Fracture Analysis of Pneumatic Control Valve Rod Used for Nuclear Power Plants

2014 ◽  
Vol 1004-1005 ◽  
pp. 1359-1364
Author(s):  
Lei Yang ◽  
Yan Li ◽  
Lu Zhang ◽  
Yun Ting Lai ◽  
Zhi Feng Luo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Impact Test ◽  
Control Valve ◽  
Fracture Analysis ◽  
Pneumatic Control ◽  
Scanning Electron

The fracture of a carbon steel pneumatic control valve rod used for Nuclear Power Plants was analyzed in terms of the microstructure, inclusions and fractogragh by means of tensile test, charpy V-Notch impact test, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The results indicated that the fracture of the rod is induced by the unqualified chemical composition: a large number of inclusions which distribute in grain boundaries reduce the material plasticity and toughness, and eventually cause fracture.

scholarly journals Treatment of fly ash from power plants using thermal plasma

2017 ◽  
Vol 8 ◽  
pp. 1043-1048 ◽  
Author(s):  
Sulaiman Al-Mayman ◽  
Ibrahim AlShunaifi ◽  
Abdullah Albeladi ◽  
Imed Ghiloufi ◽  
Saud Binjuwair
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fly Ash ◽  
Thermal Plasma ◽  
Inductively Coupled Plasma ◽  
Power Plants ◽  
Plasma Reactor ◽  
Atomic Emission ◽  
Inductively Coupled ◽  
Scanning Electron

Fly ash from power plants is very toxic because it contains heavy metals. In this study fly ash was treated with a thermal plasma. Before their treatment, the fly ash was analyzed by many technics such as X-ray fluorescence, CHN elemental analysis, inductively coupled plasma atomic emission spectroscopy and scanning electron microscopy. With these technics, the composition, the chemical and physical proprieties of fly ash are determined. The results obtained by these analysis show that fly ash is mainly composed of carbon, and it contains also sulfur and metals such as V, Ca, Mg, Na, Fe, Ni, and Rh. The scanning electron microscopy analysis shows that fly ash particles are porous and have very irregular shapes with particle sizes of 20–50 μm. The treatment of fly ash was carried out in a plasma reactor and in two steps. In the first step, fly ash was treated in a pyrolysis/combustion plasma system to reduce the fraction of carbon. In the second step, the product obtained by the combustion of fly ash was vitrified in a plasma furnace. The leaching results show that the fly ash was detoxified by plasma vitrification and the produced slag is amorphous and glassy.

Research on the Effect of Holding Time on Diamond Drill Bit Performance

2013 ◽  
Vol 634-638 ◽  
pp. 2411-2418
Author(s):  
Ru Yin Song ◽  
Hong Wu Yang ◽  
Jun De Yang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Hot Pressing ◽  
Sintering Temperature ◽  
Fracture Analysis ◽  
Holding Time ◽  
Drill Bit ◽  
Diamond Drill ◽  
Scanning Electron

The sintering parameters of hot-pressing diamond drill bit mainly contains the sintering temperature, holding time, sintering pressure and the pressurized method. The length of holding time is directly related to the performance of diamond drill bit. This article mainly discusses the effect of holding time on the performance of diamond drill bit. First, a general formula of diamond drill bit is chosen. A group of samples in this parameter were loaded and sintered. Holding time is set as variable, while other parameters remain the same. The optimal holding time for this formula is obtained through the mechanical properties tests on the samples’ bending, tension, compression, and hardness, and fracture analysis using scanning electron microscopy (SEM).

Impact and Thermal Properties of Unsaturated Polyester (UPR) Composites Filled with Empty Fruit Bunch Palm Oil (EFBPO) and Cellulose

2014 ◽  
Vol 896 ◽  
pp. 310-313 ◽  
Author(s):  
Elmer Surya ◽  
Michael ◽  
Halimatuddahliana ◽  
Maulida
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Palm Oil ◽  
Impact Test ◽  
Unsaturated Polyester ◽  
Empty Fruit Bunch ◽  
Infra Red ◽  
The Matrix ◽  
The Impact ◽  
Scanning Electron

In this research, the impact properties of unsaturated polyester (UPR) composites filled with empty fruit bunch palm oil (EFBPO) and cellulose were investigated. The composites were made by hand-lay up method by mixing UPR with the content of each fillers (EFBPO and cellulose) of 5,10,15,20 wt.%. The parameter which was carried out on the prepared samples was impact test. It was found that the addition of fillers to the matrix caused the impact strength of composites increased at 10% addition of EFBPO and 5% addition of cellulose. The results were confirmed by fourier transform infra-red (FTIR) and supported by thermogravimetric analysis (TGA) and scanning electron microscopy (SEM).

Using of Microspheres of Power Ashes for Gases Cleaning from Sulphur Dioxide

2014 ◽  
Vol 1079-1080 ◽  
pp. 110-117
Author(s):  
V.S. Yemelyanova ◽  
H. Kurokawa ◽  
B.T. Dossumova ◽  
Zh.K. Kairbekov ◽  
T.V. Shakiyeva ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Analysis ◽  
Iron Content ◽  
Power Plants ◽  
Iron Ions ◽  
Chemical Methods ◽  
Physical Chemical ◽  
Composition And Structure ◽  
Scanning Electron

The composition and structure of the microspheric aluminosilicates of Combined Heating and Power Plants (CHРP) ashes is studied with the help of modern physical-chemical methods (XRD, scanning electron microscopy, BET, elemental and chemical analysis). The activity of microsphere-based catalysts for the reaction of Na2SO3 oxidation by oxygen is also studied by kinetic and potentiometric methods. By means of EPR and Möessbauer spectroscopy it is concluded that iron ions into the composition of cenospheres exist in two states – Fe3+ and Fe2+, thus, the iron (III) is in the form of solitary ions in an aluminosilicate matrix in the range of the iron content 3-4 mass %.

Study of Creep Cavitation in a Stainless Steel Weldment Using Small Angle Neutron Scattering and Scanning Electron Microscopy

2014 ◽  
Author(s):  
H. Jazaeri ◽  
P. J. Bouchard ◽  
M. T. Hutchings ◽  
P. Lindner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Stainless Steel ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Nuclear Power ◽  
Creep Cavitation ◽  
Scanning Electron

Strain-relief cracking, also referred to as reheat cracking, is a generic creep failure mode that has been observed in many welded stainless steel structures operating at high temperatures in UK nuclear power plant. One of the challenges currently faced by nuclear utility EDF Energy is the need to predict, with high certainty, the life-time of ageing engineering plant operating in the creep regime. A study of creep cavities near a reheat crack, ∼28 mm long, in an AISI Type 316H austenitic stainless steel header is reported. The cracked component was removed after 65,000 hours operation at a mean temperature of 525°C in a nuclear power plant. Creep cavities in the vicinity of the crack are observed using scanning electron microscopy (SEM) and found to be mainly surrounding inter-granular carbides. Optimized metallographic and image analysis procedures are used to quantify the size and area fraction of creep cavities as a function of distance from the crack along a line normal to the crack face. Small angle neutron scattering (SANS) is used to quantify creep cavitation, averaged over a large gauge volume, ∼20 mm3, at similar positions normal to the crack line. A systematic increase in the true fractional size distribution of cavities is observed approaching the crack. The cavity size distribution peaks between 100–300 nm diameter and this correlates closely with the quantitative metallography results of cavities in this sample. SANS has the advantage of being non-destructive and also the examined volume is several mm3, against an area of hundreds of μm2 in the case of SEM, therefore giving more statistically significant results. However the two techniques are complementary, as the detailed microscopic information from SEM is required to interpret the SANS data.

Agglomeration of High Calcium Fly Ash for Utilization II. Binding Mechanisms

1989 ◽  
Vol 178 ◽  
Author(s):  
Carol L. Kilgour ◽  
Kenneth L Bergeson ◽  
Scott Schlorholtz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Power Plants ◽  
Layer Structure ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Fly Ashes ◽  
High Calcium ◽  
Scanning Electron

AbstractFly ashes from the Lansing and Ottumwa power plants in Iowa were agglomerated by means of a continuous pan agglomerator, a continuous auger and a batch turbine agglomerator. In order to compare agglomeration mechanisms the following parameters were determined: (a) particle size distributions of the untreated fly ashes; (b) particle size distributions of the agglomerated fly ashes; (c) pore size distribution of agglomerates; (d) crystalline hydration products by X-ray diffraction; and (e) morphological characterization by scanning electron microscopy.In the batch system coalescence mechanisms were favoured. The agglomerates were fairly irregular in shape and had a rough surface texture. As residence time in the system increased breakage of agglomerates occurred, reducing the average agglomerate size. In the continuous systems layering of the fine feed particles onto established agglomerates was the predominant growth mechanism. The agglomerates were smooth and spherical. The layer structure was observed by scanning electron microscopy. Agglomerates of widely varying size, strength, and pore matrix can be produced in both systems. It is envisaged that while agglomerates could be produced with characteristics essential for their proposed end use by either method, continuous pan agglomeration would be the most versatile system to utilize.

scholarly journals Fracture analysis of the circulating pump bolts

2020 ◽  
Vol 213 ◽  
pp. 02017
Author(s):  
Chengjun Jiang ◽  
Wei Wang ◽  
Xiaohui Zou ◽  
Jifeng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Power Plant ◽  
Stress Corrosion ◽  
Optical Microscopy ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Fracture Analysis ◽  
Chloride Ions ◽  
Scanning Electron

The microstructure, micrograph of the fracture sections and the alloy elements distribution of the fractured flange-connecting bolts of 3# circulating pump in a power plant were analyzed by the scanning electron microscopy, the optical microscopy and the electron probe microanalysis. The results showed that the failed bolts’ material is not the design material, and failure of the bolts is due to the stress corrosion crack propagation of the bolts’ austenitic material by chloride ions in seawater.

An Investigation of Fluidized Bed Combustion By-Products from Four Iowa Power Plants

1991 ◽  
Vol 245 ◽  
Author(s):  
Carol L. Kilgour
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Power Plants ◽  
Size Distributions ◽  
Fluidized Bed Combustion ◽  
X Ray Diffraction ◽  
X Ray ◽  
By Products ◽  
Scanning Electron

ABSTRACTFluidized bed combustion (FBC) residues from four Iowa power plants were characterized to provide background with respect to chemical, physical, mineralogical and microstructural parameters that might affect their utilization potential. Methodologies used include: bulk chemical analysis; grain size analysis; specific gravity determination; mineralogical analysis by x-ray diffraction; scanning electron microscopy; and thermal analysis.Chemical analysis of the major components showed the separation of the constituents during combustion. The bottom ash is derived from the calcined and partly sulfated limestone, thus the concentration of calcium and sulfur compounds is greater. The fly ash however is derived mostly from the coal and therefore exhibits higher concentrations of coal ash components such as silica (SiO2), alumina (Al2O3), and ferric oxide (Fe2O3). The alkalis appear to be more concentrated in the fly ash.The measured particle size distributions of the bulk samples varied greatly, from extremely coarse (mean particle size ˜2000 μm) to fine (mean particle size ˜25 μm). The size distributions also varied in breadth. Specific gravities values recorded ranged from about 2.65 to about 3.05.X-ray diffraction analyses showed that most of the FBC by-products contain, as easily detectable crystalline components, only quartz, anhydrite and lime, and as is to be expected due to the low combustion temperatures, do not show broad peaks characteristic of glass in conventional fly ashes. Scanning electron microscopy revealed the FBC by-products to be extremely intricate mixtures of particles of complex and variable composition and internal structure.FBC by-products are shown to be extremely complex mixtures of particles of variable composition and internal structure. However, despite their local variation, useful results can be obtained by overall chemical and physico-chemical analyses of their composition. The exploitable properties of FBC residue include the somewhat cementitious nature and the granularity. However, their heterogeneous nature, lack of pozzolanic properties, and elevated sulfate content may limit their uses, especially in construction.

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