Research on the Corrosion Behavior of Nickel Base Alloy in Municipal Sludge Treated by Supercritical Water Oxidation

2014 ◽  
Vol 1010-1012 ◽  
pp. 220-224 ◽  
Author(s):  
Hong Ma ◽  
Shu Zhong Wang ◽  
Mei Gao ◽  
Sheng Wen
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Supercritical Water ◽  
Water Oxidation ◽  
Base Alloy ◽  
Supercritical Water Oxidation ◽  
Nickel Base Alloy ◽  
Municipal Sludge ◽  
Temperature Zone ◽  
Nickel Base

The corrosion behavior of Nickel base alloy was studied in municipal sludge treated by supercritical water oxidation (SCWO). The results showed that the corrosion rate of Nickel-base alloy Inconel600 in the temperature zone under 460°C is smaller, the surface oxide were mainly Cr2O3. The corrosion rate of Nickel-base alloy Inconel625 in the supercritical temperature zone is smaller, it formed more easily protective layers containing element Ni (main containing NiO and Ni (OH)2) and had good heat resistance at higher temperature.

Study on the Corrosion Behaviour of Nickel-Base Alloy 625 in Landfill Leachate Treated by Supercritical Water Oxidation

2014 ◽  
Vol 908 ◽  
pp. 93-97
Author(s):  
Min Yan Xiao
Keyword(s):  
Supercritical Water ◽  
Landfill Leachate ◽  
Water Oxidation ◽  
Base Alloy ◽  
Oxygen Flux ◽  
Supercritical Water Oxidation ◽  
Nickel Base Alloy ◽  
Alloy 625 ◽  
Corrosion Rates ◽  
Nickel Base

Experiments were conducted to study the corrosion behaviors of nickel-base alloy 625 under various temperature and oxygen fluxes, since severe corrosion always happens in landfill leachate treated by supercritical water oxidation. It indicates that under the condition of various oxygen fluxes, corrosion rates of nickel-base alloy 625 have similar variation, but at different temperature, such variation of corrosion rates can not be found, which implies oxygen fluxes may have more effects on corrosion rate than temperature. Meanwhile, oxide films of nickel-base alloy 625 changed obviously from low oxygen flux to high oxygen flux. The precipitation on the surfaces of alloys are confirmed as NiCrO4, which may form by the combination of dissolved Ni2+ and CrO42-.

Influence of surface modifications on pitting corrosion behavior of nickel-base alloy 718. Part 2: Effect of aging treatment

2014 ◽  
Vol 78 ◽  
pp. 151-161 ◽  
Author(s):  
Ting Chen ◽  
Hendrik John ◽  
Jing Xu ◽  
Qiuhong Lu ◽  
Jeffrey Hawk ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Pitting Corrosion ◽  
Base Alloy ◽  
Aging Treatment ◽  
Surface Modifications ◽  
Alloy 718 ◽  
Nickel Base Alloy ◽  
Nickel Base

Removal Efficiency of Organic Substance in Municipal Sludge by Supercritical Water Oxidation

2013 ◽  
Vol 726-731 ◽  
pp. 1732-1738 ◽  
Author(s):  
Dan Li ◽  
Cong Jun Sun ◽  
Jian Feng Ye
Keyword(s):  
Organic Matter ◽  
Supercritical Water ◽  
Water Oxidation ◽  
Municipal Wastewater ◽  
Wastewater Sludge ◽  
Main Reaction ◽  
Supercritical Water Oxidation ◽  
Municipal Sludge ◽  
Study Results ◽  
Resident Time

In this study efficiency of organic matter in municipal wastewater sludge treated by supercritical water is investigated. Influences of main reaction parameters, including temperature (380~500°C), pressure (23-30 MPa), residence time (1-10 min), oxidant dose (100%-200%), were evaluated. Orthogonal Array design was applied in order to consider each parameters impact on COD removal. Study results indicate that 97.89% of COD in the sludge sample can be removed in 10min at 500°C, 30MPa and 200% H2O2oxidant excess dose. Temperature, pressure, resident time are main factors to affect the reaction, while oxidant dose has a little effect on removal of COD in municipal wastewater sludge. The conclusion is the organic matter in municipal wastewater sludge can be removed effectively by super critical water oxidation.

scholarly journals Decomposition of Municipal Sludge by Supercritical Water Oxidation.

1997 ◽  
Vol 30 (5) ◽  
pp. 813-818 ◽  
Author(s):  
Motonobu Goto ◽  
Takatsugu Nada ◽  
Satoshi Kawajiri ◽  
Akio Kodama ◽  
Tsutomu Hirose
Keyword(s):  
Supercritical Water ◽  
Water Oxidation ◽  
Supercritical Water Oxidation ◽  
Municipal Sludge

Localized corrosion behavior of scratches on nickel-base Alloy 690TT

2011 ◽  
Vol 56 (4) ◽  
pp. 1781-1785 ◽  
Author(s):  
Fanjiang Meng ◽  
En-Hou Han ◽  
Jianqiu Wang ◽  
Zhiming Zhang ◽  
Wei Ke
Keyword(s):  
Corrosion Behavior ◽  
Base Alloy ◽  
Localized Corrosion ◽  
Nickel Base Alloy ◽  
Nickel Base

Parameter Optimization of Municipal Sludge Treated by Supercritical Water Oxidation Process

2014 ◽  
Vol 1010-1012 ◽  
pp. 693-698
Author(s):  
Mei Gao ◽  
Shu Zhong Wang ◽  
Hong Ma
Keyword(s):  
Total Nitrogen ◽  
Residence Time ◽  
Reaction Temperature ◽  
Supercritical Water ◽  
Water Oxidation ◽  
Oxidation Process ◽  
Removal Rate ◽  
Supercritical Water Oxidation ◽  
Municipal Sludge ◽  
Optimum Reaction

Supercritical water oxidation process can effectively degrade the total nitrogen in municipal sludge. In order to obtain the optimum parameters of municipal sludge treated by supercritical water oxidation, this article selected the total nitrogen removal rate as the evaluation value, and used response surface methodology to optimize the parameters of sludge treatment by supercritical water oxidation, the parameters including temperature, pressure, residence time and oxidation coefficient. The results show that the reaction temperature, pressure and residence time exist interaction, and the influence degree of parameters is: pressure > reaction temperature > reaction retention time; The optimum reaction conditions are as follows: reaction temperature 539 °C, pressure 27 MPa, residence time 434 s, and oxidation coefficient 2.16, under these conditions, the total nitrogen decreasing efficiency can reach 74.12%.

scholarly journals Corrosion Behavior of a Nickel-Base Dental Casting Alloy in Artificial Saliva Studied by Weight Loss and Polarization Techniques

2019 ◽  
Author(s):  
Elnaz Moslehifard ◽  
Mahsa Moslehifard ◽  
Sanaz Ghasemzadeh ◽  
Farzad Nasirpouri
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Base Alloy ◽  
Artificial Saliva ◽  
Ph Values ◽  
Significant Difference ◽  
Weight Loss Method ◽  
Loss Method ◽  
Nickel Base

Objectives: Nickel-chromium (Ni-Cr) base dental alloys with desirable properties have been employed in prosthodontics for years. Corrosion behavior of a Ni-Cr base alloy in artificial saliva with different pH values is determined in this work. Materials and Methods: Corrosion behavior of Ni-Cr alloy was studied using weight loss described by corrosion rate (CR) in mils per year (mpy) and potentiodynamic polarization described by corrosion potential (CP) in mV and current density (CD) in mA/cm2 in artificial saliva with different pH. Surface morphology was studied using scanning electron microscopy (SEM). Statistical difference was assessed using one-way ANOVA and post-hoc Tukey's honestly significant difference (HSD) test with a difference significance of 95%. Results: In weight loss method, CR was 71.95±3.40, 17.26±1.03, 8.92±0.35, and 6.93±0.54 mpy at pH values of 2.5, 5, 7, and 9, respectively. CR obtained at pH of 2.5 was significantly different than that in other groups, but those obtained at pH of 5, 7, and 9 were not significantly different. In the polarization method, CP values were significantly different. CD measured at pH of 2.5 and 5 was significantly different than the rest of pH values (P<0.05). CRs at pH of 7 and 9 were not significantly different. SEM exhibited the formation of preferential sites of corrosion attacks influenced by pH. Conclusions: Both techniques revealed consistent results. Corrosion resistance increases as pH increases towards less acidic conditions. In more acidic saliva, the corrosion rate is greater. The less acidic saliva leads to formation of a more stable passive film on Ni, and the dissolution of Ni decreases, leading to lower CRs.

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