Corrosion studies under conditions of thermal desalination. II. The influence of oxygen content, pH value, flow rate and impurities on the corrosion rates of unalloyed and low alloyed steels

1978 ◽  
Vol 29 (12) ◽  
pp. 783-791 ◽  
Author(s):  
E. Heitz ◽  
R. Manner
Keyword(s):  
Oxygen Content ◽  
Flow Rate ◽  
Ph Value ◽  
Corrosion Rates ◽  
Corrosion Studies ◽  
Thermal Desalination ◽  
Value Flow

Corrosion Behavior and Mechanism of Oil Casing Steel in CO2 Salt Solution

2021 ◽  
Vol 1035 ◽  
pp. 534-538
Author(s):  
Xiao Jun Fang ◽  
Li Liu ◽  
Zhi Gang Yang ◽  
Yong Qiang Zhang
Keyword(s):  
Carbon Dioxide ◽  
Corrosion Rate ◽  
Oxygen Content ◽  
Metal Surface ◽  
Flow Rate ◽  
Salt Solution ◽  
Ph Value ◽  
Metal Corrosion ◽  
Protective Film ◽  
Static Conditions

The influence of temperature, flow rate, PH value, and oxygen content on the corrosion law in the carbon dioxide salt solution of J55 oil casing was investigated by the corrosion weight loss method. The results showed that with the increase of temperature, the corrosion rate of J55 steel first increased and then decreased and the corrosion rate reached the maximum at 100°C. The corrosion rate was closely related to the formation of corrosion products. The increase of the flow rate speeded up the transfer rate of the corrosive medium to the metal surface and hindered the formation of FeCO3 on the metal surface. The corrosion rate was significantly higher than the corrosion rate under static conditions, and as the flow rate increased, the corrosion rate of J55 steel increased accordingly. The increase of the pH value gradually reduced the concentration of hydrogen ions, and cathodic reaction of hydrogen ion depolarization during metal corrosion process was inhibited, and the tendency to form an oxidizing protective film on the surface of carbon steel increased, thereby reducing the corrosion rate of metals. With the increase of oxygen content, there were both hydrogen evolution reaction of CO2 and oxygen absorption reaction caused by O2 in the cathode process. The corrosion rate of J55 steel gradually increased, and at the same oxygen content, the higher the carbon dioxide content, the greater the corrosion rate is.

Characterizations and Process Parameters of Titanium Dioxide Thin Film by RF Sputtering

2013 ◽  
Vol 22 ◽  
pp. 9-21 ◽  
Author(s):  
Chii Rong Yang ◽  
Tun Ping Teng ◽  
Yun Yu Yeh
Keyword(s):  
Thin Films ◽  
Oxygen Content ◽  
Flow Rate ◽  
Gas Flow ◽  
Deposition Time ◽  
Photocatalytic Performance ◽  
Oxidation Process ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
Oxygen Ratio

In this study, we successfully combined RF magnetron sputtering of a pure Ti metal target and one-stage oxidation process with a wider oxygen ratio (10%-90%) and total sputtering flow rate (16-24 sccm) to produce TiO2thin films on a glass substrate. The crystallization, morphology, roughness, and thickness of the thin films were examined using XRD, HR-FESEM, AFM, and a profilometer. Subsequently, the photocatalytic performance was examined using a spectrometer and video tensiometer. The experimental results show that the TiO2thin films with a majority of anatase and higher roughness exhibit superior photocatalytic performance; the total sputtering gas flow rate of 18 sccm and oxygen content at 10% is the optimal option. Finally, an empirical formula to correlate the film thickness with deposition time was conducted for the sputtering flow rate of 18 sccm and the oxygen content of 10%.

Aluminium corrosion studies. II. Corrosion rates in water

1977 ◽  
Vol 30 (4) ◽  
pp. 721 ◽  
Author(s):  
A Berzins ◽  
JV Evans ◽  
RT Lowson
Keyword(s):  
Corrosion Rate ◽  
Dissolved Oxygen ◽  
Chloride Concentration ◽  
Chloride Ions ◽  
Oxide Surface ◽  
Corrosion Rates ◽  
Saturated Water ◽  
Corrosion Studies ◽  
Competitive Action ◽  
Ph Range

The corrosion rate of aluminium in flowing neutral waters at 50�C has been determined as a function of pH, oxygen concentration and chloride concentration. The corrosion rate, At, as total aluminium lost between the 4th and 80th day was observed to be logarithmic according to At = B log t+C with a minimum rate in the pH range 5-6, and with B c. 3 x 10-5g cm2, C c. 20 x 10-5 g cm-2 and t in days for oxygen-saturated water. Saturating the water with nitrogen or adding up to 15 mg Cl- l-1 increased the corrosion rate. It was concluded that this was due to competitive action on the oxide surface, between dissolved oxygen and chloride ions.

Laboratory and Plant Applications of Recording Electrical Resistance Corrosion Meters

CORROSION ◽  
1960 ◽  
Vol 16 (6) ◽  
pp. 265t-270t ◽  
Author(s):  
E. C. WINEGARTNER
Keyword(s):  
Process Design ◽  
Electrical Resistance ◽  
Corrosion Test ◽  
Laboratory Tests ◽  
Careful Consideration ◽  
Chemical Processes ◽  
Corrosion Rates ◽  
The Past ◽  
Corrosion Studies ◽  
Equipment Laboratory

Abstract The application to plant and laboratory corrosion studies of instruments which continuously record the thickness of corrosion test probes is discussed. A discussion of the instrument components involved and general precautions necessary to obtain meaningful results is included. Careful consideration of design features of the test probes is required in order that they be installed properly to obtain the type of information desired. The use of the electrical resistance method for determining corrosion rates has been increasing rapidly during the past five years. Continuous recording of the results of such tests makes it possible to determine when corrosion occurs in order that additional studies can be made to show how it occurs. Several plant applications of the method are described which demonstrate the usefulness and reliability of the equipment. Laboratory tests which are described not only demonstrate the usefulness of the equipment for corrosion studies but also show that good indications of the presence and concentration of transient corrosive intermediates may be obtained. Such measurements have aided in identifying chemical reactions occurring in chemical processes being developed, and have influenced the process design of the commercial plants. 2.4.2

Physical and Biological Conditions in Heavily Fertilized Water

1934 ◽  
Vol 1 (1) ◽  
pp. 67-93 ◽  
Author(s):  
M. W. Smith
Keyword(s):  
Oxygen Content ◽  
Ph Value ◽  
Cow Manure ◽  
Light Conditions ◽  
Concrete Walls ◽  
Number Of Species ◽  
Large Production ◽  
Experimental Pond

The physical and biological conditions in an experimental pond with concrete walls containing 33 cubic metres of water, initially fertilized with approximately 450 kg. (1000 lb.) of cow manure, were studied intermittently during four years. There was a large production of plankton, but it was subject to marked and sudden fluctuations, and the number of species found was not large. The fertilization caused extreme variations in the light conditions, oxygen content and pH value of the water.

scholarly journals Characteristics of Saliva in FK Ukrida Students After Chewing Paraffin, Xylitol and Sucrose Gum

2021 ◽  
Vol 5 (1) ◽  
pp. 24-30
Author(s):  
Wan Aishah Fariha Binti Wan Nazri ◽  
William Daud ◽  
Flora Rumiati
Keyword(s):  
Flow Rate ◽  
Ph Value ◽  
Salivary Flow ◽  
Reducing Sugar ◽  
Salivary Flow Rate ◽  
Resistant Bacteria ◽  
Chewing Gum ◽  
Ph Values ◽  
Salivary Ph ◽  
Sugar Levels

Data from the Ministry of Health of the Republic of Indonesia in 2009 shows that national sugar consumption per capita reaches 12kg / year. Snacks consumed mostly were based on sucrose sugar and it turns out that sucrose is increasing the insidens of caries because sugar-based foods and drinks cause acid-resistant bacteria to obtain a suitable environment for growth. To overcome this problem sucrose was replaced with alcohol sugar such as xylitol, especially in chewing gum. However, it is still unknown the effect of xylitol on saliva. The purpose of this study was to see whether there were differences in salivary characteristics after consuming paraffin, xylitol chewing gum and sucrose chewing gum by looking at salivary pH values, reducing sugar levels in saliva and salivary flow rates. Saliva collection is done by spitting method then the total volume is divided by the time of collection to get the flow rate of saliva. Salivary pH is measured using a pH meter while reducing sugar levels are measured using the Benedict's test. The sample for this study consisted of 50 Ukrida FK students. The results of this study indicate that the highest salivary flow rate is after chewing xylitol chewing gum. While the reducing sugar levels in saliva are only found after chewing sucrose chewing gum. For salivary pH values, after chewing sucrose chewing gum the most acidic pH was obtained when compared to after chewing paraffin and xylitol chewing gum. From the research that has been done, after consuming paraffin, xylitol chewing gum and sucrose chewing gum, the highest salivary flow rate was obtained after consuming xylitol chewing gum, while the lowest was after consuming paraffin. Meanwhile, the highest pH value of saliva was after consuming paraffin and the lowest was after consuming sucrose chewing gum. Meanwhile, reducing sugar levels in saliva was only found after consuming sucrose chewing gum and was not found after consuming paraffin and xylitol chewing gum. From this study it can be concluded that there are differences in the characteristics of saliva among FK Ukrida students after consuming paraffin, xylitol chewing gum and sucrose chewing gum.

scholarly journals Application Of Seeding Crystallization as a Pre-Treatment Stage for The Reduction of Scaling Tendency of Seawater Feed to Thermal Desalination Units

2021 ◽  
Vol 15 (1) ◽  
pp. 10-17
Author(s):  
Mazen N. Al-Amaireh
Keyword(s):  
Kinetic Parameters ◽  
Growth Kinetic ◽  
Growth Process ◽  
Ph Value ◽  
Operating Conditions ◽  
Integration Step ◽  
Surface Integration ◽  
Thermal Desalination ◽  
Initial Ph ◽  
Pre Treatment

Objective: The fouling inhibition in seawater desalination and scale control using crystallization with calcite seeds is evaluated experimentally in this study. Methods: The growth kinetic parameters are determined experimentally, correlated and discussed at different operating conditions. Supersaturation levels represent driving force behind the growth of crystals, which is influenced directly by seawater pH values and temperatures. Results: Results indicate that the initial pH value of seawater must be controlled to be in the range (8-9) and calcite seeds will not have the potential to start the growth process in seawater at the normal pH (7.36). The growth kinetic parameters are determined from the measured desupersaturation curves. Conclusion: It is found that the growth process of calcite is controlled by the surface integration step. The growth rate of calcite increases with increasing temperature and seeding ratio (up to 1 g/L), while it decreases with increasing the salinity of seawater.

scholarly journals THE PREFERENTIAL WELD CORROSION OF X65 CARBON STEEL PIPELINE UNDER CO2 ENVIRONMENT

2020 ◽  
Vol 42 (1) ◽  
pp. 15-28
Author(s):  
Nofrizal Nofrizal
Keyword(s):  
Weld Metal ◽  
Flow Rate ◽  
Heat Affected Zone ◽  
Pipeline Steel ◽  
Jet Impingement ◽  
Corrosion Process ◽  
Corrosion Mechanism ◽  
Submerged Jet ◽  
Corrosion Rates ◽  
Weld Corrosion

Preferential weld corrosion (PWC) is a severe corrosion form of attack found in pipeline weldments in oil and gas industries. PWC occurs when the corrosion rate of the weld metal (WM) and heat affected zone (HAZ) is higher than the parent metal (PM). PWC was generated by galvanic corrosion mechanism due to dissimilarities in the composition and microstructure of the metal in the three weld regions.The aim of this research is to study the effect of flow rate on preferential weld corrosion (PWC) in X65 high strength pipeline steel using submerged jet impingement by investigating the mechanism of PWC on a weldment in artificial seawater saturated with carbon dioxide at 1 bar. A novel submerged jet impingement apparatus that consist of 3 rings (outer, inner and centre) was designed so that the parent material, heat affected zone and weld metal could be analysed in a high shear stress environment. Corrosion experiments were performed with X65 pipeline steel under no flow and flowing condition at 10 m/s at 30oC and pH4. The galvanic current characteristic between the weldment regions was recorded using a zero-resistance ammeter, and the self-corrosion was analysed by using linear polarisation resistance measurements. Total corrosion rates were calculated from the sum of the galvanic and self-corrosion contributions. The morphology, structure, chemical on the surface of X65 after corrosion process was investigated by means of scanning electron microscopy (SEM) and focus ion beam (FIB) to examine the corrosion product that form in brine containing dissolved carbon dioxide.In a no-flow condition, the result shows that the galvanic characteristics on all weldments were similar and the WM is cathodic and protected in comparison with the HAZ and PM. In flowing condition, the estimated flow rates associated with the different positions on the target vary depending on either (a) PM and HAZ or (b) the WM. The effects of target flow rate on WM have a similar trend, but the overall corrosion rates are greater due to PWC. The result of surface analysis after corrosion process showing that removal of hardened layer and subsurface cracking were causes of enhanced degradation.

scholarly journals Optimization of Ammonia Stripping of Piggery Biogas Slurry by Response Surface Methodology

2019 ◽  
Vol 16 (20) ◽  
pp. 3819 ◽  
Author(s):  
Mengyuan Zou ◽  
Hongmin Dong ◽  
Zhiping Zhu ◽  
Yuanhang Zhan
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Flow Rate ◽  
Gas Flow ◽  
Ph Value ◽  
Removal Rate ◽  
Ammonia Nitrogen ◽  
Biogas Slurry ◽  
Gas Flow Rate ◽  
Ammonia Stripping

Ammonia stripping is a pretreatment method for piggery biogas slurry, and the effectiveness of the method is affected by many factors. Based on the results of single-factor experiments, response surface methodology is adopted to establish a quadratic polynomial mathematical model relating stripping time, pH value and gas flow rate to the average removal rate of ammonia nitrogen to explore the interactions among various influencing factors, obtain optimized combined parameters for ammonia stripping, and carry out experimental verification of the parameters. The results show that when hollow polyhedral packing is adopted under operating conditions including a stripping time of 90 min, pH value of 11, gas flow rate of 28 m3/h, gas–liquid ratio of 2000 and temperature of 30 °C, the average removal rate of ammonia nitrogen in biogas slurry can reach approximately 73%. The experimental value is only 4.2% different from the predicted value, which indicates that analysis on the interaction among factors influencing ammonia stripping of biogas slurry and parameter optimization of the regression model are accurate and effective.

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