A high-temperature centrifuge for creep, rupture, and bend tests

JOM ◽  
1958 ◽  
Vol 10 (3) ◽  
pp. 187-189
Author(s):  
I. I. Kornilov
Keyword(s):  
High Temperature ◽  
Creep Rupture ◽  
Bend Tests

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.

WISCALLOY 25-35Nb

Alloy Digest ◽  
1996 ◽  
Vol 45 (9) ◽  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Creep Rupture ◽  
Centrifugally Cast ◽  
Heat Resistant ◽  
Rupture Properties

Abstract Wiscalloy 25-35Nb is a high-temperature cast heat-resistant stainless steel with good creep-rupture properties. The alloy is centrifugally cast and is often used as petrochemical furnace tubing. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on casting and joining. Filing Code: SS-654. Producer or source: Wisconsin Centrifugal.

Structural Integrity Code and Regulatory Issues in the Design of High Temperature Reactors

2008 ◽  
Author(s):  
William J. O’Donnell ◽  
Amy B. Hull ◽  
Shah Malik
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Structural Integrity ◽  
Cyclic Creep ◽  
Creep Rupture ◽  
Creep Fatigue ◽  
Asme Code ◽  
High Temperature Reactors ◽  
Gen Iv ◽  
Very High

Since the 1980s, the ASME Code has made numerous improvements in elevated-temperature structural integrity technology. These advances have been incorporated into Section II, Section VIII, Code Cases, and particularly Subsection NH of Section III of the Code, “Components in Elevated Temperature Service.” The current need for designs for very high temperature and for Gen IV systems requires the extension of operating temperatures from about 1400°F (760°C) to about 1742°F (950°C) where creep effects limit structural integrity, safe allowable operating conditions, and design life. Materials that are more creep and corrosive resistant are needed for these higher operating temperatures. Material models are required for cyclic design analyses. Allowable strains, creep fatigue and creep rupture interaction evaluation methods are needed to provide assurance of structural integrity for such very high temperature applications. Current ASME Section III design criteria for lower operating temperature reactors are intended to prevent through-wall cracking and leaking and corresponding criteria are needed for high temperature reactors. Subsection NH of Section III was originally developed to provide structural design criteria and limits for elevated-temperature design of Liquid-Metal Fast Breeder Reactor (LMFBR) systems and some gas-cooled systems. The U.S. Nuclear Regulatory Commission (NRC) and its Advisory Committee for Reactor Safeguards (ACRS) reviewed the design limits and procedures in the process of reviewing the Clinch River Breeder Reactor (CRBR) for a construction permit in the late 1970s and early 1980s, and identified issues that needed resolution. In the years since then, the NRC, DOE and various contractors have evaluated the applicability of the ASME Code and Code Cases to high-temperature reactor designs such as the VHTGRs, and identified issues that need to be resolved to provide a regulatory basis for licensing. The design lifetime of Gen IV Reactors is expected to be 60 years. Additional materials including Alloy 617 and Hastelloy X need to be fully characterized. Environmental degradation effects, especially impure helium and those noted herein, need to be adequately considered. Since cyclic finite element creep analyses will be used to quantify creep rupture, creep fatigue, creep ratcheting and strain accumulations, creep behavior models and constitutive relations are needed for cyclic creep loading. Such strain- and time-hardening models must account for the interaction between the time-independent and time-dependent material response. This paper describes the evolving structural integrity evaluation approach for high temperature reactors. Evaluation methods are discussed, including simplified analysis methods, detailed analyses of localized areas, and validation needs. Regulatory issues including weldment cracking, notch weakening, creep fatigue/creep rupture damage interactions, and materials property representations for cyclic creep behavior are also covered.

scholarly journals Creep Rupture Analysis of Candidate Steels for the Traveling Wave Reactor

2018 ◽  
Author(s):  
Cheng Xu
Keyword(s):  
High Temperature ◽  
Yield Stress ◽  
Traveling Wave ◽  
Rupture Strength ◽  
Creep Rupture ◽  
Thermal Creep ◽  
Uniaxial Tensile ◽  
Advantages And Disadvantages ◽  
Analysis Methods ◽  
Best Estimate

TerraPower has developed sophisticated computational analysis tools to support the design and fabrication of high temperature components to be used in the Traveling Wave Reactor (TWR). One of the key material properties required to predict material damage and remaining lifetime of key in-reactor components is the thermal creep rupture time. Although TerraPower optimized ferritic-martensitic (FM) HT9 steel has shown consistent improvement in yield stress and creep rupture strength through uniaxial tensile tests, extrapolations of existing test data are still needed to fully support the complex analysis used in the TWR design. Traditional Larson-Miller analysis for creep rupture was used to compare the TerraPower optimized HT9 steel to the existing historical database. The results of the Larson-Miller analysis were compared to the results from the Wilshire analysis to explore the relative advantages and disadvantages of each method. The best estimate values for fitting constants and activation energies were determined for both methods, taking into account the effects of the higher yield stress observed in TerraPower optimized HT9 compared to historic HT9. Likewise, the best estimate creep rupture stresses for TerraPower optimized HT9 at various times and temperatures were determined by extrapolations using both the Larson-Miller and Wilshire analysis. The allowable stresses of historical and TerraPower optimized HT9 steels were compared to those of existing materials (9Cr-1Mo-V) in the ASME high temperature code. The comparison of analysis methods and rupture stresses demonstrate that TerraPower FM steel thermal creep performance and analysis methods are comparable to existing ASME qualified materials for high temperature applications.

Developing New Cast Austenitic Stainless Steels With Improved High-Temperature Creep Resistance

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Philip J. Maziasz ◽  
John P. Shingledecker ◽  
Neal D. Evans ◽  
Michael J. Pollard
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Creep Strength ◽  
Stainless Steels ◽  
Creep Resistance ◽  
Austenitic Stainless Steels ◽  
Creep Rupture ◽  
Particulate Filter ◽  
Alloy Development ◽  
Wide Range

Oak Ridge National Laboratory and Caterpillar (CAT) have recently developed a new cast austenitic stainless steel, CF8C-Plus, for a wide range of high-temperature applications, including diesel exhaust components and turbine casings. The creep-rupture life of the new CF8C-Plus is over ten times greater than that of the standard cast CF8C stainless steel, and the creep-rupture strength is about 50–70% greater. Another variant, CF8C-Plus Cu/W, has been developed with even more creep strength at 750–850°C. The creep strength of these new cast austenitic stainless steels is close to that of wrought Ni-based superalloys such as 617. CF8C-Plus steel was developed in about 1.5 years using an “engineered microstructure” alloy development approach, which produces creep resistance based on the formation of stable nanocarbides (NbC), and resistance to the formation of deleterious intermetallics (sigma, Laves) during aging or service. The first commercial trial heats (227.5 kg or 500 lb) of CF8C-Plus steel were produced in 2002, and to date, over 27,215 kg (300 tons) have been produced, including various commercial component trials, but mainly for the commercial production of the Caterpillar regeneration system (CRS). The CRS application is a burner housing for the on-highway heavy-duty diesel engines that begins the process to burn-off particulates trapped in the ceramic diesel particulate filter (DPF). The CRS/DPF technology was required to meet the new more stringent emissions regulations in January, 2007, and subjects the CRS to frequent and severe thermal cycling. To date, all CF8C-Plus steel CRS units have performed successfully. The status of testing for other commercial applications of CF8C-Plus steel is also summarized.

Very-Short-Time, Very-High-Temperature Creep Rupture of Type 347 Stainless Steel and Correlation of Data

1969 ◽  
Vol 91 (1) ◽  
pp. 32-38 ◽  
Author(s):  
C. D. Lundin ◽  
A. H. Aronson ◽  
L. A. Jackman ◽  
W. R. Clough
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Minimum Creep Rate ◽  
Creep Rupture ◽  
Aisi Type ◽  
Data Scatter ◽  
Long Time ◽  
Short Time ◽  
Very High ◽  
Rupture Behavior

Available equipment initially developed for welding research studies was used to investigate the creep-rupture behavior of AISI type 347 stainless steel in a very-high-temperature range from 62 to 86 percent of the solidus. Stress applications from 900 to 28,000 psi gave rupture times from a fraction of a second to several hundred seconds with thousandfold variations of minimum creep rate. Results could be presented by conventional means. Data scatter on a Monkman-Grant plot was typical. Correlation and extrapolation procedures developed by Larson-Miller, Manson-Haferd, Dorn, Korchynsky, and Conrad for conventional long-time results were found to be applicable, with preference being given to the Manson-Haferd procedures.

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 Creep Properties of Alloy 690 Steam Generator Tubes at High Temperature Using Tube Specimen

2019 ◽  
Author(s):  
Jongmin Kim ◽  
Woogon Kim ◽  
Minchul Kim
Keyword(s):  
High Temperature ◽  
Steam Generator ◽  
Creep Test ◽  
Rupture Life ◽  
Creep Rupture ◽  
Severe Accident ◽  
High Temperature Creep ◽  
Creep Life ◽  
Temperature Creep ◽  
Alloy 690

Abstract Thermally induced steam generator (SG) tube failures caused by hot gases from a damaged reactor core can result in a containment bypass event and may lead to release of fission products to the environment. A typical severe accident scenario is a station blackout (SBO) with loss of auxiliary feedwater. Alloy 690 which has increased the Cr content has been replaced for the SG tube due to its high corrosion resistance against stress corrosion cracking (SCC). However, there is lack of research on the high temperature creep rupture and life prediction model of Alloy 690. In this study, creep test was performed to estimate the high temperature creep rupture life of Alloy 690. Based on reported creep data and creep test results of Alloy 690 in this study, creep life extrapolation was carried out using Larson-Miller Parameter (LMP), Orr-Sherby-Dorn (OSD), Manson-Haferd Parameter (MHP), and Wilshire’s approach. And a hyperbolic sine (sinh) function to determine master curves in LMP, OSD and MHP methods was used for improving the creep life estimation of Alloy 690 material.

Study on the Creep and Fatigue Properties of CLAM Steel

2014 ◽  
Vol 94 ◽  
pp. 12-16
Author(s):  
Yan Yun Zhao ◽  
Shao Jun Liu ◽  
Chun Jing Li ◽  
Bo Yu Zhong ◽  
Gang Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Structural Material ◽  
Research And Development ◽  
Fatigue Damage ◽  
Creep Rupture ◽  
Fatigue Properties ◽  
Clam Steel ◽  
High Temperature Mechanical Properties ◽  
Key Issues

China Low Activation Martensitic (CLAM) steel has been chosen as the structural material for China ITER Test Blanket Module (TBM). Creep-rupture and fatigue damage caused by high temperature and pulse stresses are two key issues for the final application of CLAM steel in China ITER TBM. In this paper, the research and development progress of the creep and fatigue behaviors of CLAM steel were presented. These results showed that CLAM steel possessed good high temperature mechanical properties.

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