Erosion Corrosion Behavior Research Articles

A study on the erosion-corrosion behaviour of engineering materials used in the geothermal industry

Erosion-corrosion can be a significant issue for engineering components used in the geothermal industry. This study assesses the erosion-corrosion behaviour of a wide range of engineering alloys which are used in various parts of geothermal power plants. The evaluated materials comprised a carbon steel, low-alloy steel, three grades of stainless steel together with Ni–Cr alloy (Inconel 625) and Ti–6Al–4V. Tests were conducted by utilising a submerged 90° impinging slurry jet consisting of silica sand particles suspended in an acidic (pH 4) aqueous solution consisting of 3.5% NaCl. Gravimetric mass losses, in-situ potentiodynamic polarisation scans and an enhanced volumetric analysis technique were used to assess the influence of hydrodynamic conditions on the erosion-corrosion behaviour of the test materials. The effect of applied cathodic protection was also examined. Post-test metallurgical examination was also conducted via SEM. The results showed the distinct differences between low alloy steels and “corrosion resistant” alloys – with the former demonstrating substantial material loss in the low-angle corrosive wear region due to large amounts of corrosion-related damage. Both superaustenitic stainless steel (UNS S31254) and Inconel 625 (UNS N06625) exhibited the greatest erosion-corrosion resistance of the test materials – with Inconel 625 demonstrating the greatest resistance to high angle corrosive wear. The relevance of the findings to materials selection and other methods of protection against surface degradation in geothermal power plants is discussed.

Erosion-corrosion behaviour of steels used in slurry pipelines

The regular replacement and maintenance of steel pipes used to transport the slurry processed in oil sands mining and extraction represent a major expense for oil sands operations. Erosion-corrosion tests reveal that the performance of the steels is strongly influenced by the slurry velocity, which affects the severity of the erosion-corrosion synergy. In this study, the erosion-corrosion behavior of API 5L X65, X70, and X80 steels was assessed at two different slurry velocities (3.5 and 5 m/s) and two different aeration levels or dissolved oxygen (DO) levels (0.6 and 3.8 ppm). Results of the tests were compared to those of an ASTM A1053 Gr.50 dual-phase (DP) stainless steel and AR400 hard plate. The tests were performed at 60 °C in sand-containing slurry (20% vol. silica) with 500 ppm chloride, which replicated common field conditions. Characterization of the steels was carried out with optical and scanning electron microscopy, energy dispersive x-ray spectrometry, x-ray diffraction technique, micro-mechanical probe, and electrochemical testing. The results showed that at the DO level of 3.8 ppm, the DP stainless steel featured the highest erosion-corrosion resistance at the slurry velocity of 3.5 m/s, while its performance was inferior to that of the carbon steels as the slurry velocity was increased to 5.5 m/s. At the lower DO level, the DP stainless steel erosion resistance was relatively similar to the carbon steels but deteriorated as slurry velocity was increased. Possible mechanisms responsible for the observed variations in the erosion-corrosion resistance under the testing conditions are analyzed and discussed.

Cavitation erosion-corrosion behaviour of Fe-10Cr martensitic steel microalloyed with Zr in 3.5 % NaCl solution

The corrosion and cavitation erosion-corrosion behaviour of two newly developed Fe-10Cr martensitic steels were investigated in 3.5 % NaCl solution compared with 304 stainless steel. It is found that the passivation ability of the martensitic steel was improved and the corrosion rate was decreased by the addition of Zr. The mass loss test showed that the martensitic steels, especially the steel microalloyed with Zr had better cavitation erosion-corrosion resistance than 304 stainless steel. Further characterisation of the white layer on the damaged surface indicated that the addition of Zr changed the cavitation erosion-corrosion mechanism of the martensitic steel.

Experimental and numerical simulation of erosion-corrosion of 90° steel elbow in shale gas pipeline

Coexistence of the solid particle erosion and acid liquid corrosion is common in shale gas gathering and transportation pipelines. It is conceivable that the synergistic effect of erosion and corrosion accelerates the pipeline damage process. In this research, a novel experimental device is designed to study the erosion-corrosion characteristics of 90° steel elbow in the gas-liquid-solid three-phase flow. A total of 28 group experiments are designed including 4 gas velocities, 3 liquid pH values, and 150 μm average sand particles. Moreover, a numerical simulation model is built based on the FLUENT code to predict the erosion-corrosion behavior. Experimental and simulation results show that the most severe erosion-corrosion region of the pipe bend occurs at the axial angle of the elbow between 20° and 50° and at the radial angle of the elbow between −45° and 45°. At the bottom of the elbow and the outer wall surface close to the outlet, the synergistic effect of erosion and corrosion accelerates the wear of the pipeline, but the opposite phenomenon exists at the position of the elbow with an axial angle of 50–70°.

Optimization of erosion wears of Al–Mg–Si–Cu–SiC composite produced by the PM method

Abstract Metal matrix composites are expanding their range every day due to their various industrial applications in manufacturing sectors, to attain high performance and favorable characteristics such as light weight, more excellent corrosion as well as wear resistance, high specific strength and high temperature-resistance than conventional materials. This study deals with analysis on erosion wear characteristic and corrosion behavior of newly-engineered aluminum metal–matrix composite (Al–0.5Si–0.5Mg–2.5Cu–5SiC) developed by powder metallurgy method. Solid particle erosion test was conducted on the newly developed AMMC product and the execution of design of experiments through Taguchi and statistical techniques demonstrates the feasibility of investigating the erosion characterization and behaviors of the composites. Sixteen set of experimental trials were performed by considering three process parameters (impact angle, stand-off distance, and impact velocity) associated with four levels each. Experimental results in accordance of Taguchi’s orthogonal array design of experiments are analyzed by employing analysis of variance (ANOVA), response surface methodology (RSM) and desirability function approach for analysis, predictive modeling and optimization of erosion rate, respectively. Thereafter, an observation on eroded surface morphology is performed under the influence of impact velocity by employing scanning electron microscope (SEM) to entrench the process. Result shows that, the impact velocity followed by impact angle have significant contribution (80.42 and 8.71%, respectively) in improvement of erosion rate. The methodology proposed in this study collects the experimental results and builds a mathematical model in the domain of interest and optimized the process model. Under the highest desirability (1), desirability-function approach of RSM presented the optimal manufacturing conditions at impact velocity of 18 m/s, stand-off distance of 26 mm and impact angle of 67° with estimated erosion rate of 65.155 mg/kg. The experimental data generated for Al–0.5Si–0.5Mg–2.5Cu–5SiC AMMC will be useful for the industry.

Synergistic erosion–corrosion behavior of X80 pipeline steel at various impingement angles in two-phase flow impingement

The purpose of this investigation was to document and understand the erosion corrosion of X80 pipeline steel under different angles of attack in two-phase flow impingement. The erosion corrosion behavior of X80 pipeline steel was studied by using sand jet. The weight loss, surface morphology and electrochemical performance of X80 pipeline steel under different angles of impact (30°, 45°, 60°, 75°, 90°) were studied at 12 m/s flow rate. The synergistic mechanism of erosion corrosion of X80 pipeline steel under different environment was analyzed. The experimental results show that the weight loss of the sample in pure water increased with the decrease of the impact angle. The weight loss of the sample in the sodium chloride solution decreased first and then increased with the decrease of the impact angle, reaching a minimal value at 60° impact angle. Positive synergy was observed at all impact angles, and synergy was most significant when the impact angle was 90°. The samples impacted at 30° showed the best corrosion resistance by electrochemical measurement. The corrosion resistance of the sample was consistent with the synergistic effect.

Studying the Erosion Corrosion Behavior of NiCrAlY Coating Layer Applied on AISI 446 Stainless Steel Using Thermal Spray Technique

Erosion-Corrosion behavior of NiCrAlY coatings deposited on 446 stainless steel samples by flame thermal spraying was performed in this research. The hardness of uncoated and coated sample is measured, using HVS-1000 Digital Micro hardness Tester. The results of hardness show that the coated samples have higher hardness than uncoated samples. Microstructure and phase analysis of the coating layer was observed by using optical microscope, X-ray diffraction (XRD), and SEM respectively. Erosion –Corrosion test was performed in different period of time (6, 12, and 18 hr.) using the erosion-corrosion system. The result shows that because of uniform distribution and homogeneous of coating layer, weight loss was very low and approximately equal in all period of testing time.

Effect of Alloying Elements on the Erosion–Corrosion Behaviour of Cu-Based Alloys

This study used a powder metallurgy (P/M) to prepare a sample of a Cu / 9.5 % Al alloy and add alloying elements (9.5 % Al five % Ni 0.9 % Mn 4.5 % Fe 0.2 % Ge) to it. The Cu / five % Ni alloy has been used for comparison with other research alloys. The powders were mixed for six hours and pressed under 750 MPa. The samples were sintered at 550 °C for two hours, and then the temperature was raised to 950 °C for a period of 180 min with a heating rate of ten °C / min under an inert gas environment with a continuous stream of argon. It was then left to cool inside the furnace. After this, several heat treatments were used. Some tests were carried out, such the scanning electron microscopy (SEM), energy dispersion spectrometer (EDS), X-ray diffraction (XRD), Vickers micro-hardness and the erosion–corrosion test. The alloy Cu / five % Ni showed the least hardness. The addition of Ni, Mn and Fe to the Cu / 9.5 % Al alloy increased the hardness, and these additions caused a relative increase in the resistance to erosion–corrosion. However, it also caused a large increase in the resistance to erosion–corrosion when adding Ge to the alloy Cu / 9.5 % Al / five % Ni 0.9 % Mn 4.5 % Fe 0.2 % Ge when immersed in seawater. Additionally, it demonstrates a high hardness. These improvements were attributed to an enhancement of the properties of alloy-based Cu – 9.5 % Al, which is used in the marine industry.

Erosion-Corrosion Behavior and Mechanism of Heated Electroless Ni–P Coating under Flow

Erosion-Corrosion Behavior and Mechanism of Heated Electroless Ni–P Coating under Flow

Synergistic Erosion-Corrosion Behavior of AISI 2205 Duplex Stainless Steel Elbows in Potash Brine-Sand Slurry and the Associated Microstructural Changes

Slurry erosion-corrosion damage to materials used in mineral processing industries occurs due to the combined effects of electrochemical and mechanical processes. In this study, AISI 2205 duplex stainless steel elbows were tested in a flow loop using slurries consisting 10, 20, 30, 40 and 50 wt.% sand particles and saturated potash brine. Erosion-corrosion tests were conducted at flow velocities of 2.5 and 4.0 m/s. The results of the gravimetric analysis revealed that erosion-corrosion rates increased with increasing particle concentration at both velocities. The elbows exhibited negative synergy for all operating conditions, which is attributed to the presence of passive oxide film on the surface. Microstructural examination of the eroded surfaces showed that materials removal occurred by cutting and plastic deformation. Electron backscattered diffraction analysis suggests that plastic deformation, which occurred approximately 4 µm below the eroded surface, led to the transformation of metastable austenite phase to martensite.

Simulation Analysis of Erosion–Corrosion Behaviors of Elbow under Gas-Solid Two-Phase Flow Conditions

In the production and gathering process of coal gas, the complex composition of the coal gas, harsh environments, the complex medium, and high content of solid particles in slurry cause the equipment malfunctions and even failure because of erosion and corrosion. In the present study, COMSOL multi-physics finite element simulation software is used to simulate the erosion–corrosion behaviors of elbow in key chemical equipments. The electrochemical corrosion, solid particle erosion, chemical reaction, and turbulent flow are coupled together. The particle count method is proposed to clarify the erosion phenomenon. The simulation results show that particles with high turbulent intensity hit the wall of elbow directly, which forms a slanted elliptical erosion zone on the extrados surface at 40°–50°. The chemical reaction in turbulence has a difference in the concentration distribution of substances, and this phenomenon leads to different magnitudes of the corrosion current densities in the tube. Moreover, 1/6 released particles hit the extrados surface of the elbow. These findings are beneficial to understand the erosion–corrosion phenomena and design the elbow in key chemical equipment.

Effect of Oxide Film on the Cavitation Erosion-Corrosion Behavior of Nickel-Aluminum Bronze Alloy

The effect of oxide film on the cavitation erosion-corrosion of nickel-aluminum bronze (NAB) alloy in 3.5 wt% NaCl solution was investigated via pulse and continuous cavitation modes of ultrasonic vibrator device according to ASTM. NaCl solution was used to simulate the seawater condition of NAB alloy. In the same effective cavitation erosion time of 8 h, the total mass loss caused by continuous cavitation erosion-corrosion was 21.45±0.75 mg, which was almost 1.5 times as much as that of pulse mode. The synergistic effect of cavitation erosion and corrosion was analyzed. The results showed that the total contribution of the synergy component in the process of continuous cavitation erosion-corrosion was 51.66%, while it fell to 25.56% in the pulse mode. The open-circuit potential measurements and electrochemical atomic force microscope test demonstrated that the rapid repair of an oxide film during pulse cavitation played an important role in resisting the cavitation erosion-corrosion. Furthermore, the formation process of oxide film was in situ observed, indicating higher nucleation rate compared with its growth rate. Also, the alloy with such film exhibited lower synergy in pulse mode than that without film in continuous mode.

Erosion corrosion behaviour and mechanical properties of wire arc sprayed Ni-Cr and Ni-Al coating on boiler steels in a real boiler environment

ABSTRACT The aim of the current investigation is to evaluate the erosion-corrosion (E-C) performance of wire arc sprayed Ni-20Cr and Ni-5Al coatings on T22 and SA516 boiler steels in a real boiler environment. The microstructure, mechanical properties and high temperature E-C performance of the deposited coatings were investigated. The E-C behaviour of the test samples was determined in the superheater zone of the coal fired boiler at 750°C for fifteen cycles, where each cycle involved 100 hours of heating followed by 1hour of cooling. Thickness loss data was used to determine the E-C behaviour of the coating. XRD, SEM/EDS were used to analyse the test samples. Ni-20Cr coated SA516 steel decreased maximum E-C rates by 98.05%, while Ni-5Al coated T22 steel reduced E-C by 68.63% than the base steel. This higher E-C resistance is due to the formation of protective phases (Cr2O3, NiO and Al2O3) and better mechanical properties of the coatings.

Thermal Spray Coatings for Erosion–Corrosion Resistant Applications

Thermal spray techniques have been extensively used to deposit coatings of varying compositions on a variety of industrial components for life enhancement under wear and corrosion prone environments at ambient and high temperatures. A number of components used in power generation systems most commonly encounter high-temperature erosion–corrosion. This review article briefly summarizes various thermal spray techniques and coating characteristics that are relevant to erosion–corrosion applications followed by detailed discussion on the erosion–corrosion fundamentals and testing methods. Further, ambient and high-temperature erosion–corrosion behavior of WC- and CrC-based cermet coatings and oxide coatings have been investigated, compared, analyzed and presented. Based on the analysis of results reported so far, the methodologies to enhance the erosion–corrosion resistance of coatings have been proposed both for ambient and high temperature applications. The future scope of work that needs to be explored to contribute further developments has also been identified and presented.

Erosion–Corrosion of AISI 304L Stainless Steel Affected by Industrial Copper Tailings

A comprehensive analysis of the erosion–corrosion behavior of AISI 304L stainless steel immersed in 0.5 M NaCl solution with the addition of industrial tailing particles obtained from the copper mining industry is reported. From fundamental studies using combined measurements of potentiodynamic and weight loss techniques, the pure corrosion, pure erosion, and their synergism on the total wear rate were evaluated. The results showed that the presence of soluble chemical reagents dragged by tailing particles significantly affects the pure corrosion rate in comparison with a NaCl solution without these chemical reagents. In addition, the wear of stainless steel by pure erosion was found to be more important than that of pure corrosion. Erosion–corrosion tests performed under an open circuit potential behavior indicate lower and higher wear values than that obtained for erosion and corrosion rates, respectively. Through these results, it was possible to determine an antagonistic effect for AISI 304L stainless steel in industrial tailings slurries. These results are supported by changes in the electrochemical parameters, passive film stability, and morphological attributes.

Effects of flow velocity and impact angle on erosion-corrosion of an API-5 L X65 steel coated by plasma nitriding of hard chromium underlayer

In this study, the erosion-corrosion behavior of an API-5L-X65 steel coated by plasma nitriding of hard chromium underlayer has been investigated as a function of flow velocity (4, 5, 6, 7.5m s−1) and impact angle (30°, 45°, 60°, 90°) by a slurry of 3.5wt.% NaCl, and 3wt.%SiO2. The structure and microstructure of coating were characterized by X-ray diffractometry and scanning electron microscopy techniques. The maximum of mass loss was at the impact angle of 45° which the degradation slightly decreased with the increase of impact angle. However, the maximum degradation of the CrN coated samples occurred at normal impact angle. The analysis of erosion-corrosion mechanism showed the erosion process was more effective than corrosion.

Erosion Corrosion Behavior of Aluminum Electrode in Simulated HVDC Water Cooling at 50 °C

Erosion Corrosion Behavior of Aluminum Electrode in Simulated HVDC Water Cooling at 50 °C

Influence of Sand Fines Transport Velocity on Erosion-Corrosion Phenomena of Carbon Steel 90-Degree Elbow

Erosion-corrosion is an ineluctable flow assurance problem confronted in hydrocarbon transportation and production systems. In this work, the effect of sand fines velocity on the erosion-corrosion behavior of AISI 1018 carbon steel long radius 90° elbows was experimentally and numerically investigated for liquid-solid flow conditions. Experiments were effectuated for sand fines of mean diameter 50 µm circulated in a flow loop with three different velocities (0.5, 1 and 2 m/s). To elucidate the erosion-corrosion mechanism and degradation rate, the material loss analysis, multilayer paint modeling (MPM) and microscopic imaging technique were employed, with computational fluid dynamics (CFD) and discrete phase modeling (DPM) also capacitating to evaluate the erosion distribution. It was perceived that increasing slurry velocity significantly changes the particle-wall impaction mechanism, leading to an increase in material degradation in the elbow bottom section up to 2 times in comparison to the low transport velocity. The erosion scars and pits development at the elbows internal surface was found to govern the wear mechanism in the carbon steel and made downstream section susceptible to erosion and corrosion. The material removal mechanisms were ascertained to change from cutting to pitting and plastic deformation with an increase of sand fines transportation velocity from 0.5 m/s to 2 m/s.

Cavitation Erosion-Corrosion Behavior of Fe-Cr Steel Induced by Ultrasonic Vibration

A resistance of cavitation erosion-corrosion of the AISI 420 martensitic stainless steel was evaluated in this study. The cavitation resistance of this stainless steel has been examined using an ultrasonic vibratory method by applying water-voltage combination effect. The curves of cumulative material loss and erosion rate were attained and discussed. In addition, surface topography and scanning electron microscope (SEM) micrographs have been utilized to characterize the eroded surface after the cavitation test. The results have been compared with previously obtained results for the AISI 1040 steel. The cavitation results showed that the AISI 420 steel has exhibited the better resistance to cavitation comparing with the AISI 1040 steel under the similar test conditions. The total cumulative material loss of the AISI 420 was approximately three times less than that of the AISI 1040. Surface topography and SEM micrographs showed that the severity of damage of the AISI 1040 was found to be a higher compared to that of the AISI 420 steel.

Strain uniformity footprint on mechanical performance and erosion-corrosion behavior of equal channel angular pressed pure titanium

In this paper, the effect of equal channel angular pressing (ECAP) on microstructure, mechanical, and erosion-corrosion behavior of commercial pure (CP) titanium was investigated through experimental work. Four passes of ECAP processing at 400 ℃ was performed on CP titanium. The results showed that the homogeneous structure and coarse equiaxed grains of the initial annealed sample are transformed into the combination of UFG and NS with an average size of 750 nm and 85 nm, respectively. Also, ECAP pass numbers increase the fraction of high angle grain boundaries which improves the ductility of the processed sample. The highest hardness and strength improvement rate was observed after the first pass. Furthermore, the increasing rate of hardness and strength is gradually decreased at the subsequent passes and reached the steady-state level at the 4th pass. This is due to the balance between hardening by dislocations and twinnings accumulation and softening by recovery mechanisms. As a result, a uniform hardness distribution on both the cross-sectional and longitudinal planes is achieved. It was confirmed that erosion-corrosion resistance of the processed sample is enhanced due to the grain refinement, material homogeneity, and quick formation of a strong oxide bond layer on the surface.