scholarly journals Strategies Regarding High-Temperature Applications w.r.t Strength, Toughness, and Fatigue Life for SA508 Alloy

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1953
Author(s):  
Muhammad Raies Abdullah ◽  
Cai Hongneng ◽  
Fang Liang
Keyword(s):  
Fatigue Life ◽  
Treatment Process ◽  
Elevated Temperatures ◽  
Alloy Composition ◽  
Energy Resource ◽  
Secondary Phases ◽  
Steel Composition ◽  
Rpv Steel ◽  
Equilibrium Calculations ◽  
Reactor Pressure

In this work, the stabilities of secondary phases, including carbides, brittle phases, and inclusions, were simulated by computational thermodynamics. Calphad strategical optimization is preferable for all steel alloys regarding energy resource consumption during manufacturing and processing. The alloy composition has been changed to enhance the strength, hardenability, and longevity of a reactor pressure vessel (RPV) steel by computing the phase equilibrium calculations and predicting mechanical properties such as yield and tensile strengths hardness and martensitic and bainitic volume fractions. The stabilities of the pro-eutectoid carbides (cementite), inclusions, and brittle phases in SA508 steel are critical to the toughness and fatigue life related to the crack initiation and expansion of this steel. Overall, the simulations presented in this paper explain the mechanisms that can affect the fatigue resistance and toughness of steel and offer a possible solution to controlling these properties at elevated temperatures by optimizing the steel composition and heat treatment process parameters.

Effects of Neutron Irradiation on the Mechanical and Electromagnetic Properties of Reactor Pressure Vessel Steels

2017 ◽  
Author(s):  
Li Chengliang ◽  
Shu Guogang ◽  
Chen Jun ◽  
Liu Yi ◽  
Liu Wei ◽  
...  
Keyword(s):  
Neutron Irradiation ◽  
Pressure Vessel ◽  
Power Plants ◽  
Hysteresis Loops ◽  
Reactor Pressure Vessel ◽  
Electromagnetic Properties ◽  
Irradiation Damage ◽  
Indentation Hardness ◽  
Rpv Steel ◽  
Reactor Pressure

The effect of neutron irradiation damage of reactor pressure vessel (RPV) steels is a main failure mode. Accelerated neutron irradiation experiments at 292 °C were conducted on RPV steels, followed by testing of the mechanical, electrical and magnetic properties for both the unirradiated and irradiated steels in a hot laboratory. The results showed that a significant increase in the strength, an obvious decrease in toughness, a corresponding increase in resistivity, and the clockwise turn of the hysteresis loops, resulting in a slight decrease in saturation magnetization when the RPV steel irradiation damage reached 0.0409 dpa; at the same time, the variation rate of the resistivity between the irradiated and unirradiated RPV steels shows good agreement with the variation rates of the mechanical properties parameters, such as nano-indentation hardness, ultimate tensile strength, yield strength at 0.2% offset, upper shelf energy and reference nil ductility transition temperature. Thus, as a complement to destructive mechanical testing, the resistivity variation can be used as a potentially non-destructive evaluation technique for the monitoring of the RPV steel irradiation damage of operational nuclear power plants.

Mechanical Property and Oxidation Behavior of LPS-SiC Materials

2006 ◽  
Vol 321-323 ◽  
pp. 913-916
Author(s):  
Sang Ll Lee ◽  
Yun Seok Shin ◽  
Jin Kyung Lee ◽  
Jong Baek Lee ◽  
Jun Young Park
Keyword(s):  
Mechanical Property ◽  
Fracture Toughness ◽  
Oxidation Behavior ◽  
Elevated Temperatures ◽  
Indentation Test ◽  
Bending Test ◽  
Secondary Phases ◽  
Three Point Bending ◽  
Different Temperatures

The microstructure and the mechanical property of liquid phase sintered (LPS) SiC materials with oxide secondary phases have been investigated. The strength variation of LPS-SiC materials exposed at the elevated temperatures has been also examined. LPS-SiC materials were sintered at the different temperatures using two types of Al2O3/Y2O3 compositional ratio. The characterization of LPS-SiC materials was investigated by means of SEM with EDS, three point bending test and indentation test. The LPS-SiC material with a density of about 3.2 Mg/m3 represented a flexural strength of about 800 MPa and a fracture toughness of about 9.0 MPa⋅√m.

Low-Cycle Fatigue Life Prediction in GTD-111 Superalloy at Elevated Temperatures

2011 ◽  
Vol 35 (7) ◽  
pp. 753-758 ◽  
Author(s):  
Ho-Young Yang ◽  
Jae-Hoon Kim ◽  
Keun-Bong Yoo ◽  
Han-Sang Lee ◽  
Young-Soo You
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Fatigue Life Prediction ◽  
Cycle Fatigue

scholarly journals Fatigue Damage Accumulation Modeling of Metals Alloys under High Amplitude Loading at Elevated Temperatures

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1030 ◽  
Author(s):  
Jarosław Szusta ◽  
Andrzej Seweryn
Keyword(s):  
Fatigue Life ◽  
Fatigue Damage ◽  
Damage Accumulation ◽  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
High Amplitude ◽  
Metal Alloys ◽  
Damage State ◽  
State Variable ◽  
Fatigue Damage Accumulation

This article presents an approach related to the modeling of the fatigue life of constructional metal alloys working under elevated temperature conditions and in the high-amplitude load range. The article reviews the fatigue damage accumulation criteria that makes it possible to determine the number of loading cycles until damage occurs. Results of experimental tests conducted on various technical metal alloys made it possible to develop a fatigue damage accumulation model for the LCF (Low Cycle Fatigue) range. In modeling, the material’s damage state variable was defined, and the damage accumulation law was formulated incrementally so as to enable the analysis of the influence of loading history on the material’s fatigue life. In the proposed model, the increment of the damage state variable was made dependent on the increment of plastic strain, on the tensile stress value in the sample, and also on the actual value of the damage state variable. The model was verified on the basis of data obtained from experiments in the field of uniaxial and multiaxial loads. Samples made of EN AW 2024T3 aluminum alloy were used for this purpose.

scholarly journals Assessment of thermal fatigue life for 316L and P91 pipe components at elevated temperatures

2016 ◽  
Vol 168 ◽  
pp. 73-91 ◽  
Author(s):  
Karl-Fredrik Nilsson ◽  
Franceso Dolci ◽  
Thomas Seldis ◽  
Stefan Ripplinger ◽  
Aleksander Grah ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Thermal Fatigue ◽  
Elevated Temperatures ◽  
Thermal Fatigue Life

Additive Manufacturing of Nickel-Based Superalloys

2018 ◽  
Author(s):  
Benjamin Graybill ◽  
Ming Li ◽  
David Malawey ◽  
Chao Ma ◽  
Juan-Manuel Alvarado-Orozco ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
High Performance ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Secondary Phases ◽  
Treatment Regimens ◽  
Operating Environments ◽  
Manufacturing Technologies

Additive manufacturing enables the design of components with intricate geometries that can be manufactured with lead times much shorter when compared with conventional manufacturing. The ability to manufacture components out of high-performance metals through additive manufacturing technologies attracts industries that wish to develop more complex parts, but require components to maintain their structural integrity in demanding operating environments. Nickel-based superalloys are of particular interest due to their excellent mechanical, creep, wear, and oxidation properties at both ambient and elevated temperatures. However, relationship between process parameters and the resulting microstructure is still not well understood. The control of the microstructure, in particular the precipitation of secondary phases, is of critical importance to the performance of nickel-based superalloys. This paper reviews the additive manufacturing methods used to process nickel-based superalloys, the influence of the process parameters on microstructure and mechanical properties, the effectiveness of various heat treatment regimens, and the addition of particles in order to further improve mechanical properties.

Microstructure and Creep Properties of Casting Mg-8Al-0.3Mn Alloy Containing Ca and Sr

2011 ◽  
Vol 189-193 ◽  
pp. 1386-1392
Author(s):  
Yan Lou ◽  
Luo Xing Li
Keyword(s):  
Grain Boundaries ◽  
Creep Resistance ◽  
Elevated Temperatures ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Creep Tests ◽  
Creep Properties ◽  
Calcium Addition ◽  
Order Of Magnitude ◽  
Cast Microstructure

Microstructures and creep properties of AM80 alloy with calcium and strontium additions have been investigated by using OM, X-ray diffraction, SEM and creep tests. The results indicate that the as-cast microstructure of the AM80 alloy consists of the α-Mg matrix, bones-shaped Mg17Al12 and lamellar second precipitation phase at grain boundaries. Calcium and strontium can refine the grain size and the secondary phases. Calcium addition results in the formation of a fishbone Al2Ca eutectic phase in AM80 alloy. With the increase of calcium, reticular Al2Ca phase distribute at the grain boundaries. The creep resistance of the AM80 alloy is significantly improved by a small amount of strontium and calcium addition due to the formation of a grain boundary network consisting of the high melting point Al2Ca phase. Microstructure observations performed on the sample after creep testing reveal that the phase is distorted during creep, reflecting its formation in the as-cast microstructure is unbeneficial to creep properties of the AM80 alloy. The creep resistance of the alloy at elevated temperatures was remarkably increased when calcium was added combined with strontium. The highest creep resistance was obtained from the alloy with xSr and y3Ca addition and its steady state creep rate reached as low as 3.941×10-8s-1, one order of magnitude lower than that of alloy AM80 without strontium and calcium additions.

Nondestructive SANS Study of Reactor Pressure Vessel Steel after Irradiation

2006 ◽  
Vol 321-323 ◽  
pp. 1667-1670
Author(s):  
Young Soo Han ◽  
Eun Joo Shin ◽  
Baek Seok Seong ◽  
Chang Hee Lee ◽  
Duck Gun Park
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Pressure Vessel ◽  
Small Angle Neutron Scattering ◽  
Reactor Pressure Vessel ◽  
Pressure Vessel Steel ◽  
Rpv Steel ◽  
Induced Defects ◽  
Irradiation Induced Defects ◽  
Reactor Pressure

The irradiation induced defects of irradiated reactor pressure vessel(RPV) steel were investigated by a small angle neutron scattering. The degradation of the mechanical properties of RPV steels during an irradiation in a nuclear power plant is closely related to the irradiation induced defects. The size of these defects is known to be a few nanometers, and the small angle neutron scattering technique is regarded as the best non destructive technique to characterize the nano sized inhomogeneities in bulk samples. The RPV steel was irradiated in the HANARO reactor in KAERI. The small angle neutron scattering experiments were performed at SANS instrument in the HANARO reactor. Both unirradiated and irradiated RPV steels were measured and the SANS data of both steels were compared. The nano sized irradiation induced defects were quantitatively analyzed by SANS. The type of defects was also analyzed based on the SANS results, and the effect of the chemical composition of the RPV steel on the irradiation induced defects was discussed.

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