Abstract: A dovetail joint between a rotor wheel and a bucket includes a male dovetail component on the rotor wheel and a female dovetail component in the bucket. The male dovetail component has axially projecting hooks with slanted crush surfaces along generally radially inwardly directed surfaces. The slanted surfaces form included angles with neck portions parallel to a plane normal to the axis of rotation which are larger than 90.degree. and decrease in included angle from the radially outermost hooks to the radially innermost hook where the angle is 90.degree.. Compound fillets are also provided along the transition surfaces between the slanted crush surfaces and the neck surfaces. Thus, stress concentrations are minimized.

Abstract: A method for repairing the rim of a steam turbine rotor, and a weld material for repairing such rotors. The method generally includes the steps of removing a damaged rim and its associated dovetail region, so as to form a surface at the perimeter of the rim portion. A weld repair region is then formed on the surface, which is machined to reconstruct the rim portion and the dovetail region exclusively with the weld repair region. Thereafter, an appropriately configured blade is secured to the rim portion with the dovetail region. The method is particularly intended for the repair of a steel alloy rotor, such as a NiCrMoV, NiMoV and CrMoV alloy, while the weld repair is formed with a nickel-base superalloy whose mechanical and thermal properties are compatible with the repair method and the steel alloy over a broad temperature range.

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.