scholarly journals Electrochemical Behaviors of Ni-Base Superalloy CMSX-4 in 3.5 wt.% NaCl: Effect of Temperature and Preoxidation

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5478
Author(s):  
Xianzi Lv ◽  
Quantong Jiang ◽  
Jie Zhang ◽  
Jianxin Zhang ◽  
Zaiwang Huang ◽  
...  
Keyword(s):  
Electrochemical Corrosion ◽  
Effect Of Temperature ◽  
Electrochemical Technique ◽  
Corrosion Mechanism ◽  
X Ray Diffraction ◽  
Corrosion Morphology ◽  
Electrochemical Behaviors ◽  
Different Temperatures ◽  
The Relationship ◽  
Base Superalloy

The electrochemical behaviors of the Ni-base superalloy CMSX-4 were carried out in 3.5 wt.% NaCl solution using electrochemical technique. The electrochemical corrosion process was divided into four stages, and reactions at the alloy surface and corrosion morphology at each stage were analyzed. The passivity mechanism at the stable passivation stage and the occurrence of pitting corrosion at the transpassivation state were discussed especially. The corrosion parameters including Ecorr, Epass, ipass and Epit were compared at different temperatures to reveal the relationship between the temperature and the corrosion resistance properties. The corrosion products were investigated by the aid of X-Ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDS). By designing different preoxidation procedures, the corrosion mechanism of oxide scales was analyzed for the preoxidized samples.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals Influence of Temperature on Mechanical Properties of P(BAMO-r-THF) Elastomer

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2507
Author(s):  
Jinxian Zhai ◽  
Hanpeng Zhao ◽  
Xiaoyan Guo ◽  
Xiaodong Li ◽  
Tinglu Song
Keyword(s):  
Mechanical Properties ◽  
X Ray Diffraction ◽  
Polymeric Chains ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Strain Induced Crystallization ◽  
Thermal Histories ◽  
Static Conditions ◽  
The Relationship ◽  
Induced Crystallization

The relationship between temperature and the mechanical properties of an end cross-linked equal molar random copolyether elastomer of 3,3-bis(azidomethyl)oxetane and tetrahydrofuran (P(BAMO-r-THF)) was investigated. During this investigation, the performances of two P(BAMO-r-THF) elastomers with different thermal histories were compared at different temperatures. The elastomer as prepared at 20 °C (denoted as S0) exhibited semi-crystallization morphology. Wide angle X-ray diffraction analysis indicated that the crystal grains within elastomer S0 result from the crystallization of BAMO micro-blocks embedded in P(BAMO-r-THF) polymeric chains, and the crystallinity is temperature irreversible under static conditions. After undergoing a heating-cooling cycle, this elastomer became an amorphous elastomer (denoted as S1). Regarding mechanical properties, at 20 °C, break strains and stresses of 315 ± 22% and 0.46 ± 0.01 MPa were obtained for elastomer S0; corresponding values of 294 ± 6% and 0.32 ± 0.02 MPa were obtained for elastomer S1. At −40 °C, these strains and stresses simultaneously increased to 1085 ± 21% and 8.90 ± 0.72 MPa (S0) and 1181 ± 25% and 10.23 ± 0.44 MPa (S1), respectively, owing to the strain-induced crystallization of BAMO micro-blocks within the P(BAMO-r-THF) polymeric chains.

Effect of Temperature and H2S Concentration on Corrosion of X52 Pipeline Steel in Acidic Solutions

2013 ◽  
Vol 743-744 ◽  
pp. 589-596 ◽  
Author(s):  
Meng Liu ◽  
Jian Qiu Wang ◽  
Wei Ke
Keyword(s):  
Corrosion Rate ◽  
Pipeline Steel ◽  
Corrosion Products ◽  
Effect Of Temperature ◽  
Corrosion Mechanism ◽  
General Corrosion ◽  
Ferrous Sulfide ◽  
Immersion Corrosion ◽  
Different Temperatures ◽  
Diffraction Patterns

The corrosion behavior of X52 pipeline steel in H2S solutions was investigated through immersion corrosion test which was carried out in a high temperature and high pressure autoclave at different temperatures and H2S concentrations. General corrosion rates were calculated based on the weight loss of samples. The morphology and the chemical composition of the corrosion products were obtained by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The crystal structure of corrosion products was analyzed by X-Ray diffraction patterns (XRD). The corrosion products consisted mainly of the sulfide compounds (mackinawite, cubic ferrous sulfide, troilite and pyrrhotite). The corrosion products included two layers: the inner iron-rich layer and the outer sulfur-rich layer. Under H2S concentrations of 27g/L, the corrosion rate increased with the increase of temperature up to 90°C and then decreased at 120°C, finaly increased again. The corrosion rate first increased with H2S concentrations then decreased at 120°C. The structure and stability of the corrosion products due to different corrosion mechanism had a major impact on the corrosion rate. The corrosion resistance of the corrosion products increased as follows: mackinawite < cubic ferrous sulfide < troilite < pyrrhotite.

Experimental Research on the Thermal Damage of Concrete

2013 ◽  
Vol 351-352 ◽  
pp. 460-466
Author(s):  
Chao Chen ◽  
Ying She Luo ◽  
Song Hua Tang ◽  
Xuan Zhang
Keyword(s):  
Damage Evolution ◽  
Thermal Damage ◽  
Damage Model ◽  
Effect Of Temperature ◽  
Compression Tests ◽  
Thermal Compression ◽  
Relevant Reference ◽  
Different Temperatures ◽  
The Relationship ◽  
Fire Design

In order to investigate the effect of temperature (from normal temperature to 850°C) coursed by fire on the strength damage of concrete, thermal compression tests for concrete specimens named C35 have been performed under different temperature conditions. Emphasis is laid on the relationship between temperature and thermal damage strength; and the relevant formula is proposed in this paper. The regularity and mechanism of thermal damage evolution in concrete on strength under high temperature are analyzed. Combined the result of tests with the residual strength thermal damage model, we obtain the specific damage variable value D under different temperatures. Finally, we compare the fitting formula curve to relevant reference; there are some important conclusions which can be partly applied to fire design of concrete structure.

Microstructure and Growth Mechanism of Glucose-Carburized Nickel Substrates

2013 ◽  
Vol 716 ◽  
pp. 153-158
Author(s):  
E.M. Pechlivani ◽  
G. Stergioudis ◽  
E. Pavlidou ◽  
S. Skolianos ◽  
D. Tsipas
Keyword(s):  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Temperature Treatment ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treatment Conditions ◽  
Nickel Substrates ◽  
Current Densities

In this research, efforts were made to study the modification of microstructure of pure Ni matrices. Modification was attempted using glucose as carburizing medium under a control of heat treatment conditions. Nickel plates were carburized under vacuum conditions at 380°C and 650°C for 3 hours. In order to determine the parameters of the carburizing, thermal properties of glucose along with the thermochemical behavior were examined by Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA). The characterization of the microstructure of the carburized specimens was investigated by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). For analyzing the effect of temperature treatment on corrosion resistance, electrochemical corrosion tests were conducted. It was observed that the polarization curves for carburized samples at 380°C were shifted to lower corrosion current densities. Consequently, lower corrosion rates were achieved for these samples preventing the formation of extensive corrosion over their surfaces comparing with carburized Nickel substrates at 650°C.

Effect of Temperature on the Purity, Particle Size and Morphology of Fe2O3 Nanomaterials

2014 ◽  
Vol 895 ◽  
pp. 305-308 ◽  
Author(s):  
Abdul Rahman Noor Azreen ◽  
Norlida Kamarulzaman ◽  
Nurhanna Badar ◽  
Mustaffa Nur Amalina ◽  
Kamarudin Norashikin
Keyword(s):  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Xrd Pattern ◽  
Weak Organic Acid ◽  
Irregular Shapes ◽  
Three Samples ◽  
Different Temperatures ◽  
Particle Size And Morphology ◽  
Size And Morphology

Iron Oxide, Fe2O3, has extensively been studied by many researchers because of their important uses for various applications such as magnetic storages, catalysts, anode, gas sensors and biomedical applications. In our work, Fe2O3 have been synthesized via a new self-propagating combustion (SPC) route using a weak organic acid as an oxidant. The precursor was annealed at three different temperatures. Three samples of Fe2O3 heated at 300 °C, 600 °C and 800 °C for 24 hours were characterized using X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The XRD pattern confirms that the crystal structure for both 600 °C and 800 °C samples are rhombohedral while for the 300 °C sample, rhombohedral and cubic phases are present. The SEM images showed that the 300 °C and 600 °C materials have irregular shapes. For the 800 °C sample the materials seem to be more crystalline with individual polyhedral shapes.

scholarly journals Surface Modification of Zinc with an Oxime for Corrosion Protection in Chloride Medium

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ganesha Achary ◽  
Y. Arthoba Naik
Keyword(s):  
Electrochemical Corrosion ◽  
Corrosion Mechanism ◽  
Protective Film ◽  
Electron Transfer Rate ◽  
Organic Solution ◽  
Immersion Method ◽  
Chloride Medium ◽  
Aqueous Sodium Chloride Solution ◽  
Corrosion Studies ◽  
Different Temperatures

The surface treatment of zinc was done with different concentrations of an oxime (2E)-2-(hydroxylamino)-1,2-diphenylethanol molecule by the immersion method. The electrochemical corrosion studies of surface-treated zinc specimens were performed in aqueous sodium chloride solution (1 M, pH 5.0) at different temperatures in order to study the corrosion mechanism. The recorded electrochemical data indicated a basic modification of the cathodic corrosion behavior of the treated zinc resulting in a decrease of the electron transfer rate. The zinc samples treated by immersion in the inhibiting organic solution presented good corrosion resistance. Using scanning electron microscopy (SEM), it was found that a protective film was formed on the surface of zinc.

Effect of Temperature on Structure and Corrosion Resistance of Oxide Scale on Hot Rolled Strip

2010 ◽  
Vol 152-153 ◽  
pp. 229-237
Author(s):  
Xian Liang Zhou ◽  
Min Zhu ◽  
Xiao Zhen Hua ◽  
Zhi Guo Ye ◽  
Qing Jun Chen
Keyword(s):  
Oxide Scale ◽  
Electrochemical Impedance ◽  
Effect Of Temperature ◽  
Rolled Strip ◽  
X Ray Diffraction ◽  
Hot Rolled Strip ◽  
Treatment Processes ◽  
Different Temperatures ◽  
Coiling Process ◽  
Hot Rolled

Various structure scales at the surface of SS400 hot rolled strip were fabricated by heat treatment processes involving different temperatures. A simulation about the effect of various temperatures on the oxide scale structure during the coiling process was carried out. The structure and corrosion behavior of different oxide scales formed at the surface of hot rolled strip were investigated in sodium bisulfite (NaHSO3) solution by scanning electron microscope (SEM), X-ray diffraction (XRD), polarization curves and electrochemical impedance spectroscopy (EIS). The scale prepared at 550 °C is mainly composed of one layer of Fe3O4 phase. The scales prepared at 600 °C and 700 °C consist of the outer thin Fe2O3 layer and the inner (Fe3O4+Fe particles) layer. The scale prepared at 650 °C is mainly composed of Fe3O4 phase as well as a spot of Fe2O3 phase. The thickness of scale prepared at 650°C is observed to be more homogeneous than that of other scales and the bonding between the scale and substrate is found to be very strong. The experimental results clearly reveal that the hot rolled strip with scale prepared at 650 °C exhibits the most excellent corrosion resisting property in 0.01 mol/L NaHSO3 solution.

Corrosion Inhibition Mechanism of Magnetic Field on Carbon Steel

2010 ◽  
Vol 152-153 ◽  
pp. 353-356
Author(s):  
Peng Zhang ◽  
Gang Chen ◽  
Bin Guo ◽  
Shu Kang Cheng
Keyword(s):  
Magnetic Field ◽  
Corrosion Rate ◽  
Sea Water ◽  
Electrochemical Corrosion ◽  
Water Relation ◽  
Corrosion Products ◽  
Alternating Magnetic Field ◽  
Inhibition Mechanism ◽  
X Ray Diffraction ◽  
Corrosion Morphology

The current research explores the effect of alternating magnetic field on corrosion rate and products compositions of 45 steel, by use of electrochemical test, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The calculated inhibition efficiency of the alternating magnetic field based on electrochemical corrosion rate is up to 16.66%. Electrochemical corrosion morphology and surface products were also discussed. The surface of specimen is uniform and compact in magnetized sea water relation to that in 3.5% NaCl solution and sea water. The corrosion products of 45 steel in sea water are FeCl2•4H2O, Fe(OH)3 and FeOOH. However, the corrosion products of 45 steel in magnetized sea water are FeOOH, Fe3O4 and FeCl3•6H2O chiefly.

Effect of Growth Temperature on the Indium Incorporation in InGaN Epitaxial Films

2011 ◽  
Vol 287-290 ◽  
pp. 1456-1459 ◽  
Author(s):  
P. C Chang ◽  
C. L Yu ◽  
Y. W Jahn ◽  
S. J Chang ◽  
K. H Lee
Keyword(s):  
Optoelectronic Devices ◽  
Chemical Vapor ◽  
Epitaxial Films ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Film Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Peak Emission

InxGa1-xN epilayers have been grown by metalorganic chemical vapor deposition (MOCVD) at different temperatures between 740°C to 830°C. The thickness of InGaN film is 50nm for all samples. The incorporation of indium is found to increase with decreasing grown temperature. The optical properties and film quality of the samples have been investigated by photoluminescence (PL) system and X-ray diffraction (XRD). The Full Width at Half Maximum (FWHM) of PL and XRD decreases with increasing the grown temperature. We also found that the peak emission of PL shifts with changing the grown temperature. The effect of temperature on the film properties was determined. This understanding will lead to better quality control of the optoelectronic devices.

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