The Study of Surface Longitudinal Crack on SPA-H Steel Slab by CSP

2013 ◽  
Vol 798-799 ◽  
pp. 190-196
Author(s):  
Qi Chun Peng ◽  
Jian Zou ◽  
Lei Qiu ◽  
Zhi Bo Tong ◽  
Wei Xiong
Keyword(s):  
Electron Microscope ◽  
Thermal Stress ◽  
High Temperature ◽  
Static Pressure ◽  
Longitudinal Crack ◽  
Metallographic Analysis ◽  
Steel Slab ◽  
Mould Powder ◽  
Equiaxial Crystal ◽  
Scanning Electron

By the means of Metallographic analysis, scanning electron microscope (SEM), and energy spectrum analysis, the development of SPA-H surface middle longitudinal crack was studied. To find out the causes of the longitudinal crack, statistical method was adopted. The result shows that, the generating process of longitudinal crack was: the changing of mould powder owing to Ti and Al element, low overheating degree, and bad slag smelting, which leading to bad transfer heat of slab and depression. For the thermal stress of solidifying contraction, molten steel static pressure, and mould friction, the stress concentration was produced in the weak place of solidified shell, for example, in the small equiaxial crystal less than 1mm. the cracking occurred when the stress more than allow strength of high temperature slab.

scholarly journals High Temperature Degradation Mechanism of Concrete with Plastering Layer

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 398
Author(s):  
Chihao Liu ◽  
Jiajian Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Decomposition ◽  
Electron Microscope ◽  
High Temperature ◽  
Thermogravimetric Analysis ◽  
Degradation Mechanism ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Scanning Electron

At present, the research on the high temperature degradation of concrete usually focuses on only the degradation of concrete itself without considering the effect of the plastering layer. It is necessary to take into account the influence of the plastering layer on the high temperature degradation of concrete. With an increase in the water/cement ratio, the explosion of concrete disappeared. Although increasing the water/cement ratio can alleviate the cracking of concrete due to lower pressure, it leads to a decrease in the mechanical properties of concrete after heating. It is proved that besides the water/cement ratio, the apparent phenomena and mechanical properties of concrete at high temperature can be affected by the plastering layer. The plastering layer can relieve the high temperature cracking of concrete, and even inhibit the high temperature explosion of concrete with 0.30 water/cement ratio. By means of an XRD test, scanning electron microscope test and thermogravimetric analysis, it is found that the plastering layer can promote the rehydration of unhydrated cement particles of 0.30 water/cement ratio concrete at high temperature and then promote the mechanical properties of concrete at 400 °C. However, the plastering layer accelerated the thermal decomposition of C-S-H gel of concrete with a water/cement ratio of 0.40 at high temperature, and finally accelerate the decline of mechanical property of concrete. To conclude, the low water/cement ratio and plastering layer can delay the deterioration of concrete at high temperature.

Influence of Mn and Ni on Austenite Stabilization during a High Temperature Q&P Treatment

2021 ◽  
Vol 1016 ◽  
pp. 379-384
Author(s):  
Eider Del Molino ◽  
Teresa Gutierrez ◽  
Mónica Serna-Ruiz ◽  
Maribel Arribas ◽  
Artem Arlazarov
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
High Temperature ◽  
Retained Austenite ◽  
Nickel Content ◽  
X Ray Diffraction ◽  
Quenching And Partitioning ◽  
X Ray ◽  
Scanning Electron ◽  
P Cycle

The aim of this work was to study the influence of quenching and partitioning temperatures combined with various levels of Mn and Ni contents on the austenite stabilization along the quenching and partitioning (Q&P) cycle. Three steels with 2 wt.%, 4 wt.% and 6 wt.% manganese and one steel with 2 wt.% nickel content were investigated. Phase transformation temperatures and critical cooling rates were obtained experimentally using dilatometer for each alloy. Q&P cycles with different quenching and partitioning temperatures were also done in dilatometer, thus, allowing monitoring of the expansion/contraction during the whole Q&P cycle. Microstructure characterization was performed by means of a Scanning Electron Microscope and X-Ray Diffraction to measure retained austenite content. It was found that, strongly depending on the Q&P conditions, austenite stabilization or decomposition occurs during partitioning and final cooling. In case of high partitioning temperature cycles, austenite reverse transformation was observed. Certain cycles resulted in a very effective austenite stabilization and interesting microstructure.

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.

Analysis of Intragranular Misorientation Related to Deformation in an Al-Mg-Mn Alloy

2005 ◽  
Vol 495-497 ◽  
pp. 1049-1054 ◽  
Author(s):  
Yoshimasa Takayama ◽  
Jerzy A. Szpunar ◽  
Hajime Kato
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Room Temperature ◽  
Electron Back Scatter Diffraction ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Stored Energy ◽  
Kernel Average Misorientation ◽  
Dislocation Glide ◽  
Scanning Electron

Intragranular misorientation reflects strain generated during deformation with dislocation glide. The SEM/EBSP (scanning electron microscope/ electron back scatter diffraction pattern) technique provides is “kernel average misorientation (KAM)” as the most appropriate quantity to evaluate the strain or the stored energy for a given point. The KAM is defined for a given point as the average misorientation of that point with all of its neighbors. In the present paper two analyses of the intragranular misorientation using the SEM/EBSP technique for a cyclic deformation at room temperature and a high temperature deformation in an Al-Mg-Mn alloy are reviewed.

Studying on High Temperature Thermoplastic of High Carbon Steel

2014 ◽  
Vol 809-810 ◽  
pp. 384-389
Author(s):  
Lang He ◽  
Yu Tang
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Melting Point ◽  
Liquid Phase ◽  
Energy Dispersive Spectrometer ◽  
High Carbon Steel ◽  
Optical Microscope ◽  
High Carbon ◽  
Solid Liquid ◽  
Scanning Electron

High temperature thermoplastic of 50Mn2V casting slab was tested by Gleeble-1500 thermal simulator machine. The morphology, microstructure and composition of fracture surfacewere observed and analyzed by optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The results show that, there are two brittle temperature zones of 50Mn2V casting slab at the temperature of 600~950°C and 1300~1465°C, respectively, The section shrinkaging rate is less than 60%. The fracture mode changes from mixed one dominated by intergranular to toughness transgranular one with the increase of temperature at the range of 600~1250°C. However, the fracture is along with the solid-liquid phase at the range of 1300°C~ melting point.

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.

Sign in / Sign up

Export Citation Format

Share Document