Material Loss Rate Research Articles

Assessing the tribo-corrosion resistance of surface nanostructured stainless-steel

In this work, surface mechanical rolling treatment (SMRT) was applied as a post-process nanostructuring technique to improve the tribo-corrosion degradation resistance of coarse grain (CG) 316L stainless steel (SS). The experimental findings reveal that when tribo-corrosion wear took place, the CG specimen experienced severe surface de-passivation, which increased wear-corrosion synergy and the rate of material loss. On the other hand, the SMRT specimen experienced enhanced re-passivation kinetics, which reduced wear-corrosion synergy and the rate of material loss. The wear mechanism for both the CG and SMRT specimens was abrasion-dominant, with the CG specimen having the presence of micro-pits within the wear track. In addition to these findings, the reduced surface roughness, improved hardness, formed compressive stresses, microstructural refinement, and martensite phase transformation induced by the SMRT process contributed to the enhanced tribo-corrosion resistance of the SMRT specimen. In total, SMRT was found to be a feasible technique to improve the tribo-corrosion resistance of CG 316L SS.

Process optimization of acq-polyacrylate modified bamboo aggregate and durability analysis of all-bamboo aggregate concrete

All-Bamboo Aggregate Concrete (BAC) is a type of cement concrete material where all coarse aggregates are made of bamboo aggregate, a plant material that requires necessary measures to avoid or slow down its degradation in alkaline and natural environments. This paper enhances the durability of BAC materials through the treatment of bamboo aggregate with ACQ-polyacrylate (AP method). Initially, the study explores the impact of polyacrylate dilution concentration on the compressive strength and coating thickness of BAC, and based on a reasonable modification process, conducts freeze-thaw cycles, salt solution immersion, accelerated wet-dry aging, and long-term natural environment tests to assess the durability of BAC materials. The results show that a polyacrylate solution with a dilution ratio of 1:5 can form a coating thickness of 23.8μm, performing better in various durability evaluations. After 25 freeze-thaw cycles, the BAC material's loss rate of compressive strength is lower than that of Ordinary Concrete (OC). Compared with OC, BAC materials are more susceptible to salt damage after salt solution immersion. The compressive strength loss rate under 180 days of natural environment exposure is comparable to that in 10 cycles of accelerated wet-dry aging, 28 days of salt solution immersion, and 10–15 freeze-thaw cycle tests, recommending the use of freeze-thaw cycle tests for evaluating the durability of BAC materials from an experimental efficiency perspective. By exploring the durability of BAC materials, this paper provides an innovative solution in the field of construction materials, promoting the transition of the construction industry towards sustainable development. It emphasizes the feasibility and effectiveness of improving the performance of bamboo-based materials through surface treatment technology, offering a valid reference for developing more environmentally friendly and high-performance new materials in the future.

Comparative study of special iron-silicon-chromium alloy electrode (FeSiCr) and Zinc electrode (Zn)

Corrosion is an oxidation-reduction reaction that occurs mainly in metals in contact and with different potential energies, both subjected to an environment conducive to the circulation of electrons or ions. A widely used method for protecting metals is cathodic protection, which can be galvanic cathodic protection or impressed current cathodic protection. The structure to be protected by cathodic protection is called the cathode and the other metal that will suffer the sacrifice of donating electrons and being worn out is the anode, normally called the sacrificial anode. There are several types of materials that are used as anodes. Zinc (Zn) is a metal highly recommended as an anode for protecting vessels due to its ease of installation and maintenance. Another material used in cathodic protection as an anode is Iron-Silicon-Chrome (FeSiCr), which is a special alloy, considered inert. Comparing the Zn electrode with the FeSiCr electrode for cathodic protection of buried steel pipes, it can be concluded that the FeSiCr electrode is more efficient. The most relevant factor when comparing the two electrodes in the same condition is their material loss rate.

Some Thoughts on Modeling Abrasion-Corrosion: Wear by Hard Particles in Corrosive Environments

Wear by hard particles can involve abrasion or erosion and is one of the most severe forms of wear. When a corrosive environment is present, the material loss rate can be significantly increased due to interactions (synergy) between the mechanical and chemical/electrochemical actions. In developing strategies for mitigating such adverse synergistic effect, it is important to understand the complex effect of various parameters on material loss under given tribocorrosion conditions. In this paper, a model is presented for wear-corrosion synergy in abrasive wear by hard particles applicable to many conditions in both the marine renewable (abrasion by high concentrations of large sand particles on tidal turbines) and extractive metallurgy (abrasive wear in mineral extraction). The mechanical wear loss is modeled based on the grooving mechanism (micro-cutting/micro-ploughing). Wear-enhanced corrosion is calculated from the fresh surface areas generated by grooving and the corresponding transient corrosion current. The concept of “corrosion-degraded layer” on the worn surface is introduced to account for the corrosion-enhanced wear; within this corrosion-degraded layer, the material loss rate is higher under the same mechanical wear conditions than in the material that is unaffected by corrosion. Based on the model, the effect of wear conditions on synergy in hard particle wear-corrosion has been discussed. The relative thickness of the corrosion-degraded layer to the depth of hard particle penetration (grooving) in the mechanical wear is found to be an important parameter in determining the relative severity of synergy in different tribocorrosion systems. Good qualitative agreement has been observed between the predictions and published experimental results obtained from a range of abrasion-corrosion and erosion-corrosion lab testing.

Assessment of in-vivo corrosion of Ti and CoCrMo joint implants by electrochemical measurements in human synovial liquids

Understanding the corrosion behavior of biomedical materials in the human body is an essential step for the development of improved materials and clinical procedures in arthroplasty. In this work, the corrosion behavior of Ti and CoCrMo alloys in human synovial fluids directly extracted from patients was investigated through an electrochemical experimental protocol, including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The results show that the corrosion behavior of both materials largely depends on patients. The obtained corrosion rates of both materials correspond well to the metal ion release rate detected in patients with joint implants revealing the adequateness of the electrochemical experimental protocol for quantifying in-vivo corrosion of biomedical implants. Based on the results, no significant risk of galvanic corrosion of Ti/CoCrMo coupling is anticipated. The rates of wear-accelerated corrosion (one of the main degradation mechanisms of metallic artificial hip joints) were theoretically extracted from the present electrochemical measurements using an established tribocorrosion model. Those material loss rates are patient-dependent and can be up to two orders of magnitude higher than the static corrosion rates, indicating that the nature of the patient can critically affect the degradation rate of the joint implant.

Measuring flammability of crops, pastures, fruit trees, and weeds: A novel tool to fight wildfires in agricultural landscapes

Fires on agricultural land account for 8–11 % of the total number of fires that occur globally. These fires burn through various crops, pastures, and native vegetation on farms, causing economic and environmental losses. Fire management on farms will be aided by understanding the flammability of plant species as this would allow the design of low-flammability agricultural landscapes, but flammability data on large numbers of agricultural species are lacking. Many crop and vegetable species are assumed to be low in flammability, but this has rarely been tested. Therefore, we examined the shoot and whole-plant flammability of 47 plant taxa commonly grown on farms in Canterbury, New Zealand, which included many globally common temperate agricultural crops. We demonstrated that most of the agricultural species were low to very low in flammability, with many of them (24 taxa; 51 %) not igniting in the experimental burning. Among different crop types, fruit crops and cereals had significantly higher flammability, while taxa categorized as vegetable crops, grazing herbs, pasture grasses, pasture legumes, and weeds were lower in flammability. We further showed that taxa with lower moisture content, higher retention of dead material and faster moisture loss rates were higher in flammability. The strong variation of flammability between the studied taxa suggests that the selection of suitable low flammability species and strategic redesign of agricultural landscapes with fire-retardant planting can be a useful tool to reduce fire hazards and impacts of wildfires in agricultural landscapes.

Low-carbon effects of constructing a prefabricated subway station with temporary internal supports: An innovative case of Shenzhen, China

The traditional cast-in-site (CIS) construction method for subway stations has presented significant challenges to the construction industry in light of the growing labor shortage, prefabricated technology represents a promising alternative. This study introduces a novel prefabricated subway station structure, characterized by the innovative features of "Internal support + Large components + Full assembly." Additionally, the technical processes of the newly designed temporary internal support system for the case station are presented in detail. A greenhouse gas (GHG) emissions quantification model based on construction decomposition is established using the life cycle assessment (LCA) method to assess the low-carbon effect of constructing prefabricated subway stations. Moreover, an integrated project quota GHG emissions inventory is created. The findings demonstrate that the GHG emissions of the full-assembled structure, per unit area, are 6.55% lower than those of the CIS structure, resulting in an emission reduction benefit of 11.21 t CO2e. Notably, structural optimization and reduced material loss rates contribute to an 8.47% decrease in embodied emissions of materials. On average, the GHG emission intensity of the full-assembled station structure during transportation and on-site assembly is higher than that of the CIS structure, amounting to 4.48 t CO2e for a single ring-structure. Regarding GHG emissions during construction, the main structure and the exterior-protected structure of the case station account for 53.62% and 39.24% of the total emissions, respectively. Compared to prefabricated subway station using the temporary anchor cable supporting structure, the temporary internal support system could avoid unnecessary occupation of underground space, which is vital for the sustainable development of underground space in big cities.

Impact-sliding fretting tribocorrosion behavior of 316L stainless steel in solution with different halide concentrations

Impact-sliding caused by random vibrations between tubes and supports can affect the operation of heat exchangers. In addition, a corrosive environment can cause damage, accelerating the synergism of corrosion and wear. Therefore, the focus of this work was the impact-sliding fretting tribocorrosion behavior of 316L heat exchanger tubes at different halide concentrations. A device system incorporating the in situ electrochemical measurements of impact-sliding fretting corrosion wear was constructed, and experiments on 316L heat exchanger tubes in sodium chloride (NaCl) solution with different concentrations (0.0, 0.1, 0.5, 1.0, 3.5, and 5.0 wt%) were carried out. The synergism between wear and corrosion was also calculated and analyzed. The wear and damage mechanisms were elucidated by correlating the corrosion-wear synergism, morphologies, and material loss rates. The results indicated that the stable wear stage occurred at approximately 9–12 h, after which the corrosion current increased with the expansion of the wear area. As the halide concentration increased, the scale of damage on the wear scars gradually decreased, changing from being dominated by cracks, delaminations, and grooves to being dominated by scratches, microgrooves, and holes. There was an obvious positive synergism between wear and corrosion. The material loss was dominated by pure mechanical wear and wear enhanced by corrosion, but corrosion enhanced by wear contributed more than tangential sliding fretting corrosion. The total mass loss increased gradually in the range of 0.0–0.5 wt% and decreased in the range of 0.5–5.0 wt%. Large-scale damage enhanced by corrosivity and small-scale damage reduced by lubricity dominated the material loss at low and high concentrations, respectively.

Correlation Analysis of the Experimental Data for In-Situ Chlorine Generation in Electrochlorination Process

Even though chlorination is a widely used disinfection technique, it has several disadvantages, such as formation of chlorates during prolonged storage, requirement for skilled supervision during operations, risk of leakage, and related accidents during transport and storage. Electrochlorination (EC) is one of the novel technologies generating in-situ chlorine, thereby limiting most of the disadvantages of conventional chlorination treatment for water disinfection. The correlation between the various influencing parameters for EC, which is important for achieving the optimal conditions for in-situ chlorine generation, is still unclear. The major objective of the present study is to provide a detailed correlation analysis between the parameters influencing the EC process based on the extensive experimental data generated from the developed lab-scale setup for electrochlorination using graphite electrodes and titanium electrodes separately. The present study also examined the rate of loss of the electrode materials to check the longevity of electrodes. The experimental results generated were used for comparative analysis of the EC process for maximum in-situ chlorine generation. A detailed principal component analysis (PCA) was performed for the data generated during experimentation to understand the correlation between the influencing parameters for optimum in-situ chlorine generation. The optimum conditions for maximum in-situ chlorine generation obtained from the experiments were 10 V electric voltage, 60 min electrolysis time, 4 cm distance between electrodes, and 3.5 g/L electrolyte concentration, with maximum chlorine generation of 15.95 mg/L obtained for titanium electrodes using NaCl electrolytes for the developed lab setup. The results of PCA established the correlation between the influencing parameters and concluded that the most significant parameter influencing chlorine generation was electrolyte concentration and electrochlorination time, and electric potential was moderately influential, whereas distance between electrodes was least influential. The rate of material loss was 15.3 mg/min for titanium electrodes and 24 mg/min for graphite electrodes, indicating titanium electrodes are more durable than graphite electrodes during a prolonged EC process. The applicability of the generated chlorine stock solution was also examined for drinking water sample disinfection and found to be effective.

Mechanical Structuring of Lithium‐Ion Battery Electrodes Using an Embossing Roller

Highly performing lithium‐ion batteries are essential for the electrification of the transport sector. However, the two performance criteria, high power density and high energy density, inversely correlate with each other via the mass loading of the electrodes. To achieve high charging and discharging rates at high energy densities, structuring of electrodes is a proven method. Currently, structures are mostly realized by laser ablation, which comes along with material loss and low process rates. Herein, a concept for electrode structuring through mechanical embossing in a high‐throughput roll‐to‐roll process is elaborated. Different integration options are described and the challenges are discussed. To provide a proof of concept, a hand‐operated embossing device is built and used to structure graphite anodes. In a rate capability test, an increase in discharge capacity at medium C‐rates by up to 14.3% is observed.

The Effect of a Duplex Surface Treatment on the Corrosion and Tribocorrosion Characteristics of Additively Manufactured Ti-6Al-4V

The use of additively manufactured components specifically utilizing titanium alloys has seen rapid growth particularly in aerospace applications; however, the propensity for retained porosity, high(er) roughness finish, and detrimental tensile surface residual stresses are still a limiting factor curbing its expansion to other sectors such as maritime. The main aim of this investigation is to determine the effect of a duplex treatment, consisting of shot peening (SP) and a coating deposited by physical vapor deposition (PVD), to mitigate these issues and improve the surface characteristics of this material. In this study, the additive manufactured Ti-6Al-4V material was observed to have a tensile and yield strength comparable to its wrought counterpart. It also exhibited good impact performance undergoing mixed mode fracture. It was also observed that the SP and duplex treatments resulted in a 13% and 210% increase in hardness, respectively. Whilst the untreated and SP treated samples exhibited a similar tribocorrosion behavior, the duplex-treated sample exhibited the greatest resistance to corrosion-wear observed by the lack of damage on the surface and the diminished material loss rates. On the other hand, the surface treatments did not improve the corrosion performance of the Ti-6Al-4V substrate.

Electrochemical Characterization of Degradation Modes of High-Voltage LixNi0.33Mn0.33Co0.33O2 Electrodes

While deeply charged high-voltage cathodes can improve battery energy density, understanding and preventing any accelerated cell degradation is crucial to practical success. To analyze the degradation of LiNixMnyCo1–x–yO2 (NMC) type material charged to 4.3 and 4.5 V, a physics-based model is applied to cycling data to obtain parameter estimates indicative of degradation modes, which are validated by simple electrochemical measurements and further interpreted by materials characterization. Growth rates of interfacial impedance and active material loss are greater at 4.5 V, as might be expected. However, when charged to 4.5 V, degradation rates are initially lower at a cycling C-rate of 1.0 C than at 0.5 C. Once degradation mode changes are quantified, simulations evaluate the contribution of individual degradation mode to performance losses and provide estimates of the energy-power correlation (Ragone plots) of cells after cycling.

Estimation of the wear and corrosion synergism of borided Inconel 718 alloy immersed in a neutral aqueous solution

This work investigates the tribocorrosion properties of the nickel boride layer on an Inconel 718 superalloy immersed in a neutral solution of sodium sulfate and sodium chloride. The solution simulates the corrosive environment created by the combustion reaction of sodium, sulfur, and oxygen when Ni-based superalloys are used in turbine blades. A powder-pack boriding process was conducted at 950 °C for 6 h, obtaining a nickel boride layer thickness of around 50 μm on the surface of the superalloy; microstructural analysis revealed that the boride layer was composed of Ni4B3–Ni2B–Ni3B. Further, depth-sensing Vickers microindentation tests were performed to assess the ratios of H/E and H³/E2 on the nickel boride layer.Additionally, tribocorrosion tests were conducted with a reciprocating tribometer and a typical three-electrode electrochemical cell. The counterpart was a 4.8 mm diameter alumina ball that applied 20 N for a sliding distance of 100 m. According to the ASTM G119-09 procedure, the total material loss rate due to tribocorrosion (T), which includes mass loss rate due to wear (Wc) and corrosion (Cw), was estimated.The results revealed a wear-dominant regime for the Reference material (Inconel 718 superalloy), attributed to passive film removal and high contact pressure at the tribopair, which increases the volume loss rate. On the other hand, the nickel boride layer on the Inconel 718 superalloy displayed a wear-corrosion regime due to boride layer debris that increased the corroded area. Under these experimental conditions, the presence of the nickel boride layer on the Inconel 718 superalloy improved tribocorrosion resistance by approximately three times.

The Tribo-Corrosion Behavior of Monel 400 Alloy in Marine Environment at Varied Rotational Velocities

Monel 400 alloy is widely employed in marine engineering equipment due to its excellent corrosion resistance, high strength and toughness. In this paper, the tribo-corrosion behavior of Monel 400 alloy in seawater under different rotational velocities was investigated by a pin-disk tribometer with an integrated electrochemical cell. The results revealed that the material loss rate and friction coefficient of the Monel 400 alloy, after tribo-corrosion and mechanical wear tests, increased with increasing rotational velocity. Under mechanical-wear conditions, the material loss rate increased with the sliding distance extension at higher velocities, and then more serious crack nucleation and propagation occurred at the subsurface. Under tribo-corrosion conditions, when the rotational velocities increased from 0.125 m/s to 0.5 m/s, the thickness of the corrosion product’s layer was reduced from 50 nm to 30 nm; that is, the lubrication of the corrosion product became worse. As a result, the material-loss rate and friction coefficient increased significantly at the velocity of 0.5 m/s. Importantly, the antagonistic effect, rather than the synergistic effect, between corrosion and mechanical wear, has been verified for the tribo-corrosion of Monel 400 alloy in seawater, and the mechanism was analyzed.

INFLUENCE OF VELOCITY, CONCENTRATION, AND SIZE OF SILT PARTICLES ON EROSION OF THERMAL SPRAYED Ni/TiO2/Al2O3 COATINGS

The presence of silt sediments in the flowing river is the primary reason for the severe failure of hydro-power turbine components. This study insights the effect of erosion parameters on the performance of two multi-dimensional novel compositions (namely Ni-40TiO2 and Ni-20TiO2-20Al2O3) developed on the CA6NM turbine steel by high velocity flame spray (HVFS) method. The Ni-40TiO2 coating with lower porosity, higher fracture toughness, and microhardness, showed the highest slurry erosion resistance than the other counterparts. This outstanding performance is attributed to the uniform distribution of the multi-dimensional TiO2 grains in the coating, which effectively reduces the material loss rate during slurry erosion. The Ni-40TiO2 coating indicated a mixed mechanism of material removal, while the brittle mechanism was observed in the case of Ni-20TiO2-20Al2O3 coating. A model has been proposed to estimate the erosion rate of these proposed coatings.

Fe3O4 core–shell catalysts supported by nickel foam for efficient heterogeneous electro-Fenton degradation of salicylic acid at neutral pH

A novel nickel foam (NF) supported core–shell catalytic material with excellent catalytic performance was successfully prepared for the degradation of salicylic acid (SA) by heterogeneous electro-Fenton (HEEF). Under the reaction conditions of SA initial concentration of 100 mg/L, catalyst dosage of 4 g/L, aeration rate of 0.1 L/min, current of 0.3 A and pH of 7, after 2 h, the removal efficiency of the progressively modified core–shell catalysts for SA and COD was as follows: NF@Fe3O4@SiO2@MgAl-LDH > NF@Fe3O4@MgAl-LDH > NF@Fe3O4 > NF@Fe3O4@SiO2. The removal efficiency of NF@Fe3O4@SiO2@MgAl-LDH for SA and COD reached 72.8 % and 52.12 %, respectively. The morphology, composition and structural characteristics of the composite catalysts were analyzed and compared by a series of characterization methods. Among them, NF@Fe3O4@SiO2@MgAl-LDH showed the largest Fe:Ni atomic content ratio, specific surface area and pore volume, with values of 1: 2.62, 7.5405 m2·g−1 and 0.010504 cm3·g−1, respectively. Radical quenching experiments, changes in H2O2 and Fe2+ ion concentrations, and X-ray photoelectron spectroscopy (XPS) analysis revealed the reaction mechanism of the HEEF process. That is, synergistic oxidation of active radicals and abundant adsorbed oxygen and lattice oxygen on the surface of the materials promoted the degradation and mineralization of SA. The excellent stability and reusability of NF@Fe3O4@SiO2@MgAl-LDH in the HEEF system were verified through five cyclic experiments with low material loss rate and sludge production.

The influence of Λ ratio and surface roughness on the initiation and progression of micropitting damage

Micropitting is a major failure mode in gears and rolling bearings. Despite its practical importance, there currently exist no universally accepted design guidelines for its prevention primarily due to the great number of influencing parameters. In the absence of an established criterion, the Λ-ratio (the ratio of lubricant film thickness to surface roughness) is often used as a simple way to assess the risk of micropitting. In this paper we present new data to establish and decouple the individual effects of two of the most important influencing parameters in micropitting: the surface roughness amplitude and Λ-ratio. The experiments are conducted on a triple disc contact fatigue rig and carefully designed to decouple the effect of roughness from that of the Λ-ratio. To isolate the influence of the Λ ratio, we use specimens with the same and very tightly controlled surface roughness and then vary the film thickness by blending different viscosities of the same PAO base oil while keeping all other influential parameters constant. To isolate the influence of surface roughness, we keep the Λ ratio the same using the same PAO oils with appropriate viscosities while changing the RMS roughness of the specimen and keeping other roughness parameters as constant as possible. All tests use case carburised 16MnCr5 gear steel specimens. Results show that higher Λ ratio at fixed roughness produces less micropitting as may intuitively be expected. More importantly, at a fixed Λ ratio the amount of micropitting damage was extremely sensitive to the actual surface roughness, with lower roughness both lengthening the micropitting incubation phase and decreasing the rate of material loss in the micropitting wear phase. This shows that Λ ratio on its own cannot be used to assess the risk of micropitting because it is not able to account for the effects of different roughness levels on micropitting, despite including roughness in its definition. Furthermore, in relative terms micropitting was more sensitive to surface roughness than to Λ. In addition, we show that there exists a sufficiently low surface roughness below which micropitting is unlikely to occur even at extremely low Λ ratios. The results presented here can help in design of gears and other mechanical components to mitigate against micropitting.

Evaluation of pitting susceptibility and tribocorrosion behaviors of AISI 304 stainless steel in marine environments

There is an increasing concern over simultaneous wear and corrosion (tribocorrosion) issues that cause the material failure of stainless steel in marine environments. The main objective of this study is to understand the effect of tribocorrosion conditions on pitting susceptibility and synergistic material loss for AISI 304 stainless steel. For this purpose, tribocorrosion tests were conducted in a natural seawater-filled corrosion cell integrated with a tribometer. An alumina ball of 6 mm radius slid against AISI 304 stainless steel plates under 5 N and 7.5 N loads in natural seawater. The cyclic polarization scans were carried out under corrosion and tribocorrosion conditions in the natural seawater by applying different loads. Also, tribocorrosion tests were conducted under anodic (0.3 V), cathodic (−0.5 V) and Open Circuit Potential (OCP) to determine the effect of electrochemical potential on pitting susceptibility and material loss rate. The study revealed that electrochemical potential significantly affects pitting corrosion and material loss, and the material losses increased significantly from the cathodic potential to the anodic potential. Furthermore, the material loss of AISI 304 alloy during tribocorrosion in natural seawater due to corrosion was significantly lower than wear. The wear-corrosion synergism played an essential role in total material loss, confirming that wear and corrosion affect accelerated material loss positively. The material loss of AISI 304 is mainly due to pure mechanical wear and corrosion-induced wear.

CFD Simulation and Experimental Results Validation of Slurry Erosion Wear using Slurry Pot Test Rig

Erosion wear is a severe issue in different industrial applications results in economic costs and operational failure. In most of the industry pipelines are used to handle the slurry during industrial process, the slurry handling pipeline is failure due to erosion wear. The slurry pot test rig is developed and fabricated for investigating the erosion wear rate of different material and solid particles used in the slurry pipeline with various working conditions. The various influencing parameters such as solid particle flow velocity, impact angle, solid particle size, and concentration are responsible for the rate of material loss and erosion wear mechanisms. The present study is based on experimental work and its validation of results of slurry erosion wear for slurry handling pipeline using slurry pot test rig and CFD simulation. For experimentation, mild steel is used as pipeline material and coal bottom ash is used as solid particles for simulating slurry handling pipeline use in a thermal power plant. The experimentation is performed on the slurry pot test rig. The computational fluid dynamics (CFD) tool is used to predict and simulate the experimental results of the slurry pot test rig. The simulation results compared with experimental results and check the percentage of errors with both the results. The simulation results show a similar kind of trend for erosion wear behavior of mild steel as per the experimental results. Simulation results show the average error up to ± 21% variation with the experimental result. The simulation results give the position of erosion wear over the sample surface.
 HIGHLIGHTS
 
 Erosion wear is the major problem in slurry handling industries (thermal power plant, chemical industries, hyro-power plants, coal minis) and components (Pipelines, Centrifugal pumps, flow control valve, turbines etc.)
 Experimental worked conducted to find the erosion wear rate and material removal mechanism of pipeline material (MS) with simulating thermal power plant conditions. Similarly software simulation analysis performed for same conditions
 The experimental results give the exact value of erosion wear rate but it does not show the position of maximum wear over the sample surface. Therefore, the experimental results are used for finding the erosion wear rate i.e. value of the sample and simulation results are used for finding the position of maximum erosion wear over the target sample
 
 GRAPHICAL ABSTRACT

Tribocorrosion behavior of HVOF sprayed WC-based cermet coatings in sodium chloride solution environment in relation to binder phases

The performance of three WC-based coatings prepared by high velocity oxygen-fuel (HVOF) has been evaluated under both pure mechanical wear and tribocorrosion in 3.5 wt% sodium chloride solution environment. The synergism of corrosion and wear is also calculated. The three coatings were WC cermets with Co, CoCr and Cr3C2-7Ni matrices. The experimental results indicated that the binder phases in the as-sprayed coatings greatly influenced their corrosion and wear performances. In the pure mechanical wear, the WC-12Co coating showed the best wear resistance followed by the WC-10Co4Cr and WC-Cr3C2-7Ni coatings. In tribocorrosion, all three coatings were under corrosion-dominated regime. The WC-12Co coating had the highest corrosion rate result from the selective preferential dissolution of Co phase. The wear process further accelerated the dissolution and removal of Co for the highest material loss rate of WC-12Co coating. The WC-10Co4Cr and WC-Cr3C2-7Ni coatings showed great corrosion resistance due to the CoCr and (W,Cr)2C phase, respectively. However, the (W,Cr)2C brittle phase was easily broken down mechanically which increased the material loss of WC-Cr3C2-7Ni coating. The formation of CoCr phase reduced the dissolution of the Co and was not easily destroyed under loading, making the WC-10Co4Cr coating have the best tribocorrosion resistance.