scholarly journals Experimental Study on Erosion–Corrosion of TP140 Casing Steel and 13Cr Tubing Steel in Gas–Solid and Liquid–Solid Jet Flows Containing 2 wt % NaCl

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 358 ◽  
Author(s):  
Jiarui Cheng ◽  
Zhen Li ◽  
Ningsheng Zhang ◽  
Yihua Dou ◽  
Lu Cui
Keyword(s):  
Flow Velocity ◽  
Erosion Rate ◽  
Electrode System ◽  
Jet Flows ◽  
Uniform Corrosion ◽  
Two Phase ◽  
Erosion Rates ◽  
Erosion Corrosion ◽  
Two Parameters ◽  
Impact Angles

To study the erosion–corrosion characteristics of TP140 casing steel and 13Cr tubing steel in oil fields, we performed gas–solid and liquid–solid jet flow experiments to control particle addition, jet angle, and flow velocity and measure erosion and corrosion components. Meanwhile, we used a standard three-electrode system to study the changes in electrochemical parameters on a metal surface in a two-phase flow containing 2 wt % NaCl. Results showed that erosion is mainly dominated by the flow velocities and impact angles of particles, and corrosion rate is mainly affected by liquid flow rate. The erosion rates of the two materials increase with flow velocity, and the critical angle of maximum erosion rate exists. Meanwhile, flow velocity growth increases the current density on the TP140 surface while reducing the corrosion potential of 13Cr, but the effect of the angle on the two parameters is relatively small. The uniform corrosion of TP140 increases the erosion rate in the range of 10–20%, and the pitting of 13Cr increases the erosion rate in the range of 30–90%, indicating that the interaction between the erosion and corrosion of stainless steel is obvious.

Effects of Erosion Rate on the Erosion-Corrosion Synergism of High Velocity Oxy-Fuel Sprayed Ni-Based Coatings

2008 ◽  
Vol 373-374 ◽  
pp. 585-588 ◽  
Author(s):  
An Feng Zhang ◽  
Yu Yue Wang ◽  
Chang Jiu Li
Keyword(s):  
High Velocity ◽  
Erosion Rate ◽  
Steel Substrate ◽  
Silica Sand ◽  
Volume Loss ◽  
Low Carbon ◽  
Hvof Spraying ◽  
Two Phase ◽  
Erosion Corrosion ◽  
Loss Rates

Two types of Ni-based coatings were deposited by high velocity oxy-fuel (HVOF) spraying process on ASTM 1020 low carbon steel substrate, and AISI 321 stainless steel was applied to the contrast test. The influences of erosion rate on the erosion-corrosion synergism and erosion-wear mechanism of the two coatings were investigated systematically in a liquid/solid two-phase flow (5% H2SO4 +15% silica sand). The volume loss rates stemming from the erosion-corrosion synergism of materials increased from 42~66% to 78~85% of the total volume loss rates when the erosion rate of the flow increased from 5 m/s to 10 m/s. It was indicated that the erosion-corrosion synergism was primary for the material removing during the erosion-corrosion process. Cutting, wear and plowing were the main features for Type-A coatings, while cutting, plowing and plastic deformation were the main characters for Type-B coatings and the two steels.

scholarly journals Analysis of air jet Erosion on Duplex Stainless Steel

2019 ◽  
Vol 9 (2S2) ◽  
pp. 164-166
Keyword(s):  
Stainless Steel ◽  
Flow Velocity ◽  
Duplex Stainless Steel ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Erosion Rate ◽  
Effective Control ◽  
Air Jet ◽  
Impact Angles

The prevention or minimization of erosion is an urgent need. The proper selection of the material and the adopting methods for controlling the factors influencing erosion are the commonly used techniques. Duplex Stainless Steel because of its good corrosion resistance and other properties becomes a common choice. To have an effective control over erosion we must understand the effect of each parameter over the rate of erosion. Air jet test rig was used to study the erosion behavior of Duplex Stainless steel of 2205 grade in a controlled environment. Erosion tests were carried out with varying angle of impact, flow velocity and mass flow rate under standard conditions using an air jet erosion rig made according to ASTM G76 standard. Examination of the results associated with various elements such as impact angles, mass flow rate and flow velocity. The results showed that the erosion rate was maximum at lower impact angles and decreases with higher impact angles and the erosion rate increase with an increase in velocity and decrease with the increase in mass flow rate

Gas–Solid Erosion Wear Characteristics of Elbow Pipe With Corrosion Defects

2021 ◽  
Vol 143 (5) ◽  
Author(s):  
Jie Zhang ◽  
Hao Zhang ◽  
Xiaohua Chen ◽  
Chunyu Yu
Keyword(s):  
Flow Rate ◽  
Erosion Rate ◽  
Structural Parameters ◽  
Uniform Corrosion ◽  
Erosion Wear ◽  
Wear Characteristics ◽  
Corrosion Defect ◽  
Erosion Rates ◽  
Erosion Area ◽  
Corrosion Defects

Abstract Corrosion and erosion are the main factors of pipes failure. Erosion wear characteristics of elbow pipe with corrosion defect are investigated in this paper. Initially, the erosion result of nondefect elbow pipe is calculated and compared to elbow pipe with corrosion defect. An elliptical erosion area with a V-shaped dent occurs at the extrados due to the particles' impact. The uniform corrosion defects change the structure of the pipe's inner surface. Therefore, the defect areas are more prone to be impacted by particles and then more severe erosion occurs. The maximum erosion rates of corrosion defect and noncorrosion area synchronously reach the maximum value as the corrosion defect located at 55 deg. The larger the particle mass flow rate is, the more severe the elbow pipe erosion is. As the flow rate increases, erosion rates of corrosion area and noncorrosion area increase, while the maximum erosion rate of corrosion area occurs at 55 deg. Structural parameters of corrosion defects affect the erosion. As the distance between two corrosion defects increases, the maximum erosion rate of lower corrosion defect increases. Considering the location, structure, and number of corrosion defect, a larger corrosion defect located in the middle of extrados has a worse effect on elbow pipe safety.

scholarly journals Impacts of oak deforestation and rainfed cultivation on soil redistribution processes across hillslopes using 137Cs techniques

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shamsollah Ayoubi ◽  
Nafiseh Sadeghi ◽  
Farideh Abbaszadeh Afshar ◽  
Mohammad Reza Abdi ◽  
Mojtaba Zeraatpisheh ◽  
...  
Keyword(s):  
Land Use ◽  
Magnetic Susceptibility ◽  
Soil Erosion ◽  
Erosion Rate ◽  
Land Use Changes ◽  
Soil Samples ◽  
Natural Forest ◽  
Oak Forests ◽  
Erosion Rates ◽  
Rainfed Farming

Abstract Background As one of the main components of land-use change, deforestation is considered the greatest threat to global environmental diversity with possible irreversible environmental consequences. Specifically, one example could be the impacts of land-use changes from oak forests into agricultural ecosystems, which may have detrimental impacts on soil mobilization across hillslopes. However, to date, scarce studies are assessing these impacts at different slope positions and soil depths, shedding light on key geomorphological processes. Methods In this research, the Caesium-137 (137Cs) technique was applied to evaluate soil redistribution and soil erosion rates due to the effects of these above-mentioned land-use changes. To achieve this goal, we select a representative area in the Lordegan district, central Iran. 137Cs depth distribution profiles were established in four different hillslope positions after converting natural oak forests to rainfed farming. In each hillslope, soil samples from three depths (0–10, 10–20, and 20–50 cm) and in four different slope positions (summit, shoulder, backslope, and footslope) were taken in three transects of about 20 m away from each other. The activity of 137Cs was determined in all the soil samples (72 soil samples) by a gamma spectrometer. In addition, some physicochemical properties and the magnetic susceptibility (MS) of soil samples were measured. Results Erosion rates reached 51.1 t·ha− 1·yr− 1 in rainfed farming, whereas in the natural forest, the erosion rate was 9.3 t·ha− 1·yr− 1. Magnetic susceptibility was considerably lower in the cultivated land (χhf = 43.5 × 10− 8 m3·kg− 1) than in the natural forest (χhf = 55.1 × 10− 8 m3·kg− 1). The lower soil erosion rate in the natural forest land indicated significantly higher MS in all landform positions except at the summit one, compared to that in the rainfed farming land. The shoulder and summit positions were the most erodible hillslope positions in the natural forest and rainfed farming, respectively. Conclusions We concluded that land-use change and hillslope positions played a key role in eroding the surface soils in this area. Moreover, land management can influence soil erosion intensity and may both mitigate and amplify soil loss.

Numerical Study on the Erosion Characteristics of U-Type Bend for Gas Solid Flow

2017 ◽  
Author(s):  
Yu Wang ◽  
Qi He ◽  
Ming Liu ◽  
Weixiong Chen ◽  
Junjie Yan
Keyword(s):  
Particle Size ◽  
Erosion Rate ◽  
Loading Rate ◽  
Pipe Wall ◽  
Numerical Study ◽  
Pulverized Coal ◽  
Mass Loading ◽  
Two Phase ◽  
Inlet Velocity ◽  
Pipe System

In pulverized coal-fired plant, the U-type bend is commonly used in flue gas and pulverized coal pipe system to due to the constraints of outer space. And gas-solid two-phase flow exists in these pipelines. The erosion of the pipe has significant effect on the safety and reliability of pipelines. In present paper, the erosion characteristics of U-type bend were investigated through CFD (Computational Fluid Dynamics) method. The wear distribution on the pipe wall was obtained. And the particle flow characteristics in U-type bend were analyzed. The influence of inlet velocity, mass loading rate and particle size on the erosion rate was studied as well. Result suggested that the maximum erosion rate increases exponentially with the increase of inlet velocity. And maximum erosion rate increases linearly with the increasing mass loading rate. Increasing particle size can aggravate the wear on the pipe wall.

scholarly journals Coupling Analysis of Fluid-Structure Interaction and Flow Erosion of Gas-Solid Flow in Elbow Pipe

2014 ◽  
Vol 6 ◽  
pp. 815945 ◽  
Author(s):  
Hongjun Zhu ◽  
Hongnan Zhao ◽  
Qian Pan ◽  
Xue Li
Keyword(s):  
Erosion Rate ◽  
Structural Changes ◽  
Fluid Structure Interaction ◽  
Fluid Phase ◽  
Diameter Ratio ◽  
Pipe Diameter ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Fluid Structure ◽  
Structure Interaction

A numerical simulation has been conducted to investigate flow erosion and pipe deformation of elbow in gas-solid two-phase flow. The motion of the continuous fluid phase is captured based on calculating three-dimensional Reynolds-averaged-Navier-Stokes (RANS) equations, while the kinematics and trajectory of the discrete particles are evaluated by discrete phase model (DPM), and a fluid-structure interaction (FSI) computational model is adopted to calculate the pipe deformation. The effects of inlet velocity, pipe diameter, and the ratio of curvature and diameter on flow feature, erosion rate, and deformation of elbow are analyzed based on a series of numerical simulations. The numerical results show that flow field, erosion rate, and deformation of elbow are all sensitive to the structural changes and inlet condition changes. Higher inlet rate, smaller curvature diameter ratio, or smaller pipe diameter leads to greater deformation, while slower inlet rate, larger curvature diameter ratio, and larger pipe diameter can weaken flow erosion.

scholarly journals Assessment of Soil Erosion Vulnerability in the Heavily Populated and Ecologically Fragile Communities in Motozintla De Mendoza, Chiapas, Mexico

2017 ◽  
Author(s):  
Selene B. González-Morales ◽  
Alex Mayer ◽  
Neptalí Ramírez-Marcial
Keyword(s):  
Soil Erosion ◽  
Erosion Rate ◽  
Negative Response ◽  
Attitudes And Practices ◽  
Erosion Rates ◽  
Soil Erosion Rate ◽  
Kap Survey ◽  
Level Of Knowledge ◽  
Steep Slopes ◽  
Knowledge Attitudes And Practices

Abstract. The physical aspects and knowledge of soil erosion in six communities in rural Chiapas, Mexico were assessed. Average erosion rates estimated with the RUSLE model ranged from 200 to 1,200 ha−1 yr−1. Most erosion rates are relatively high due to steep slopes, sandy soils and bare land cover. The lowest rates occur where corn is cultivated for much of the year and slopes are relatively low. The results of a knowledge, attitudes and practices (KAP) survey showed that two-thirds of respondents believed that the major cause of soil erosion was hurricanes or rainfall and only 14 % of respondents identified human activities as causes of erosion. Forty-two percent of respondents indicated that the responsibility for solving soil erosion problems lies with government, as opposed to 26 % indicating that the community is responsible. More than half of respondents believed that reforestation is a viable option for reducing soil erosion, but only a third of respondents were currently applying reforestation practices and another one-third indicated that they were not following any conservation practices. The KAP results were used to assess the overall level of knowledge and interest in soil erosion problems and their solutions by compiling negative responses. The community of Barrio Vicente Guerrero may be most vulnerable to soil erosion, since it had the highest average negative response and the second highest soil erosion rate. However, Poblado Cambil had the highest estimated soil erosion rate and a relatively low average negative response rate, suggesting that soil conservation efforts should be prioritized for this community. We conclude that as long as the economic and productive needs of the communities are not solved simultaneously, the risk of soil erosion will increase in the future, which threatens the survival of these communities.

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