disk includes a protuberance and a projection on a periphery of the disk such that the projection forms a block having a shape which approximately corresponds to a shape of an inside of a radially internal extremity of the blade. The present invention further relates to a monobloc rotor in which a block is welded to the protuberance with the block forming a projection having a shape which approximately corresponds to a shape of an inside of a radially internal extremity of the blade.

Abstract: A turbine compressor or turbine bladed disc assembly wherein the blades 6 include root portions 8 provided with opposed converging surfaces 9,10 and the disc 14 includes slots 11 provided with opposed diverging surfaces 12,13. In assembly the root portion 8 of a blade 6 is engaged in a slot 11 with abutting converging and diverging surfaces and the blade 6 is oscillated relative to the disc whilst pressure is applied radially to urge the root into close contact with the slot until melting temperature is reached whereupon the oscillatory motion is arrested and the pressure maintained as the converging and diverging surfaces coalesce. A hole 16 may be drilled through the assembled blade and disc assembly in order that communication may be made with cooling air passages in the blade.

Abstract: A ventilator fan device including a male wheel, a female wheel and arcuate blades. The male wheel forms an end plate having an axis of rotation. The end plate includes a hub for mounting the wheel to a shaft. The female wheel forms a ring inlet for axial inlet of air. A plurality of longitudinal arcuate blades extend between and conform to the plate annular portion and the ring inlet. The blades are positioned for radial discharge of air upon rotation of about the axis. Substantially uniform robotic welds permanently affixing the blades to the end plate and the ring inlet.

Abstract: A turbine blade comprises an airfoil/shank having a shank region and an airfoil region extending upwardly therefrom and two dovetail/platforms bonded thereto. The first dovetail/platform has a first dovetail region bonded to a first side of the shank region of the airfoil/shank, with a first platform region extending outwardly from the first dovetail region. The second dovetail/platform has a second dovetail region bonded to a second side of the shank region of the airfoil/shank and a second platform region extending outwardly from the second dovetail region in a direction generally opposite to that of the first platform region.

Abstract: A rotor assembly for supporting rotor blades includes a plurality of axially adjoining discrete disks each having a rim, web, and hub. The rims include axial dovetail grooves for collectively supporting a respective blade dovetail therein. Each of the disks includes at least one axially extending annular arm joined integrally with the disk and fixedly joined to an adjacent one of the arms. The disks are fixedly joined together solely by the blade dovetails in the rim dovetail grooves and by the arms so that upon a crack failure of one of the disks, centrifugal load from the failed disk is transferred to an adjacent disk.

Abstract: A securing structure and method of a blade for torque converter for use mainly in industrial construction vehicles to provide its rigid and easy-to-manufacture construction. The structure includes plural circular blades which are secured to a concave surface of a shell with some space in the circumferential direction, a core ring which extends along the circumferential direction of the shell and is secured to concave peripheries of the blades. A tab fitting in slot of the shell is formed integrally on the convex periphery of the blade. A tab fitting in a slot of the core ring is formed integrally on the concave periphery of the blade. Ribs extending in the circumferential direction of the shell are only formed on both ends of the convex periphery and concave periphery of the blade. The convex periphery and the concave periphery are brazed to the shell and the core ring respectively.

Abstract: A method is taught for the isostatic forging of integrally bladed rotors, in which deformable hollow single crystal blades are protected from deformation during diffusion bonding to the disk by encapsulation in a ceramic protective shell. The ceramic shell serves to occupy the areas between the blades and the surrounding forging die set, so that during application of high temperatures and pressures, damage to the blades is prevented without the use of complex segmented die assemblies.

Abstract: An impeller for a centrifugal pump has a hub which is designed to be affixed to the pump shaft. The hub carries a first cover plate which is located at the pressure side of the impeller and supports a series of vanes defining flow channels. The first cover plate is secured to the bases of the vanes and a second cover plate situated at the suction side of the impeller abuts the tops of the vanes and overlies the flow channels. A suction port constituting an individually manufactured component is disposed at the inlet of the impeller and has a section of constant diameter which faces away from the vanes as well as a section of variable diameter which confronts the vanes. The section of variable diameter is connected to the tops of the vanes by a weld seam. The second cover plate overlies that end portion of the suction port having the greatest diameter and is secured to the tops of the vanes in an area between the suction port and the impeller outlet.

Abstract: This invention provides stream turbine components, such as rotor disc, which include a ring member comprising a low alloy ferrous base metal having less than about 6 wt. % alloy ingredients and a ferrous graded layer disposed on the ring member which includes a plurality of layered weldments having an increasing weight percentage of a layering metal containing Cr. Disposed on the graded layer of this invention is a Cr-containing steeple alloy disposed on the graded layer for optimizing a life extending property of the steeple region of the turbine component.

Abstract: A pump impeller manufactured by press forming of steel plate and comprising a boss formed with a central bore for connecting the boss to a main shaft of the pump through key and key way engagement, and a main shroud fixed to the boss is disclosed. The impeller is characterized in that the boss is formed with a polygonal portion on the periphery of the boss and the main shroud is formed at central portion thereof with a polygonal recess fitting to the polygonal portion of the boss. A retainer plate is mounted on the boss at an end portion thereof opposite to an end portion from which the main shroud is fitted to the boss and is connected by welding to the main shroud. Thereby, since the power is transmitted from the boss to the main shroud through polygonal surfaces, no substantial stress concentration occurs at the power transmitting area.

Abstract: A fiber-structured [guide] rotor blade is connected to a metallic rotor in that a supporting core, around which fiber layers are wound, and which extends over the whole blade width, has radial webs in its central section. This results in a form-locking fastening which utilizes the characteristics of the fiber materials.

Abstract: A rotor assembly includes a shaft and a planar vane extending in a radial direction from the shaft and having a peripheral groove receiving a resilient sealing gasket. The vane includes a tongue portion which depends into a radial cavity in the shaft and is sealably cemented thereto. Radially extending ribs on the ends of the tongue are accurately fitted against the ends of the cavity which are aligned with the adjacent ends of the bottom walls of the peripheral groove.

Abstract: A dual alloy gas turbine rotor is heat treated by HIP bonding a cast superalloy blade ring to a consolidated, powdered-metal hub. After bonding, the assembly is solution treated and aged at certain specific temperatures so as to optimize the mechanical properties of the dual alloy assembly for use in a high performance gas turbine engine.

Abstract: A composite compressor wheel for turbochargers and the like comprises a cast shell having aerodynamically contoured centrifugal impeller blades and a hub section defining a generally conical recess into which a hub insert of noncast material resistant to stress failure is secured as by inertia welding. In use of the composite wheel, the hub insert substantially occupies high stress regions within the wheel to improve wheel fatigue life.

Abstract: In this method of lengthening the blade aerofoil (5) of turbo machines by building up with weld in the assembled condition of the blades, the position (4) to be welded at the end of the blade aerofoil (5) is encased by a metal mold (1,2). The mold (1,2) has a connection (3) where one pole of the welding circuit is connected. The end (4) of the blade aerofoil is lengthened or repaired by applying runs of weld. The mold (1,2) can be optionally supplemented with heating and/or cooling arrangements and also with a protective gas supply.

Abstract: A method and apparatus for reducing stress concentrations in a turbomachine rotor assembly are disclosed. A layer of superplastic metal is applied to a bearing surface formed on the turbine blade root. After assembly of the turbine blade to the rotor disk, the blade is pre-loaded to bring the superplastic metal layer into contact with adjoining bearing surfaces formed in the rotor disk groove. The superplastic metal material is capable of plastically deforming at least 500% thereby conforming to substantially all of the variations between the bearing surface formed on the blade root and the corresponding bearing surface formed on the rotor disk groove. By maximizing the contact area between the bearing surfaces, the stress concentrations are reduced.

Abstract: A turbine rotor with air cooled blades has a turbine disk and a continuous hoop circumferential turbine rim bonded thereto. The rim has a plurality of circumferential rings extending toward the disk and forming circumferential chambers therebetween.Near the outer edge of the turbine rim are transversely extending openings. The rim is wire cut from these openings from the outer periphery forming segmented blade platforms, allowing the thermal expansion of the platform to occur. Tubes within the openings convey cooling air to the circumferential chambers, from which it passes to the blade interiors and through cooling openings in the platforms.

Abstract: A welding beveling of a T-joint of a member welded to a rib on a lower plate, the rib varying in thickness along its length, comprises a beveling on an upper plate partially overlapping the rib at the thicker portion of the rib and having a clearance between the upper plate and the rib at the thinner portion, and a part of the beveling at the thicker rib portion being provided with a detecting hole for detecting the overlap.

Abstract: A control wheel intended for welding onto the high-pressure rotor of a steam turbine is manufactured from a ring of individual blades welded together. For this purpose, all of the individual blades are provided with shrouds and root platforms having welding grooves formed therein. After being welded together into a ring, closed on all sides, the control wheel is annealed, machined and finally heat-treated.

Abstract: A rotor-shaft assembly which includes a ceramic, solid hubbed turbine rotor having an integral stub shaft brazed within one end of a generally cylindrically shaped sleeve member. A metal shaft is either brazed or cold press fitted within the other end of the sleeve member in a torque transmitting relationship. The stub shaft is formed with an annular relief therearound in order to reduce the compressive forces acting on the stub shaft by the sleeve member.

Abstract: Two-part turbine-blade retainer structures are disclosed for axial retention of each of a plurality of turbine blades to a rotor wheel, wherein radial retention is via fir-tree engagement of individual blade roots to the wheel. In a preferred embodiment, a male or bolt element of the retainer has a shank which is characterized by a smoothly cylindrical portion adjacent at one end to one of the heads; this cylindrical portion terminates at a shoulder, beyond which the shank is reduced and externally threaded. A sleeve or nut element of the retainer has an elongate threaded bore and is characterized by an outer cylindrical surface which extends to the second head. The two elements are proportioned to be inserted through opposite ends of a passageway and to be screwed together into firm engagement at the shoulder (i.e., at a location intermediate the two heads), with the sleeve covering the threads of the male element and the heads preventing the turbine blade from axial motion with respect to the wheel.

Abstract: A circumferential array of aerofoil blades (11) comprising an aerofoil portion and a root portion is mounted on the periphery of a disc (14), sealed in place under vacuum and subsequently hot isostatically pressed to achieve diffusion bonding across the interface between the array (11) and the disc (14). Each of the root portion of the array (11) and the disc (14) is provided with axially extending flanges (12, 13, 15 and 16) at its axial ends. The flanges (12, 13, 15 and 16) are so dimensioned that when the array (11) is mounted on the disc (14) the flanges (12, 13, 15 and 16) engage each other in close fitting relationships in such a way that the array (11) and the disc (14) have an enclosed annular chamber radially spacing them apart. Annular chambers (18, 19) are provided at the interfaces of the confronting flanges (12, 13, 15 and 16), and the regions of the interfaces between the chambers (18) and the free axial ends of the flanges (12, 13, 15 and 16) are sealed by vacuum brazing.

Abstract: A process provides a method for attaching a turbine blade to a blade support such as a rotor or rotor disc of a turbine. The root portion of the blade is formed to a shape approximately that of a groove in the surface of the rotor or rotor disc and the root portion of the blade is inserted within the groove. A composition comprising a particulate compound selected from the group consisting of a ceramic, graphite metal, metal alloy and mixtures thereof is positioned between the root portion of the blade and steeples, located one on either side of the groove.

Abstract: A rotor member for a turbomachine includes a first portion formed of comparatively higher creep rupture strength material, and a second portion integrally joined to the first portion and formed of comparatively higher tensile strength material. The rotor defines a bore and is configured such that the operative environment thereof inflicts higher temperatures upon the first portion, and higher centrifugally-induced stresses upon the second portion. In order to improve the operating speed, burst margin, or both, of the rotor a plurality of circumferentially spaced and annularly arrayed cavities are provided within the rotor at the union of the two portions. The portions are intimately united by hot isostatic pressing (HIP) so that the rotor is of a single piece (monolithic) having portions of selected physical properties appropriate to the thermal/physical stresses imposed thereon, and defining voids which reduce the weight and bore stresses thereof.

Abstract: A bladed turbine disk has a plurality of air cooled blades. The disk has a substantially continuous impervious rim. Each blade has a platform and an impervious base with the cooling air inlet between the platform and base. Each blade base is diffusion bonded to the rim, preferably to a slightly raised plateau. The edge of the bond surface is accessable and free of stress concentration.

Abstract: A rotor has an inner disk member including a web and a circumferential widened outer portion. A blade member has a continuous circumferential inner edge. At least one of the members has a plurality of axially spaced circumferential rings extending toward the other member. The two members are diffusion bonded together. A stiff lightweight assembly is achieved.

Abstract: In a turbine rotor composed of a ceramic turbine blade and a metal shaft with an end to be machined, martensite stainless steel or martensite heat-resistant steel which can be hardened in a gas or vacuum after having been heated beyond the quenching temperature thereof is used as the metal. The ceramic blade and the metal shaft are heat-connected by brazing or shrinkage fit at 800.degree. C., or more. The metal shaft hardened through the heat-connection is tempered only at the end to be machined or the metal shaft heated to the quenching temperature is quench hardened only in part other than the end to be machined, thus facilitating the machining of the metal shaft locally which keeping the remaining part thereof in a quench hardened condition.

Abstract: Two-part turbine-blade retainer structures are disclosed for axial retention of each of a plurality of turbine blades to a rotor wheel, wherein radial retention is via fir-tree engagement of individual blade roots to the wheel. In a preferred embodiment, a male or bolt element of the retainer has a shank which is characterized by a smoothly cylindrical portion adjacent at one end to one of the heads; this cylindrical portion terminates at a shoulder, beyond which the shank is reduced and externally threaded. A sleeve or nut element of the retainer has an elongate threaded bore and is characterized by an outer cylindrical surface which extends to the second head. The two elements are proportioned to be inserted through opposite ends of a passageway and to be screwed together into firm engagement at the shoulder (i.e., at a location intermediate the two heads), with the sleeve covering the threads of the male element and the heads preventing the turbine blade from axial motion with respect to the wheel.

Abstract: Steam turbine blades are fastened in an outer layer of weld material applied by deposit welding to the outer surface of the rotor body, the composition of the weld material being optimally matched with respect to hot strength and/or corrosion resistance, in particular stress corrosion resistance, to the local mechanical, thermal and chemical requirements. A possible option is additionally to insert a deposit welded intermediate layer of medium alloying element content. Steels with 10-14% Cr, low carbon and additions of Mo and possibly V are preferred as the weld material for the layer.