Effects of Thermal Exposure on Microstructure and Mechanical Properties of Ni Based Superalloy GTD111

2011 ◽  
Vol 275 ◽  
pp. 31-34 ◽  
Author(s):  
Han Sang Lee ◽  
Keun Bong Yoo ◽  
Doo Soo Kim ◽  
Jae Hoon Kim
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Operating Temperature ◽  
Rupture Strength ◽  
Mechanical Test ◽  
Thermal Exposure ◽  
Creep Rupture Strength ◽  
Material Degradation ◽  
Temperature Dependent ◽  
Hot Gas

The rotating components in the hot sections of land-based gas turbine are exposed to severe environment during several ten thousand hours at above 1100 oC operating temperature. The failure mechanism of the hot gas components would be accompanied by material degradation in the properties of high temperature and creep rupture strength. Many hot gas components in gas turbine are made of Ni-based superalloy because of their high temperature performance. In this work, we surveyed the time and temperature dependent degradation of Ni-based superalloy. We prepared the specimens from GTD111 that are exposed at 871 oC and 982 oC in 1,000 ~ 10,000 hours. We carried out the mechanical test and microstructural observation.

Effects of High Temperature Deformation and Thermal Exposure on Microstructure and Mechanical Properties of Co-Based Superalloy

2011 ◽  
Vol 275 ◽  
pp. 121-123
Author(s):  
Han Sang Lee ◽  
Keun Bong Yoo ◽  
Kyu So Song ◽  
Kyu Ho Lee
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Mechanical Test ◽  
Thermal Exposure ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
High Temperature Strength ◽  
Material Degradation ◽  
Temperature Dependent ◽  
Combustion Gas

The gas turbine components operated in hot combustion gas undergo material degradation due to the thermal cycles. The failure mechanism of the hot gas components would be accompanied by material degradation in the properties of high temperature strength and creep rupture time. Many stationary parts in gas turbine are made of Co-based superalloy because of their high temperature performance. In this work, we survey the time and temperature dependent degradation of Co-based superalloy. We prepared the specimens of Co-based superalloy ECY768 that are exposed at 871 and 982 oC in 1000 ~ 5000 hours. We carried out the mechanical test and microstructural observation.

Degradation Characteristics of Inconel738LC with Thermal Exposure

2011 ◽  
Vol 275 ◽  
pp. 117-120
Author(s):  
Keun Bong Yoo ◽  
Han Sang Lee ◽  
Kyu So Song
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Stress Rupture ◽  
Thermal Exposure ◽  
High Temperature Strength ◽  
Material Degradation ◽  
Temperature Dependent ◽  
Microstructural Investigation ◽  
Combustion Gas ◽  
Hot Gas

Gas turbine components operated by hot combustion gas undergo material degradation due to the thermal cycle by daily startup and shutdown. The failure mechanism of the hot gas components is accompanied by degradation in the properties of high temperature strength and creep rupture time. Many hot gas components in gas turbines are made of Ni-based superalloy because of their high temperature performance. In this work, we survey the time and temperature dependent degradation of Ni-based superalloy. We prepared specimens from Inconel738LC that were then exposed at 871~982°C in 1,000~5,000hours. We carried out stress-rupture tests and microstructural investigation.

KUBOTA ALLOY KHR35C

Alloy Digest ◽  
1999 ◽  
Vol 48 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Rupture Strength ◽  
Creep Rupture ◽  
Creep Rupture Strength ◽  
Temperature Performance

Abstract Kubota alloy KHR35C is similar to HP alloy with the addition of niobium to increase its creep-rupture strength. Typical applications include components and assemblies for severe carburizing environments, such as ethylene pyrolysis coils. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as casting and joining. Filing Code: SS-753. Producer or source: Kubota Metal Corporation.

Progress in the Design of an Improved High-Temperature 1 Percent CrMoV Rotor Steel

1990 ◽  
Vol 112 (1) ◽  
pp. 99-115 ◽  
Author(s):  
R. L. Bodnar ◽  
J. R. Michael ◽  
S. S. Hansen ◽  
R. I. Jaffee
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Room Temperature ◽  
Rupture Strength ◽  
Temper Embrittlement ◽  
Creep Rupture ◽  
Rotor Steel ◽  
Creep Rupture Strength ◽  
Austenitizing Temperature ◽  
Creep Ductility

Silicon-deoxidized, tempered bainitic 1 percent CrMoV steel is currently used extensively for high-temperature steam turbine rotor forgings operating at temperatures up to 565°C due to its excellent creep rupture properties and relative economy. There is impetus to improve the creep rupture strength of this steel while maintaining its current toughness level and vice versa. The excellent creep rupture ductility of the low Si version of this steel allows the use of a higher austenitizing temperature or tensile strength level for improving creep rupture strength without loss in creep ductility or toughness. When the tensile strength of this steel is increased from 785 to 854 MPa, the creep rupture strength exceeds that of the more expensive martensitic 12CrMoVCbN steel currently used for high-temperature rotor applications where additional creep rupture strength is required. The toughness of 1 percent CrMoV steel is improved by lowering the bainite start (Bs) temperature in a “superclean” base composition which is essentially free of Mn, Si, P, S, Sb, As and Sn. The Bs temperature can be lowered through the addition of alloying elements (i.e., C, Ni, Cr, and Mo) and/or increasing the cooling rate from the austenitizing temperature. Using these techniques, the 50 percent FATT can be lowered from approximately 100°C to below room temperature, which provides the opportunity to eliminate the special precautionary procedures currently used in the startup and shutdown of steam turbines. The most promising steels in terms of creep rupture and toughness properties contain 2.5 percent Ni and 0.04 percent Cb (for austenite grain refinement and enhanced tempering resistance). In general, the creep rupture strength of the superclean steels equals or exceeds that of the standard 1 percent CrMoV steel. In addition, the superclean steels have not been found to be susceptible to temper embrittlement, nor do they alter the room temperature fatigue crack propagation characteristics of the standard 1 percent CrMoV steel. These new steels may also find application in combination high-temperature-low-temperature rotors and gas turbine rotors.

Evaluation of Short Term Creep-Rupture Strength of High Temperature P122 Boiler Material

2003 ◽  
Author(s):  
John Pumwa
Keyword(s):  
High Temperature ◽  
Fracture Mode ◽  
Life Prediction ◽  
Rupture Strength ◽  
Creep Rupture ◽  
Creep Rupture Strength ◽  
Short Term ◽  
Boiler Material ◽  
Term Creep ◽  
Short Term Creep

The complex thermal-mechanical loading of power-generating plant components usually comprises of creep, high-cycle and low-cycle fatigue which are thermally induced by start-ups, load changes and shut-downs, producing instationary temperature gradients and hence creating strain as well as stress fields. In order to select the correct materials for these hostile environmental conditions, it is vitally important to understand the behaviour of mechanical properties such as creep rupture properties of these materials. This paper reports the results of standard creep rupture tests of P122 (HCM12A or 12Cr-1.8W-1.5Cu) high temperature boiler material. P122 is one of the latest developed materials for high temperature environments, which has the potential to be successful in hostile environments. The tests were conducted at temperatures ranging from 550°C to 700°C at 50°C intervals with stress levels ranging from 80–400 MPa using a locally made creep rupture testing machine. The results are found to have stable creep-rupture strength at short term creep stage for over 800-hours at elevated temperatures. Creep life prediction from Larson-Miller relationship was also carried out and the accuracy of life prediction is demonstrated. Moreover, the fracture mode assessments strongly revealed a typical ductile transgranular fracture mode with dimples and voids.

IN-738

Alloy Digest ◽  
1972 ◽  
Vol 21 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Chromium Content ◽  
Rupture Strength ◽  
Base Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Creep Rupture Strength ◽  
Temperature Performance ◽  
Nickel Base

Abstract IN-738 is a vacuum cast, precipitation hardened, nickel-base alloy possessing excellent high temperature creep-rupture strength combined with hot corrosion resistance superior to that of many present day high-strength superalloys of lower chromium content. This datasheet provides information on composition, physical properties, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Ni-172. Producer or source: Licensees of International Nickel.

BOEHLER L311 VMR

Alloy Digest ◽  
2007 ◽  
Vol 56 (5) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Gas Turbine ◽  
Nickel Alloy ◽  
Rupture Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Scaling Resistance ◽  
Specialty Metals

Abstract Boehler L311 VMR is a nickel alloy having high creep and rupture strength up to 760 deg C (1400 deg F) and scaling resistance in air to 850 deg C (1560 deg F). It is used in the aircraft and gas turbine industries as shafts, blades, and discs. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-650. Producer or source: Böhler-Uddeholm Specialty Metals Inc.

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