Scanning Electron Microscope of Fatigue and Creep-Fatigue From Stress Concentrations in Plates

2012 ◽  
Author(s):  
Osamu Watanabe ◽  
Marina Kikuchi ◽  
Akihiro Matsuda
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Crack Propagation ◽  
Fatigue Test ◽  
304 Stainless Steel ◽  
High Temperature Fatigue ◽  
Fracture Surfaces ◽  
Creep Fatigue ◽  
Scanning Electron

Fatigue crack propagation forms a distinctive pattern which is observable on the fracture surfaces of materials. Purpose of this study is to analyze the fracture process of the materials received under cyclic distortion loading using scanning electron microscope. The test piece made of type 304 stainless steel with the hole of a different size is examined on the conditions of the high temperature fatigue and creep-fatigue. This study first takes a picture of the fracture with SEM, and measures the intervals of striation on fracture surfaces. Next, this study calculates the number of the crack propagation cycles and compares with the original experimental data defined by the load decrease condition or the crack length. Consequently, there is not so much differences at striation intervals regardless of the size of the root notch radius in the present tests. However, the striation spacing in the creep fatigue test has grown about twice of striation intervals in the high temperature fatigue-test.

scholarly journals Fractal Dimension of Fracture Surface in Rock Material after High Temperature

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Z. Z. Zhang
Keyword(s):  
Fractal Dimension ◽  
Electron Microscope ◽  
High Temperature ◽  
Fracture Surface ◽  
Scanning Electron Microscope ◽  
Fractal Dimensions ◽  
Threshold Value ◽  
Fracture Surfaces ◽  
Increasing Temperature ◽  
Scanning Electron

Experiments on granite specimens after different high temperature under uniaxial compression were conducted and the fracture surfaces were observed by scanning electron microscope (SEM). The fractal dimensions of the fracture surfaces with increasing temperature were calculated, respectively. The fractal dimension of fracture surface is between 1.44 and 1.63. Its value approximately goes up exponentially with the increase of temperature. There is a quadratic polynomial relationship between the rockburst tendency and fractal dimension of fracture surface; namely, a fractal dimension threshold can be obtained. Below the threshold value, a positive correlativity shows between rockburst tendency and fractal dimension; when the fractal dimension is greater than the threshold value, it shows an inverse correlativity.

INVESTIGATION ON HIGH-TEMPERATURE CORROSION BEHAVIOR OF INCONEL 600 UNDER SO2-BEARING GAS AT 650°C

2019 ◽  
Vol 27 (06) ◽  
pp. 1950155
Author(s):  
KWANG-HU JUNG ◽  
SEONG-JONG KIM
Keyword(s):  
Electron Microscope ◽  
Weight Gain ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
High Temperature Corrosion ◽  
X Ray Diffraction ◽  
Oxide Structure ◽  
X Ray ◽  
Inconel 600 ◽  
Scanning Electron

The corrosion characteristics of Inconel 600 were investigated at 650∘C in air and 76%[Formula: see text]%[Formula: see text]%[Formula: see text]%SO2 gas environment up to 500[Formula: see text]h. Specimens exposed to each condition were characterized by weight gain, scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction. The oxide structure consisting of the thin Cr2O3 layer and Cr2O3 nodules was observed, which increased the weight gain of specimens. In the SO2-bearing gas, it showed a bigger weight gain due to the coarsening of Cr2O3 nodules. Therefore, it was suggested that the sulfur-accelerated coarsening of Cr2O3 nodules at the high temperature.

Failure Analysis on Heating Surface Tube Crackof High Temperature Reheater in Station Boiler

2013 ◽  
Vol 804 ◽  
pp. 333-336
Author(s):  
Yun Jian Jiang ◽  
Xiang Feng Zheng ◽  
Rong Gang Xue ◽  
Guo Zhen Dong ◽  
Ji Feng Zhao ◽  
...  
Keyword(s):  
Residual Stress ◽  
Electron Microscope ◽  
High Temperature ◽  
Chemical Analysis ◽  
Scanning Electron Microscope ◽  
Failure Analysis ◽  
Heating Surface ◽  
Welding Residual Stress ◽  
Microscope Analysis ◽  
Scanning Electron

Through methods, such as microscope analysis, chemical analysis, metallography examination and scanning electron microscope etc, the causes resulting in high temperature reheater tube cracking of station boiler have been analyzed. The result indicates the crack is reheat crack, and structure stress, higher hardness and excessive welding residual stress are the primary inducement of tube joint crack.

Local Investigation of Microstructure-Induced Fatigue Damaging

2009 ◽  
Vol 417-418 ◽  
pp. 521-524
Author(s):  
Michael Marx ◽  
Wolfgang Schäf ◽  
Markus T. Welsch ◽  
Horst Vehoff
Keyword(s):  
Electron Microscope ◽  
Crack Initiation ◽  
Scanning Electron Microscope ◽  
Crack Propagation ◽  
Focused Ion Beam ◽  
Fatigue Cracks ◽  
Ion Beam ◽  
Short Crack ◽  
Beam Technique ◽  
Scanning Electron

From the emission of dislocations till short crack propagation fatigue is a local process determined by the microstructure. In this paper we present experiments based on refined applications of the scanning electron microscope and focused ion beam technique, which give detailed information about crack initiation and the interaction of short fatigue cracks with microstructural elements.

Self-Propagating High-Temperature Synthesis of Fe-W(B, C) Based Composite

2013 ◽  
Vol 748 ◽  
pp. 46-50 ◽  
Author(s):  
Saowanee Singsarothai ◽  
Sutham Niyomwas
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
The Self ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis ◽  
Flame Ignition ◽  
Scanning Electron

Fe-W based composite have successfully been prepared using natural resource. The ferberite (Fe (Mn, Sn)WO4) tailings mixed with aluminum, carbon and boron oxide powder were used as reactants. The reactants were pressed and followed by oxy-acetylene flame ignition. The products from the self-propagating high-temperature synthesis (SHS) reaction were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) couple with dispersive X-ray (EDS).

The Influence of the Hydrothermal Conditions on the Morphologies of β-Ni(OH)2

2012 ◽  
Vol 562-564 ◽  
pp. 494-497
Author(s):  
Xiao Ming Fu
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Reaction Time ◽  
Scanning Electron Microscope ◽  
Reaction Temperature ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Low Reaction Temperature ◽  
Scanning Electron

Flower-like β-Ni(OH)2 and nanoflakes have been successfully synthesized with nickel nitrate as nickel source and stronger ammonia water as precipitant via the hydrothermal method. The phase and the morphologies of the samples have been characterized and analyzed by XRD (X-ray diffraction) and SEM (Scanning electron microscope), respectively. XRD shows that the phase of the samples is β-Ni(OH)2. SEM confirms that The low reaction temperature is propitious to the synthesis of flower-like β-Ni(OH)2, and with the increase of the reaction time the nanoflakes of flower-like β-Ni(OH)2 become much thinner. However, The high temperature is in favor of the synthesis of β-Ni(OH)2 nanosflakes, and with the further increase of the reaction temperature.

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