General Electric Company

Robin Carl Schwant

Swami Ganesh

Ling Yang

John Zhiqiang Wang

Francis Alexander Reed

Robert V Falsetti

Jeffrey Allen Hawk

Thomas Joseph Farineau

Robert Edward Deallenbach

Peter W Schilke

Michael Patrick Manning

Steven Louis Breitenbach

Joseph John Pepe

Afina Lupulescu

Christine M Kipphut

A rotor, a steam turbine having a rotor, and a method of producing a rotor are disclosed. The rotor disclosed includes a shaft high pressure section. The high pressure section includes a first high pressure section, a second high pressure section, the second high pressure section being joined to the first pressure section, and a third high pressure section, the third high pressure section being joined to the second high pressure section. At least a portion of the second high pressure section is formed of a high-chromium alloy steel comprising 0.1-1.2 wt % of Mn, up to 1.5 wt % of Ni, 8.0-15.0 wt % of Cr, up to 4.0 wt % of Co, 0.5-3.0 wt % of Mo, 0.05-1.0 wt % of V, 0.02-0.5 wt % of Nb, 0.005-0.15 wt % of N, up to 0.04 wt % of B, up to 3.0 wt % of W, and balance Fe and incidental impurities.

Rotor, a steam turbine and a method for producing a rotor

A method of making a turbine rotor is disclosed. The method includes forming a last stage disk preform having a disk axis, the preform having a rotor face and an opposed shaft face, the rotor face having a circumferential, axially-extending rotor rib protruding therefrom, the shaft face having a circumferential, axially-extending shaft rib protruding therefrom, the disk preform comprising a disk preform material. The method also includes joining the rotor rib to a rotor preform to form a rotor joint, the rotor preform comprising a rotor preform material. The method further includes joining the shaft rib to a shaft to form a shaft joint, the shaft comprising a shaft material, wherein the disk preform material is different than the rotor preform material and the shaft material.

Turbine disk preform, welded turbine rotor made therewith and methods of making the same

Disclosed herein is a method of treating a component comprising solution treating the component for a period of about 4 to about 10 hours at a temperature of about 1750 to about 1850&#xb0; F.; cooling the component to a temperature of about 1490 to about 1520&#xb0; F. at an average rate of 1&#xb0; F./min to about 25&#xb0; F./min; stabilizing the component at about 1450 to about 1520&#xb0; F. for a period of from about 1 to about 10 hours; cooling the component to room temperature; precipitation aging the component by heating the component to a first precipitation aging temperature of about 1275 to about 1375&#xb0; F. for about 3 to about 15 hours; cooling the component at an average rate of 50 to about 150&#xb0; F./hour to a second precipitation aging temperature of about 1100 to about 1200&#xb0; F. for a time period of about 2 to about 15 hours; and cooling the component.

Heat treatment method and components treated according to the method

Disclosed herein is a method of treating a component comprising solution treating the component for a period of about 4 to about 10 hours at a temperature of about 1750 to about 1850&#xb0;F.; cooling the component to a temperature of about 1580 to about 1650&#xb0;F. at an average rate of 1&#xb0;F./min to about 25&#xb0;F./min; stabilizing the component at about 1580 to about 1650&#xb0;F. for a period of about 1 to about 10 hours; cooling the component to room temperature; precipitation aging the component at a first precipitation aging temperature of about 1275 to about 1375&#xb0;F. for about 3 to about 15 hours; cooling the component at an average rate of 50 to about 150&#xb0;F./hour to a second precipitation aging temperature of about 1100 to about 1200&#xb0;F. for a time period of about 2 to about 15 hours; and cooling the component.

A process and alloy for producing a turbine blade whose properties enable the blade to operate within a steam turbine at maximum operating temperatures of greater than 1300&#xb0; F. (about 705&#xb0; C.). The process includes casting the blade from a gamma prime-strengthened nickel-base superalloy having a composition of, by weight, 14.25-15.75% cobalt, 14.0-15.25% chromium, 4.0-4.6% aluminum, 3.0-3.7% titanium, 3.9-4.5% molybdenum, 0.05-0.09% carbon, 0.012-0.020% boron, maximum 0.5% iron, maximum 0.2% silicon, maximum 0.15% manganese, maximum 0.04% zirconium, maximum 0.015% sulfur, maximum 0.1% copper, balance nickel and incidental impurities, and an electron vacancy number of 2.32 maximum. The casting then undergoes a high temperature solution heat treatment to promote resistance to hold-time cracking. The blade exhibits a combination of yield strength, stress rupture properties, environmental resistance, and cost in steam turbine applications to 1400&#xb0; F. (about 760&#xb0; C.).

Process and alloy for turbine blades and blades formed therefrom

A method of making a multiple alloy, multi-section welded turbine rotor includes providing a forged multiple alloy rotor section having an integral microstructure, the rotor section comprising a first alloy having a first alloy composition and second alloy having a second alloy composition, a first weld face comprising the first alloy on a first end and an a second weld face comprising the second alloy on an opposed second end. The method also includes providing a first rotor section comprising the first alloy composition and a second rotor section comprising the second alloy composition. The method also includes welding the first rotor section to the first weld face and welding the second rotor section to the second weld face.

Multiple alloy turbine rotor section, welded turbine rotor incorporating the same and methods of their manufacture

A method of heat treating an Ni-base superalloy article is disclosed. The method includes hot-working an article comprising an NiCrMoNbTi superalloy comprising, in weight percent, at least about 55 Ni to produce a hot-worked microstructure; solution treating the article at a temperature of about 1600&#xb0; F. to about 1750&#xb0; F. for about 1 to about 12 hours to form a partially recrystallized warm-worked microstructure; and cooling the article. The method also includes precipitation aging the article at a first precipitation aging temperature of about 1300&#xb0; F. to about 1400&#xb0; F. for a first duration of about 4 hours to about 12 hours; cooling the article to a second precipitation aging temperature; precipitation aging the article at a second precipitation aging temperature of about 1150&#xb0; F. to about 1200&#xb0; F. for a second duration of about 4 hours to about 12 hours; and cooling the article from the second precipitation aging temperature to an ambient temperature.

Method of heat treating a Ni-based superalloy article and article made thereby

A process for producing a rotor, the rotor formed thereby, as well as turbines in which such a rotor is installed. The rotor is formed by casting an ingot to have first and second regions formed of different alloys that intermix during casting to define a transition zone therebetween. The ingot is forged to yield a rotor forging that contains axially-aligned first and second alloy regions and a transition zone therebetween. The effects of the transition zone can be mitigated by modeling the transition zone and then off-center machining the forging so that the axis of rotation of the machined monolithic rotor is more centrally located with respect to the transition zone.

Process for producing a rotor

A method of processing a rotor. The rotor is formed by casting an ingot to have first and second regions formed of different alloys that intermix during casting to define a transition zone therebetween. The ingot is forged to yield a rotor forging that contains axially-aligned first and second alloy regions and a transition zone therebetween. A three-dimensional approximation of the transition zone is generated, which can be used to predict the effects of the transition zone on the dynamic performance of a rotor machined from the forging.

Method of processing a multiple alloy rotor

Multiple alloy rotor and method therefor

A monolithic rotor comprising first and second rotor regions axially aligned within the monolithic rotor and a transition zone therebetween. The first and second rotor regions are formed of different alloys and the transition zone having a composition that differs from and varies between the first and second rotor regions. The first rotor region is located within a high pressure region of the monolithic rotor and is formed from an alloy chosen from the group consisting of CrMoV low alloy steels, martensitic stainless steels containing about 11 to about 14 weight percent chromium, Fe&#x2014;Ni alloys, and nickel-base alloys. The second rotor region is located within a low pressure region of the monolithic rotor and is formed from an alloy chosen from the group consisting of NiCrMoV low alloy steels and martensitic stainless steels containing about 11 to about 14 weight percent chromium.

Multiple alloy rotor

A heat treatment process is provided that produces a monoblock, low alloy steel rotor for use in low pressure steam turbines. The process includes austenitizing the rotor at a substantially uniformly applied treatment temperature of about 840&deg; C., quenching the rotor, and then differentially tempering the rotor at different axial locations. The rotor is tempered in a furnace divided into regions by refractory boards enabling different temperatures in each divided region to be maintained. A higher than normal strength condition is achieved in one or more axial locations along the rotor by subjecting the location(s) to a lower tempering temperature. The axial location(s) being tempered at lower temperature approximate those locations less susceptible to stress corrosion cracking whereby increased strength is provided the rotor without increasing net susceptibility to stress corrosion cracking.

High strength steam turbine rotor and methods of fabricating the rotor without increased stress corrosion cracking

A high purity martensitic stainless steel alloy containing only critically limited amounts of minor elements including manganese, silicon, tin, phosphorus, aluminum, antimony and arsenic has high strength and toughness and unique resistance to both reversible and irreversible embrittlement.

Growing community of inventors

Pattersonville, NY, United States of America

Robin Carl Schwant