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US 6,152,697 AGranted
Steam turbine different material welded rotor
AssigneeMitsubishi Heavy Industries, Ltd.
InventorsTetsu Konishi, Ryotaro Magoshi
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AssigneeMitsubishi Heavy Industries, Ltd.
InventorsTetsu Konishi, Ryotaro Magoshi
Estimating the term…
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. Thus, the materials are less expensive and inspection of the weld portions becomes facilitated by the inspection holes 7, 8 and the cavity portions 5, 6.
A steam turbine different material welded rotor constructed by rotors divided into a high temperature portion and a low temperature portion and made of different materials being jointed together by welding, wherein a circular recess portion is provided in a central portion of an end face to be jointed of each of said rotors, an annular end face of a peripheral portion of said end face is jointed by welding to an annular end face of an adjacent one of said rotors so that a cavity portion is formed in the central portion of said end faces so jointed and an inspection hole is provided passing through from a rotor outer surface to said cavity portion.
Dependencies are inferred from the claim text.