High Temperature Erosion-Oxidation Behavior of Thermally Sprayed NiCr Based Alloy and Cermets Coatings

2006 ◽  
Vol 530-531 ◽  
pp. 117-125 ◽  
Author(s):  
Clarice Terui Kunioshi ◽  
Olandir Vercino Correa ◽  
Lalgudi Venkataraman Ramanathan
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Fluidized Bed ◽  
Oxidation Behavior ◽  
Steel Substrate ◽  
Alumina Powder ◽  
High Temperature Erosion ◽  
Thermally Sprayed ◽  
Scanning Electron

The erosion-oxidation (E-O) behavior of high velocity oxy fuel (HVOF) sprayed Ni20Cr alloy as well as WC and Cr3C2 cermet coatings on a steel substrate were studied. The E-O tests were carried out in a rig with specimen assemblies that were rotated through a fluidized bed of erodent particles in the temperature range 500-850°C and with erodent impact velocities of 2.5-19.5 ms-1. Alumina powder (~200Am) was used as the erodent. The E-O resistance of the coatings was determined as wastage, as a function of temperature. The three coatings did not exhibit any significant change in E-O at temperatures up to 500-600°C. At higher temperatures, wastage increased with temperature, reached a maximum at 700°C and then decreased with further increase in temperature. Different E-O regimes were identified. The specimen surfaces were examined in a scanning electron microscope and their roughness determined. E-O maps have been drawn that define conditions under which the coatings undergo low, moderate and severe wastage.

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.

INFLUENCE OF TEMPERING ON THE MICROSTRUCTURE PERFORMANCE OF THE LASER-TREATED COATINGS ON 45 STEEL

2013 ◽  
Vol 20 (05) ◽  
pp. 1350048 ◽  
Author(s):  
Xiaodong Hu ◽  
Yajiang Li
Keyword(s):  
Residual Stress ◽  
Wear Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Steel Substrate ◽  
Laser Alloying ◽  
Micro Hardness ◽  
Transmission Electron ◽  
Intensity Transfer ◽  
Scanning Electron

Effect of the tempering on the microstructures and tribological properties of the laser alloying coatings is investigated. Laser alloying of the T - Co 50/ TiC mixed powders on a 45 steel substrate can form a hard composite coating, which increased the micro-hardness and wear resistance of the substrate greatly. Such laser alloying coating was investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Experimental results indicate that the tempering is able to remove the accumulation of the residual stress in a certain extent, improving the plastic and toughness properties of such coating; moreover, tempering also improves greatly the formation mechanism, making the coating have enough ability of the intensity transfer, which is beneficial in preventing the crack propagation of the interface in such coating, leading to an improvement of the wear resistance.

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.

scholarly journals An investigation into experimental in situ scanning electron microscope (SEM) imaging at high temperature

2020 ◽  
Vol 91 (6) ◽  
pp. 063702 ◽  
Author(s):  
Rhiannon Heard ◽  
John E. Huber ◽  
Clive Siviour ◽  
Gary Edwards ◽  
Ed Williamson-Brown ◽  
...  
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Sem Imaging ◽  
Scanning Electron

Preparation of Magnetic Abrasive by Sintering Method

2010 ◽  
Vol 135 ◽  
pp. 382-387
Author(s):  
Zeng Dian Zhao ◽  
Yu Hong Huang ◽  
Yu Gang Zhao
Keyword(s):  
Surface Roughness ◽  
Electron Microscope ◽  
High Temperature ◽  
Scanning Electron Microscope ◽  
Energy Dispersive Spectrometer ◽  
Performance Testing ◽  
Ferromagnetic Phase ◽  
Durability Analysis ◽  
Sintering Method ◽  
Scanning Electron

In this paper, ferrosilicon powder was used as the ferromagnetic phase, corundum powder as the abrasive phase, high temperature inorganic binder as the adhesive, and after the ferrosilicon powder was modified, a series of magnetic abrasive was obtained by sintering method. Scanning electron microscope (SEM) and Energy dispersive spectrometer (EDS) were respectively used to characterize the morphology and elemental composition of magnetic abrasive. and through experiments carried out on the magnetic abrasive grinding performance testing and durability analysis. The experimental results showed that the magnetic abrasive prepared had good polishing ability and longer using time, and the surface roughness of the grinding sample can reach 0.12μm and the using time is up to 25 min.

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