Properties of the Corroding Interface

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Ceramics ceramics	2.7	3.0	2018	25.2 Days	CHF 1600
Coatings coatings	2.9	5.0	2011	13.7 Days	CHF 2600
Crystals crystals	2.4	4.2	2011	10.8 Days	CHF 2100
Materials materials	3.1	5.8	2008	15.5 Days	CHF 2600
Metals metals	2.6	4.9	2011	16.5 Days	CHF 2600

25 pages, 13161 KiB

Open AccessArticle

Influence of NaAlO₂ Concentration on the Characteristics of Micro-Arc Oxidation Coating Fabricated on a ZK60 Magnesium Alloy

by Shu-Fan Zhou, Sheng Lu, Wei-Gang Lv, Ze-Xin Wang, Dubovyy Oleksandr, Jun-Jie Gu, Jin-Wei Zhang and Liang-Yu Chen

Coatings 2024, 14(3), 353; https://doi.org/10.3390/coatings14030353 - 16 Mar 2024

Viewed by 1086

Abstract

This study investigated the impact of NaAlO₂ concentration in electrolytic solutions on micro-arc oxidation (MAO) coatings, focusing on their surface quality enhancement and corrosion resistance improvement. The surface morphology and microstructure of these coatings were assessed using scanning electron microscopy. Mechanical properties, [...] Read more.

This study investigated the impact of NaAlO₂ concentration in electrolytic solutions on micro-arc oxidation (MAO) coatings, focusing on their surface quality enhancement and corrosion resistance improvement. The surface morphology and microstructure of these coatings were assessed using scanning electron microscopy. Mechanical properties, such as hardness and wear resistance of MAO coatings, were tested. The hardness of the 6 g/L group was 411.2 HV. X-ray photoelectron spectroscopy examinations showed that MgAl₂O₄, CaMgP₂O₇, and MgSiO₄ were the phases in the MAO coating. Antibacterial assessments were performed to evaluate the influence of NaAlO₂ concentration, and the antibacterial rate of the 6 g/L group reached 97.08%. The hydrophilicity of the coatings was determined using water contact angle measurements, wherein the water contact angle of the 6 g/L was the lowest, at 58.25°. Corrosion resistance was evaluated with an electrochemical workstation. The findings revealed that the MAO coatings prepared with a NaAlO₂ concentration of 6 g/L exhibited superior uniformity with fewer defects, enhanced corrosion resistance, and increased adhesive strength compared to other concentration groups. The 6 g/L NaAlO₂ concentration MAO coating demonstrated the highest fitting coating resistance R₃ (8.14 × 10⁴ Ω∙cm²), signifying better corrosion resistance. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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12 pages, 2632 KiB

Open AccessArticle

Electrochemical Properties of LaMO₃(M=Cr, Mn, and Co) Perovskite Materials

by Hongquan Zhao, Qiudong Zhu, Xin Ye, Lei Wang and Songtao Dong

Coatings 2024, 14(1), 147; https://doi.org/10.3390/coatings14010147 - 21 Jan 2024

Cited by 4 | Viewed by 1417

Abstract

The utilization of lanthanide perovskite oxides as electrode materials for supercapacitors has garnered significant interest owing to their excellent electrical conductivity, low cost, and excellent thermal stability. In this study, LaMO₃(M=Cr, Mn, and Co) nanoparticles were prepared by the sol–gel method [...] Read more.

The utilization of lanthanide perovskite oxides as electrode materials for supercapacitors has garnered significant interest owing to their excellent electrical conductivity, low cost, and excellent thermal stability. In this study, LaMO₃(M=Cr, Mn, and Co) nanoparticles were prepared by the sol–gel method coupled with a calcination process. To evaluate the microstructures, morphologies, and electrochemical properties of the samples, a variety of techniques were employed, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area measurements, cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) cycling, and electrochemical impedance spectroscopy (EIS). The results revealed that the LaCoO₃ electrodes exhibited a maximum specific capacitance of 118.4 F/g at a current density of 1 A/g, attributed to its higher concentration of oxygen vacancy, larger specific surface area, and lower charge transfer resistance. This discovery substantiates the notion that the electrochemical efficacy is enhanced with the diminishing B-site cation radius in the perovskite LaMO₃ system. The charge–discharge process was employed to investigate the anion-intercalation mechanism of LaMO₃(M=Cr, Mn, and Co). Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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10 pages, 5571 KiB

Open AccessArticle

Effect of Carbon-Doped Cu(Ni) Alloy Film for Barrierless Copper Interconnect

by Lei Wang, Xu Guo, Songtao Dong, Yanxin Qiao, Jian Chen, Zhen Yan, Rong Shu and Lei Jin

Coatings 2024, 14(1), 68; https://doi.org/10.3390/coatings14010068 - 3 Jan 2024

Cited by 1 | Viewed by 1120

Abstract

In this study, the barrier properties and diffusion behavior of carbon-doped Cu(Ni) alloy film were investigated. The films were fabricated using magnetron sputtering on a barrierless silicon substrate. X-ray diffraction patterns and electric resistivity results demonstrated that the barrierless Cu(NiC) alloy films remained [...] Read more.

In this study, the barrier properties and diffusion behavior of carbon-doped Cu(Ni) alloy film were investigated. The films were fabricated using magnetron sputtering on a barrierless silicon substrate. X-ray diffraction patterns and electric resistivity results demonstrated that the barrierless Cu(NiC) alloy films remained thermally stable up to 650 °C. Transmission electron microscopy images provided the presence of a self-formed diffusion layer between the Cu(NiC) alloy and Si substrate. The effect of carbon-doped atoms on the diffusion behavior of the Cu(NiC) films was analyzed by X-ray photoemission spectroscopy depth profile. Results revealed that carbon doping can improve the barrier properties of barrierless Cu(Ni) film. Moreover, X-ray photoemission spectroscopy was performed to examine the chemical states of the self-formed layer at the Cu(NiC)/Si interface. The self-formed diffusion layer was found to consist of Cu metal, Ni metal, Si, Cu₂O, NiO, and SiO₂. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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12 pages, 5937 KiB

Open AccessArticle

Effect of Ultrasonic Vibration Assistance on Microstructure Evolution and Mechanical Properties in Laser-Welded AZ31B Magnesium Alloy

by Yulang Xu, Jingyong Li, Yanxin Qiao, Weidong Wang, Xuzhi Lan and Xuyang Guo

Metals 2024, 14(1), 35; https://doi.org/10.3390/met14010035 - 28 Dec 2023

Viewed by 942

Abstract

Given the susceptibility to weld porosity and poor weld formability in laser beam welding (LBW), this study delves into an examination of the impact of ultrasonic vibrations on microstructural morphologies and mechanical properties in AZ31B magnesium (Mg) alloy. A comparative analysis was conducted [...] Read more.

Given the susceptibility to weld porosity and poor weld formability in laser beam welding (LBW), this study delves into an examination of the impact of ultrasonic vibrations on microstructural morphologies and mechanical properties in AZ31B magnesium (Mg) alloy. A comparative analysis was conducted between ultrasonic vibration-assisted LBW and conventional LBW. The results established that the effective elimination of weld porosity, an outcome attributed to the combined effects of cavitation and acoustic streaming, resulted in a weld characterized by a visually seamless and structurally robust appearance. Furthermore, the incorporation of ultrasonic vibration assistance in the welding process yielded a finer microstructure as compared to the conventional LBW. Moreover, the lamellar structures of β-Mg₁₇Al₁₂ were transformed into particles and evenly distributed throughout the α-Mg matrix. In addition, the incorporation of 50% ultrasonic vibration assistance yielded notable improvements in tensile strength (259.6 MPa) and elongation (11.1%). These values represented enhancements of 4.8% and 35.4% as compared to joints fabricated by using conventional LBW. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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11 pages, 5450 KiB

Open AccessArticle

Enhanced Electrochemical Performance of LaMnO₃ Nanoparticles by Ca/Sr Doping

by Junhan Zheng, Hongquan Zhao, Xu Guo, Xiaoyun Jin, Lei Wang, Songtao Dong and Jian Chen

Coatings 2024, 14(1), 20; https://doi.org/10.3390/coatings14010020 - 24 Dec 2023

Cited by 2 | Viewed by 1196

Abstract

In this paper, the sol-gel method was used to synthesize powders of LaMnO₃ (LMO), La_0.85Ca_0.15MnO₃ (LCM), and La_0.85Sr_0.15MnO₃ (LSM). The effect of substituting Ca and Sr at the A-site on the perovskite [...] Read more.

In this paper, the sol-gel method was used to synthesize powders of LaMnO₃ (LMO), La_0.85Ca_0.15MnO₃ (LCM), and La_0.85Sr_0.15MnO₃ (LSM). The effect of substituting Ca and Sr at the A-site on the perovskite crystal structure and electrochemical capabilities of LMO was investigated. LCM retained its orthogonal structure in comparison to the parent LMO components, whereas LSM transitioned to a rhombic structure. At 0.5 A/g, the specific capacitance of LCM and LSM electrodes is 185.5 F/g and 248 F/g, respectively. The specific capacitance of LCM was three times greater than that of the LMO electrode. Among the three samples (LMO, 22.25 m² g⁻¹; LSM, 31.56 m² g⁻¹), the LCM sample exhibited the highest specific surface area of 38.79 m² g⁻¹. The charge transfer resistances of the LMO, LCM, and LSM are 0.48 Ω, 0.36 Ω, and 0.38 Ω, respectively. The LCM electrode exhibits the greatest capacitance performance due to its more refined morphology, increased concentration of oxygen vacancy, and more complete utilization of the perovskite bulk structure. The above results demonstrate that Ca or Sr substitution of A-site compounds has great potential for supercapacitor applications. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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11 pages, 2303 KiB

Open AccessArticle

Effect of NaF Doping on the Microstructure and Thermoelectric Performance of BiCuSeO Ceramics

by Zhenbing Pei, Guangqi Xiang, Xin Sun, Zhuang Fu, Yanxin Qiao, Lei Wang, Songtao Dong and Jian Chen

Coatings 2023, 13(12), 2069; https://doi.org/10.3390/coatings13122069 - 12 Dec 2023

Viewed by 1062

Abstract

The layered oxyselenide BiCuSeO has attracted significant attention due to its ability to demonstrate low thermal conductivity and a high Seebeck coefficient. This research project involved the synthesis of Bi_1−xNa_xCuSeO_1−xF_x (x = 0, 0.05, [...] Read more.

The layered oxyselenide BiCuSeO has attracted significant attention due to its ability to demonstrate low thermal conductivity and a high Seebeck coefficient. This research project involved the synthesis of Bi_1−xNa_xCuSeO_1−xF_x (x = 0, 0.05, 0.10, 0.15, and 0.20) ceramics using high-energy ball milling and cold isostatic pressing techniques. A comprehensive investigation was conducted to examine the influence of co−doping NaF on the thermoelectric properties of BiCuSeO ceramics. The substitution of Bi³⁺ with Na⁺ introduces a substantial number of holes, resulting in a remarkable improvement in the electrical conductivity and power factor. The conductivity was significantly increased from 9.10 S cm⁻¹ (BiCuSeO) to 94.5 S cm⁻¹ (Bi_0.85Na_0.15CuSeO_0.85F_0.15) at 323 K. Additionally, at 823 K, the power factor of the Bi_0.85Na_0.15CuSeO_0.85F_0.15 sample reached 44.8 × 10⁻⁵ W/m K². Furthermore, the Bi_1−xNa_xCuSeO_1−xF_x ceramics demonstrated a minimum thermal conductivity of 0.43 W m⁻¹ K⁻¹. Consequently, the Bi_0.85Na_0.15CuSeO_0.85F_0.15 sample achieved a maximum ZT value of 0.78, which is 7.09 times higher than that of the pure BiCuSeO sample (0.11). Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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13 pages, 6614 KiB

Open AccessArticle

Characterization and Electrochemical Analysis of Acidic Condensate-Induced Corrosion on Aluminized Coating on Steel in Residential Heaters

by Dino Sulejmanovic, Jiheon Jun, Zhiming Gao and Yi-Feng Su

Coatings 2023, 13(9), 1631; https://doi.org/10.3390/coatings13091631 - 17 Sep 2023

Viewed by 787

Abstract

Condensing furnace residential heaters are starting to replace outdated and less efficient non-condensing units in homes across the US. However, the burning of natural gas in these new units produces acidic gases, which can form acid droplets (H₂SO₄, HNO [...] Read more.

Condensing furnace residential heaters are starting to replace outdated and less efficient non-condensing units in homes across the US. However, the burning of natural gas in these new units produces acidic gases, which can form acid droplets (H₂SO₄, HNO₃, H₂CO₃, etc.) that are corrosive to low-grade heat exchanger metallic materials. Type-1 aluminized steel has been used in industrial applications, such as marine, heating, and automobile parts, due to its resistance to oxidation at elevated temperature. Many components of the condensing furnaces, including heat exchangers, are made from type-1 aluminized steel. We investigated the interaction of type-1 aluminized steel substrates with two acidic condensate liquids by 500 h corrosion exposures as well as short-term electrochemical impedance measurements. SEM plan and cross-sectional view images revealed damage to the Al-Si rich layer and exposure of the steel substrate. The non-uniform damage in the Al-Si rich layer was likely attributed to a pitting corrosion mechanism and induced by high acidity of the condensate liquid. Electrochemical impedance measurements in an acidic condensate revealed lower corrosion resistance of the aluminized steel surface with a weld line, identifying welded sections as preferential corrosion initiation sites. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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14 pages, 4654 KiB

Open AccessArticle

Fracture Analysis and Working Stress Calculation of Bearing Cage Used in Charging Pump in a Nuclear Power Plant

by Qiang Chen, Shengli Jiang and Deli Duan

Metals 2023, 13(8), 1380; https://doi.org/10.3390/met13081380 - 31 Jul 2023

Cited by 1 | Viewed by 1364

Abstract

This paper presents an analysis of the fracture accident of a cylindrical roller bearing cage used in a charging pump in a nuclear power plant. The causes and mechanisms of bearing cage breakage were investigated by material failure analysis and simulation calculations. Macroscopic [...] Read more.

This paper presents an analysis of the fracture accident of a cylindrical roller bearing cage used in a charging pump in a nuclear power plant. The causes and mechanisms of bearing cage breakage were investigated by material failure analysis and simulation calculations. Macroscopic observation results confirmed that the cage fracture occurred at the stress concentration position. The microfracture morphology of the cage obtained from scanning electron microscopy showed a fatigue feature. The analysis of residual stress indicated large residual stress perpendicular to the fracture surface. The finite element calculation showed that when the bearing was moving in and out of the working area during operation, large working stress appeared at the stress concentration position. Working stress and residual stress acted together, approaching the fatigue limit of materials, and finally led to the cage fatigue fracture. The stress of the other two structural cages of the same type of bearing was also calculated, and no such large stress concentration was identified; thus, one plastic cage was temporarily used. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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15 pages, 23385 KiB

Open AccessArticle

Failure Analysis of Duplex Stainless Steel for Heat Exchanger Tubes with Seawater Cooling Medium

by Husaini Ardy, Thomas Albatros and Afriyanti Sumboja

Metals 2023, 13(7), 1182; https://doi.org/10.3390/met13071182 - 25 Jun 2023

Cited by 1 | Viewed by 2039

Abstract

The present paper describes a study case of the failure investigation of duplex stainless steel (UNS S31803) on the tube and tube sheet sections of BEM TEMA-type shell and tube heat exchanger with seawater as the cooling medium. The heat exchanger’s shell design [...] Read more.

The present paper describes a study case of the failure investigation of duplex stainless steel (UNS S31803) on the tube and tube sheet sections of BEM TEMA-type shell and tube heat exchanger with seawater as the cooling medium. The heat exchanger’s shell design pressure was 22.6 MPa at 422 K, and the tube design pressure was 1 MPa at 339 K. Although UNS S31803 offers high strength, high resistance to chloride-induced SCC, and high resistance to pitting attack in chloride environments, the heat exchanger in this study experienced some material degradation after 28 months of use; 102 out of 270 tubes failed, 26 tubes leaked and were plugged on both sides, and scale plugged 76 tubes. The examination in this study case revealed the formation of white-colored biofilm inside the tubes; XRD examination revealed that the film contained CaCO₃. Using microstructural examination on the inner surface of the tube, the austenite grains were shown to have been preferentially attacked; this phenomenon is typical in duplex stainless steel which fails due to crevice corrosion. According to the examination result, the failure in this case was caused by crevice corrosion between the substrate and surface deposits that was enhanced by microbiological-induced corrosion (MIC). Recommendations to avoid similar failures are also suggested in this paper. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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14 pages, 2939 KiB

Open AccessArticle

Effect of Enterococcus faecalis Biofilm on Corrosion Kinetics in Titanium Grade 4 Alloys with Different Surface Treatments

by Jadison Junio Conforte, Cecília Alves Sousa, Ana Claudia Rodrigues da Silva, Allan Victor Ribeiro, Cristiane Duque and Wirley Gonçalves Assunção

Materials 2023, 16(13), 4532; https://doi.org/10.3390/ma16134532 - 22 Jun 2023

Cited by 1 | Viewed by 1035

Abstract

E. faecalis has been associated with bacteremia, sepsis, and bacterial endocarditis and peri-implantitis. This microorganism can remain in the alveolus even after extraction of the root remnant. This study aimed to evaluate the corrosion on different surfaces of commercially pure titanium (Ti) grade [...] Read more.

E. faecalis has been associated with bacteremia, sepsis, and bacterial endocarditis and peri-implantitis. This microorganism can remain in the alveolus even after extraction of the root remnant. This study aimed to evaluate the corrosion on different surfaces of commercially pure titanium (Ti) grade 4 (Ticp-G4) as a function of the bacterial biofilm effect of Enterococcus faecalis. A total of 57 discs were randomly divided according to their surface finish (n = 19). For microbiological analysis (n = 9), the discs were placed in 12-well plates containing E. faecalis culture and incubated at 37 °C for 7 days. The results show that for the intergroup analysis, considering the “electrolyte” factor, there was a difference between the groups. There was greater biofilm formation for the D.A.Zir group, with greater electrochemical exchange for Biofilm, and the presence of biofilm favored greater electrochemical exchange with the medium. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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12 pages, 3070 KiB

Open AccessArticle

Hot Corrosion Behavior of Co–Al–W Superalloys with Si Additions

by Pengjie Zhou, Yingjie Wang, Qilong Liu, Yanxin Qiao and Shujin Chen

Coatings 2023, 13(6), 1031; https://doi.org/10.3390/coatings13061031 - 1 Jun 2023

Cited by 4 | Viewed by 1415

Abstract

The hot corrosion behavior of Co-9Al-9.5W-xSi (where x = 0%, 0.1%, 0.5%, at.%) alloys in a salt mixture at 900 °C was investigated. The effect of Si on hot corrosion resistance was examined using corrosion kinetics. The surface morphology of the corrosion products [...] Read more.

The hot corrosion behavior of Co-9Al-9.5W-xSi (where x = 0%, 0.1%, 0.5%, at.%) alloys in a salt mixture at 900 °C was investigated. The effect of Si on hot corrosion resistance was examined using corrosion kinetics. The surface morphology of the corrosion products was explored via SEM with EDS and the phase constituents were examined using XRD. The results revealed that hot corrosion occurred as a combination of both sulfidation and oxidation behavior. With the increase in Si content, the hot corrosion resistance of the alloy was capable of remarkable advancement. Corrosion scales on the three Co-based alloys were mostly comprised of Co₃O₄, CoO, CoAl₂O₄, CoWO₄, and Al₂O₃. The hot corrosion mechanism for the Co-based alloy in the presence of 75 wt.% Na₂SO₄ and 25 wt.% NaCl deposits were analyzed. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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19 pages, 12481 KiB

Open AccessArticle

Experimental and Numerical Study on the Ablation Analysis of a Pintle Injector for GOX/GCH₄ Rocket Engines

by Yibing Chang and Jianjun Zou

Coatings 2023, 13(6), 1022; https://doi.org/10.3390/coatings13061022 - 31 May 2023

Cited by 2 | Viewed by 1737

Abstract

In the present study, the ablation of a pintle injector on a 500N GOX/GCH₄ rocket engine under different working conditions is studied experimentally and numerically. The temperature of the pintle tip and the combustion gas in the head zone was measured in [...] Read more.

In the present study, the ablation of a pintle injector on a 500N GOX/GCH₄ rocket engine under different working conditions is studied experimentally and numerically. The temperature of the pintle tip and the combustion gas in the head zone was measured in a series of experiments by the thermocouples. Moreover, a three-dimensional model was established to simulate combustion and heat transfer concurrently and analyze the ablation state of the pintle injectors. The obtained results indicate that under a low chamber pressure (

p_{c} = 0.25 MPa

) and an increasing O/F ratio from 0.8 to 2, the tip temperature declines first, and then rises. At the designed working condition (

p_{c} = 1.05 MPa

and O/F = 3.2), the pintle tip suffered serious ablation, and the microstructure analysis indicates that the ablation failure of the stainless steel pintle tip originates from chromium precipitation. This phenomenon is especially more pronounced when the temperature exceeds 1273 K, which makes the structure fragile and vulnerable. This article helps to provide an understanding of the ablation failure of the pintle injectors, and the established model is capable of giving a prediction on the ablation status of the pintle tips consistent with the experiment. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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17 pages, 3511 KiB

Open AccessArticle

An Optimization Method for CNC Laser Combination Cutting of Irregular Plate Remainders

by Li Li, Zhaoyun Wu, Zhongwei Zhang and Yulan Zhang

Coatings 2023, 13(5), 914; https://doi.org/10.3390/coatings13050914 - 12 May 2023

Cited by 2 | Viewed by 1755

Abstract

The key research question in this study is how to cut pieces in irregular plate remainders, because there are many irregular plate leftovers created during the CNC (Computer Numerical Control) process. This will increase material utilization and allow plate leftovers to be reused. [...] Read more.

The key research question in this study is how to cut pieces in irregular plate remainders, because there are many irregular plate leftovers created during the CNC (Computer Numerical Control) process. This will increase material utilization and allow plate leftovers to be reused. One of the issues being researched is how to arrange plate remainders on the surface of the CNC machine; this issue is known as combination layout optimization. The other issue being researched is combination cutting-path optimization of plate remainders, which aims to determine the cutting path of parts of plate remainders. A genetic algorithm based on the gravity-center NFP (No-Fit Polygon) method was applied to optimize the layout pattern, and then the geometric coordinates of a part included in one plate remainder after packing were obtained by geometric transformation with the help of a three-layer graphic data correlation model, which quickly identified the inside and outside contours of parts. A colony algorithm based on the mathematical model of cutting-path optimization was used to optimize the cutting path of the parts in the plate remainders. Finally, some simulation tests were performed to illustrate the feasibility and effectiveness of the proposed method. The results of the algorithm for packing irregular shapes for some instances show that our algorithm outperforms the other algorithms. On most instances, the average plate utilization ratio using our algorithm, after running 20 times, is improved by 1% to 9% in comparison to the best plate utilization ratio using the tree search algorithm. The best idle travel of an example achieved by the algorithm in this paper is 7632 mm after running the cutting-path optimization algorithm 20 times, while that of the traditional equivalent TSP (Traveling Salesman Problem) algorithm is 11,625 mm, which significantly demonstrates the efficiency of the algorithm. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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20 pages, 8708 KiB

Open AccessReview

Research Progress of Macrocell Corrosion of Steel Rebar in Concrete

by Jun Wang, Qiuyue Wang, Yun Zhao, Pengfei Li, Tongyuan Ji, Gongnian Zou, Yanxin Qiao, Zhou Zhou, Guowei Wang and Dan Song

Coatings 2023, 13(5), 853; https://doi.org/10.3390/coatings13050853 - 30 Apr 2023

Cited by 3 | Viewed by 2491

Abstract

Macrocell corrosion of steel rebar in concrete induced by corrosive environments has attracted widespread attention in the engineering community due to its rapid corrosion rate, diverse forms, and multiple incentives. Potential differences between dissimilar coupled rebar or different parts of the same rebar [...] Read more.

Macrocell corrosion of steel rebar in concrete induced by corrosive environments has attracted widespread attention in the engineering community due to its rapid corrosion rate, diverse forms, and multiple incentives. Potential differences between dissimilar coupled rebar or different parts of the same rebar mainly cause macrocell corrosion of steel rebar. The more significant the potential difference, the faster the corrosion rate of the macrocell. Based on the existing research reports on macrocell corrosion of reinforced concrete, this review paper comprehensively discusses the macro- and micro-corrosion behavior of various types of steel rebar, and a variety of induction factors, such as dissimilar metals and concentration differences of the service environment, development rules. and electrochemical mechanisms for corrosion of rebar macrocells are summarized. ZRA (zero-resistance ammeter), micro-area electrochemical testing technology and evaluation techniques commonly used in the laboratory, and electrochemical testing techniques used in engineering testing are listed. Common experimental models for corrosion of rebar macrocells are briefly introduced. Based on the internal characteristics of macrocell corrosion of reinforced concrete, this paper further proposes the control strategy of macrocell corrosion, starting from the improvement of the corrosion resistance of the rebar and regulating the service environment of the reinforced concrete structure (RCS). Meanwhile, the future direction of macrocell corrosion of steel rebar is also preliminarily prospected. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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11 pages, 531 KiB

Open AccessArticle

Modeling Analysis of Heavy Metal Evaluation in Complex Geological Soil Based on Nemerow Index Method

by Jing Wei, Xiaogang Zheng and Jintong Liu

Metals 2023, 13(2), 439; https://doi.org/10.3390/met13020439 - 20 Feb 2023

Cited by 12 | Viewed by 1993

Abstract

To accurately understand soil environmental quality and improve the problem of the traditional method, which is that it has a single evaluation factor and cannot reflect the overall condition of the soil, a complex geological soil heavy metal evaluation modeling method based on [...] Read more.

To accurately understand soil environmental quality and improve the problem of the traditional method, which is that it has a single evaluation factor and cannot reflect the overall condition of the soil, a complex geological soil heavy metal evaluation modeling method based on the Nemerow index method is proposed. Index evaluation methods, ArcGIS technology, and a human health risk assessment were carried out to obtain the spatial distribution of heavy metals in the soil and the current status of pollution accumulation. The comprehensive pollution index (CPI) method, geo-accumulation index (GAI) method, and potential ecological hazard (PEH) index were adopted to analyze the pollution degree of soil heavy metals. On this basis, the Nemerow index method was used to establish a complex geological soil heavy metal evaluation model, and the standard Nemerow index was calculated to complete the evaluation of heavy metal pollution in complex geological soils. The research results showed that this method could make the evaluation factors obtain reasonable scores and obtain more reasonable soil evaluation results. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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18 pages, 6619 KiB

Open AccessArticle

Revealing the Enhanced Passivation and Anti-Corrosion Performance of Surface-Nanocrystallization-Modified Cr-Alloyed Rebar via Electrochemical Testing and XPS Depth Analysis

by Weilin Liu, Qiuyue Wang, Gongnian Zou, Edwin Eyram Klu, Zhiyong Ai, Falin Yang, Ningning Liang, Lei Gu, Bo Gao, Beibei Lian, Yifeng Chen and Dan Song

Coatings 2023, 13(1), 192; https://doi.org/10.3390/coatings13010192 - 15 Jan 2023

Cited by 1 | Viewed by 2218

Abstract

Surface nanocrystallization (SNC) modification can be used to realize the high-efficiency derusting of rusted Cr-alloyed rebar and obtain nanostructured grains on the surface of the rebar. The corrosion resistance performance of SNC rebar in a simulated Cl^--containing concrete pore solution was [...] Read more.

Surface nanocrystallization (SNC) modification can be used to realize the high-efficiency derusting of rusted Cr-alloyed rebar and obtain nanostructured grains on the surface of the rebar. The corrosion resistance performance of SNC rebar in a simulated Cl^--containing concrete pore solution was evaluated on the basis of electrochemical experiments. Potentiodynamic polarization testing showed that the passivation current density of the SNC rebar was about 18% of that of the rusted rebar. The structural composition of the passivation film of the SNC rebar in a concrete environment was studied using a novel characterization method, namely XPS deep sputtering, which confirmed that it had higher concentrations of Cr/Fe oxide and hydroxide, and therefore exhibited an enhanced degree of oxidation. Moreover, scanning electron microscopy and transmission electron microscopy were employed to investigate the microstructural characteristics of the SNC rebar, which was characterized by nanostructured grains with grain sizes ranging from 250 nm to 300 nm and which contained massive high-energy crystal defects, thereby promoting the film-forming reaction of Cr/Fe elements. The results of XPS depth analysis and microstructure characterization demonstrated that the SNC rebar exhibited excellent passivation performance in the concrete environment. These findings offer a new perspective on enhancing the passivation performance and chloride resistance of alloyed rebar, and provide guidance on the implementation of SNC rebar in actual engineering applications. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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13 pages, 4168 KiB

Open AccessArticle

Corrosion Behavior of Selective Laser Melted Ti-6Al-4V in 0.1 mol/L NaOH Solution

by Lei Huang, Shunli Zheng, Yue Qin, Jianyang Han, Yanxin Qiao and Jian Chen

Coatings 2023, 13(1), 150; https://doi.org/10.3390/coatings13010150 - 11 Jan 2023

Cited by 4 | Viewed by 1809

Abstract

In this work, the corrosion behavior of a Ti-6Al-4V alloy prepared using selective laser melting (SLM) in a 0.1 mol/L NaOH solution was studied by means of corrosion electrochemical testing, X-ray diffraction analysis and X-ray photoelectron spectroscopy (XPS), and its corrosion process was [...] Read more.

In this work, the corrosion behavior of a Ti-6Al-4V alloy prepared using selective laser melting (SLM) in a 0.1 mol/L NaOH solution was studied by means of corrosion electrochemical testing, X-ray diffraction analysis and X-ray photoelectron spectroscopy (XPS), and its corrosion process was compared with the commercially forged Ti-6Al-4V alloy. The results show that the corrosion resistance of the commercially forged Ti-6Al-4V alloy was higher than the SLMed Ti-6Al-4V alloy, which is closely correlated with the presence of more active spots on the alloy surface and more defects in the passive films. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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14 pages, 1613 KiB

Open AccessEditor’s ChoiceArticle

The Application of Rubber Aggregate-Combined Permeable Concrete Mixture in Sponge City Construction

by Bowen Qi, Shouwu Gao and Peilong Xu

Coatings 2023, 13(1), 87; https://doi.org/10.3390/coatings13010087 - 3 Jan 2023

Cited by 32 | Viewed by 3249

Abstract

Permeable concrete is a new type of pavement material, which can effectively improve the urban flood discharge system, and is of great significance to the construction of sponge city. In order to optimize the use effect of permeable concrete and improve the application [...] Read more.

Permeable concrete is a new type of pavement material, which can effectively improve the urban flood discharge system, and is of great significance to the construction of sponge city. In order to optimize the use effect of permeable concrete and improve the application value of permeable concrete in permeable road engineering, the combination of rubber aggregate and permeable concrete is proposed, and the mix ratio of rubber permeable concrete mixture material is designed, which is applied to the engineering of pavement in Hunan Province, and its comprehensive pavement performance is analyzed and evaluated. The results show that the rubber permeable concrete has the best performance when the water cement ratio is 0.3, the designed porosity is 15%, the rubber particle size is 16 mesh, the rubber content is 15% and the coarse aggregate ratio is 4:6. The removal rates of suspended solids and metal pollutants are 0.65 and 0.72, respectively, which are increased by 0.23 and 0.19, respectively, compared with ordinary permeable concrete. This shows that rubber permeable concrete improves the ecological benefits of permeable concrete pavement, gives full play to the economic benefits of waste rubber products, reduces the construction cost of permeable concrete pavement, and provides assistance for promoting the construction of sponge city. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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9 pages, 2715 KiB

Open AccessArticle

The Oxidation Properties of a NiCrAlY Coating Fabricated by Arc Ion Plating

by Lei Huang, Zhaohui Zhou, Lanlan Yang and Yanxin Qiao

Coatings 2023, 13(1), 22; https://doi.org/10.3390/coatings13010022 - 22 Dec 2022

Cited by 1 | Viewed by 1928

Abstract

The microstructures, phase compositions, and high-temperature oxidation behavior of a NiCrAlY coating fabricated by arc ion plating were investigated by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), atomic force microscope (AFM), and X-ray diffractometer (XRD). The results indicate that the NiCrAlY coating [...] Read more.

The microstructures, phase compositions, and high-temperature oxidation behavior of a NiCrAlY coating fabricated by arc ion plating were investigated by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), atomic force microscope (AFM), and X-ray diffractometer (XRD). The results indicate that the NiCrAlY coating was covered by a protective Al₂O₃ scale with excellent oxidation resistance after oxidation at 1050 °C for 100 h; the β phase rich in Al in the as-deposited coating was transformed into a γ/γ’ phase; the interdiffusion zone (IDZ), secondary reaction zone (SRZ), and needle-like TCP phases were detected in the superalloy substrate beneath the coating. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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16 pages, 5078 KiB

Open AccessArticle

Experimental and Numerical Investigation of CMT Wire and Arc Additive Manufacturing of 2205 Duplex Stainless Steel

by Yuheng Yuan, Ruifeng Li, Xiaolin Bi, Jiayang Gu and Chen Jiao

Coatings 2022, 12(12), 1971; https://doi.org/10.3390/coatings12121971 - 15 Dec 2022

Cited by 2 | Viewed by 1899

Abstract

In this paper, the mechanical properties, microhardness and metallographic structure of 2205 duplex stainless steel by cold metal transfer (CMT) wire and arc additive manufacturing process are studied. The results show that the ultimate tensile strength, yield strength and elongation at break of [...] Read more.

In this paper, the mechanical properties, microhardness and metallographic structure of 2205 duplex stainless steel by cold metal transfer (CMT) wire and arc additive manufacturing process are studied. The results show that the ultimate tensile strength, yield strength and elongation at break of reciprocating additive along building direction (BD) are 856.73 MPa, 710.5 MPa and 42.35%, respectively. In addition, the same direction motion (SDM) and reciprocating motion (RM) is selected as parameter variables in the experiment, and the finite element model is established by ABAQUS software, and the temperature and residual stress field of the additive forming at different paths are tested and simulated. Firstly, the accuracy of the selected finite element model was verified by comparing the experimental results from the simulation results to the macroscopic morphology of the cross-section of the single-pass additive specimen. The numerical simulation results show that due to the difference of the additive scanning paths, the distribution of the temperature field has a large difference, and with the increase of the deposited layer, the heat accumulation of the SDM additive is larger than that of the RM, so that the end collapses of the SDM additive will occur in the actual additive specimen. By simulating and comparing the equivalent stress distribution of different paths, the equivalent stress distribution of SDM and RM is approximately the same in the vertical direction, and the minimum of equivalent stress appears at the bottom of the deposition layers, about 116.5 MPa, and the maximum of equivalent stress appears at 8 mm from the top, about 348 MPa. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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13 pages, 5413 KiB

Open AccessArticle

Corrosion Behaviors of Fe-22Cr-16Mn-0.55N High-Nitrogen Austenitic Stainless Steel in 3.5% NaCl Solution

by Song Xu, Fengyin Gao, Jianyang Han, Shangfeng Xiong, Xinyu Duan, Fanglin Zha, Bing Yu, Lanlan Yang, Yanxin Qiao, Zhibin Zheng and Jian Chen

Coatings 2022, 12(11), 1769; https://doi.org/10.3390/coatings12111769 - 19 Nov 2022

Cited by 5 | Viewed by 2091

Abstract

In this study, the corrosion behavior of the high-nitrogen austenitic stainless steel (HNS) Fe-22Cr-16Mn-0.55N before and after solution treatment (ST) in 3.5% NaCl solution has been investigated. The effect of a solution temperature of 1100 °C and heat preservation for 30 min on [...] Read more.

In this study, the corrosion behavior of the high-nitrogen austenitic stainless steel (HNS) Fe-22Cr-16Mn-0.55N before and after solution treatment (ST) in 3.5% NaCl solution has been investigated. The effect of a solution temperature of 1100 °C and heat preservation for 30 min on the corrosion resistance and passive film protection of HNS steel was studied. Open-circuit potential, potentiodynamic polarization and electrochemical impedance tests were used to assess the corrosion resistance of treated and untreated steels. In addition, potentiostatic polarization and XPS techniques together with Mott–Schottky curves were applied to determine the composition and properties of the passive films. The results showed that after solution treatment, the grain size of HNS decreased and the grain became more uniform. Although corrosion occurred on HNSs both before and after treatment, solution treatment resulted in greater compactness in passive films, leading to lower carrier density, lower corrosion current density and better corrosion resistance. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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11 pages, 3459 KiB

Open AccessArticle

Enhancement in the Electrochemical Performance of Strontium (Sr)-Doped LaMnO₃ as Supercapacitor Materials

by Xin Ye, Songtao Dong, Xiaoyun Jin, Junlin Wei, Lei Wang and Yamei Zhang

Coatings 2022, 12(11), 1739; https://doi.org/10.3390/coatings12111739 - 13 Nov 2022

Cited by 13 | Viewed by 2082

Abstract

In this study, Strontium (Sr)-doped perovskite lanthanum manganite (La_1−xSr_xMnO₃) nanoparticles were prepared by the sol–gel method and used as electrode materials of supercapacitors. Microstructures, morphologies, and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), [...] Read more.

In this study, Strontium (Sr)-doped perovskite lanthanum manganite (La_1−xSr_xMnO₃) nanoparticles were prepared by the sol–gel method and used as electrode materials of supercapacitors. Microstructures, morphologies, and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), a transmission electron microscope (TEM), Brunauer–Emmett–Teller (BET) surface area measurements, cyclic voltammetry (CV), and galvanostatic charge/discharge (GCD) cycling. Investigations demonstrated that the La_0.85Sr_0.15MnO₃ nanoparticles had a maximum specific capacitance of 185.5 F/g at a current density of 0.5 A/g and a low charge transfer resistance (0.38 Ω) in 3 M KOH aqueous electrolyte solutions. La_0.85Sr_0.15MnO₃ electrode yields the highest capacitance behavior because of the larger specific surface area, lower charge transfer resistance, and higher concentration of oxygen vacancy. This result demonstrates that Sr doping significantly improved the electrochemical properties of the LaMnO₃ system. The anion-intercalation mechanism was examined by a charge–discharge process. This provides a promising electrode material for supercapacitors. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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14 pages, 6734 KiB

Open AccessArticle

Stepwise Removal Process Analysis Based on Layered Corrosion Oxides

by Yuan Ren, Liming Wang, Mingliang Ma, Wei Cheng, Baoli Li, Yuxin Lou, Jianfeng Li and Xinqiang Ma

Materials 2022, 15(21), 7559; https://doi.org/10.3390/ma15217559 - 27 Oct 2022

Cited by 3 | Viewed by 1403

Abstract

The parts of engineering machinery quickly generate rusty oxides in the working process, which seriously affects their service life and safety. How to remove oxides efficiently without damaging the surface of the matrix is a crucial problem. This paper analyzes the critical laser [...] Read more.

The parts of engineering machinery quickly generate rusty oxides in the working process, which seriously affects their service life and safety. How to remove oxides efficiently without damaging the surface of the matrix is a crucial problem. This paper analyzes the critical laser parameters that affect the distribution of material temperature field, which determines the ablation depth of different oxides, by using the central composite experimental design method and taking the surface-ablation depth of Fe₂O₃ and Fe₃O₄ before and after laser cleaning as response variables to establish the prediction model of single removal volume with the help of Comsol Multiphysics software. The results show a positive correlation between ablation depth and peak power density and a negative correlation with scanning speed. In this process, the experimental results show that the prediction model is natural and effective. A flow chart of laser stepwise cleaning of layered corroded oxides can provide theoretical guidance for the laser cleaning of engineering machinery. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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9 pages, 4629 KiB

Open AccessArticle

Effects of Sintering Temperature on MoO_x Target and Film

by Xianjie Zhou, Hanqing Xiong and Jiwen Xu

Coatings 2022, 12(11), 1624; https://doi.org/10.3390/coatings12111624 - 26 Oct 2022

Viewed by 1405

Abstract

The sintering process of the MoO_x target has an impact on the quality of the sputtered film. In this study, powders of MoO₃ (78 wt%) and MoO₂ (22 wt%) were milled and hot-pressed to prepare the MoO_x target. The [...] Read more.

The sintering process of the MoO_x target has an impact on the quality of the sputtered film. In this study, powders of MoO₃ (78 wt%) and MoO₂ (22 wt%) were milled and hot-pressed to prepare the MoO_x target. The effects of the sintering temperature of the MoO_x targets on the properties of the sputtered MoO_x films were investigated by X-ray diffraction, scanning electron microscopy, four-probe needle, and spectrophotometer tests. The research results revealed that the MoO_x target at the sintered temperature of 1000 °C had a clear crystal structure and dense grains, exhibiting good sinterability, crystallization behavior, and film-forming property. The sputtered film deposited by the MoO_x target could obtain high quality with a smooth interface and uniform thickness. The film had smaller resistivity, higher reflectivity, and appropriate transmissivity compared to the ones fabricated by other targets that were sintered at 800 °C, 900 °C, and 1100 °C. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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15 pages, 4147 KiB

Open AccessArticle

Corrosion of Fe-Cr-Si Alloys in Oxidizing and Sulphidizing-Oxidizing Atmospheres

by Wenbo Li, Chenghao Xu, Ken Chen, Lanlan Liu, Haiyun Yang, Qiao Cheng and Minyu Zeng

Coatings 2022, 12(10), 1588; https://doi.org/10.3390/coatings12101588 - 20 Oct 2022

Cited by 4 | Viewed by 2141

Abstract

To clarify the mechanism of the third-element effect in sulphur-containing and sulphur-free oxidation environments, the corrosion behaviours of four kinds of Fe-xCr-ySi (x = 5, 10 at.% and y = 5, 10 at.%) alloys were studied at 600 °C in a H₂ [...] Read more.

To clarify the mechanism of the third-element effect in sulphur-containing and sulphur-free oxidation environments, the corrosion behaviours of four kinds of Fe-xCr-ySi (x = 5, 10 at.% and y = 5, 10 at.%) alloys were studied at 600 °C in a H₂-CO₂ and a H₂-CO₂-H₂S gaseous mixture with the same oxygen partial pressure. The results showed that, in the pure oxidizing atmosphere, thin and slowly growing protective oxide layers were formed on the alloys surfaces. Conversely, all alloys formed a corrosion product layer with an outer layer of FeS and an inner layer of a mix of oxides and sulphides in the oxidizing-sulphidizing atmosphere, which meant that adding Cr into the alloy as the third element had less of an effect on improving the alloy in the harsh sulphidizing-oxidizing environment. The oxidation and sulphidation mechanism as well as the effects of chromium and silicon on the corrosion resistance of the alloys was discussed. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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12 pages, 2908 KiB

Open AccessFeature PaperArticle

Precipitation Behavior of Carbides and Its Effect on the Microstructure and Mechanical Properties of 15CrNi3MoV Steel

by Xin Yao, Jie Huang, Yanxin Qiao, Mingyue Sun, Bing Wang and Bin Xu

Metals 2022, 12(10), 1758; https://doi.org/10.3390/met12101758 - 19 Oct 2022

Cited by 6 | Viewed by 2565

Abstract

In this study, quenching and tempering were employed to achieve the optimal match of strength and toughness of the high-strength low-alloy (HSLA) 15CrNi3MoV steel. The effect of the tempering temperature on the microstructure evolution and the carbides precipitation of the steel was also [...] Read more.

In this study, quenching and tempering were employed to achieve the optimal match of strength and toughness of the high-strength low-alloy (HSLA) 15CrNi3MoV steel. The effect of the tempering temperature on the microstructure evolution and the carbides precipitation of the steel was also investigated using scanning electron microscopy (SEM), a X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The results showed that after tempering at different temperatures, the microstructure of 15CrNi3MoV steel was tempered martensite. During the tempering process, the M₃C carbides precipitated on the ferrite matrix, the needle-like carbides accumulated and grew into a short rodlike shape or a granular shape with the increase of the tempering temperature. Subsequently, the strength and hardness of the steel showed a downward trend, and the elongation and the low temperature impact toughness showed an upward trend. The tensile strength and yield strength of the steel tempered at 650 °C decreased dramatically compared with the steel tempered at 550 °C, while the elongation increased rapidly. Considering the influence of the microstructure and the carbides and the demand for mechanical properties, the optimal tempering temperature is about 600 °C. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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9 pages, 4419 KiB

Open AccessArticle

Corrosion Behavior of SiO₂-Al₂O₃ Glass Composite Coating on TC4 in Marine Environment

by Wenbo Li, Min Feng, Lanlan Liu, Jun Zhang, Bo Hu and Qiao Cheng

Coatings 2022, 12(10), 1503; https://doi.org/10.3390/coatings12101503 - 8 Oct 2022

Cited by 3 | Viewed by 1677

Abstract

Compressor blades made of TC4 that are serviced in marine environments suffer from severe active corrosion under the synergetic effect of NaCl and H₂O(g). A SiO₂-Al₂O₃ glass composite coating was applied on TC4 substrate for protection [...] Read more.

Compressor blades made of TC4 that are serviced in marine environments suffer from severe active corrosion under the synergetic effect of NaCl and H₂O(g). A SiO₂-Al₂O₃ glass composite coating was applied on TC4 substrate for protection by first air spraying slurry and subsequent a suitable sintering process. The corrosion behavior of the SiO₂-Al₂O₃ glass composite coating and uncoated alloy in marine environment under the simultaneous effect of NaCl(s) and H₂O(g) at 650 °C were investigated. The results indicated that the SiO₂-Al₂O₃ glass composite coating presented good corrosion behavior and provided protection for the alloy; the superior corrosion resistance is mainly attributed to the favorable effect of the SiO₂-Al₂O₃ glass composite coating on inhibiting self-sustainable oxychlorination. The detrimental effect of Ti on self-sustainable oxychlorination mechanism in marine environment are discussed. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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12 pages, 4811 KiB

Open AccessArticle

Microstructure and Texture of 2205 Duplex Stainless Steel Additive Parts Fabricated by the Cold Metal Transfer (CMT) Wire and Arc Additive Manufacturing (WAAM)

by Xiaolin Bi, Ruifeng Li, Zhenxing Hu, Jiayang Gu and Chen Jiao

Metals 2022, 12(10), 1655; https://doi.org/10.3390/met12101655 - 30 Sep 2022

Cited by 12 | Viewed by 2973

Abstract

Additive parts made of 2205 duplex stainless steel were fabricated by cold metal transfer (CMT) wire and arc additive manufacturing (WAAM), and their microstructure and properties were systematically studied. The X-ray diffraction results show that austenite phase and ferrite phase were formed in [...] Read more.

Additive parts made of 2205 duplex stainless steel were fabricated by cold metal transfer (CMT) wire and arc additive manufacturing (WAAM), and their microstructure and properties were systematically studied. The X-ray diffraction results show that austenite phase and ferrite phase were formed in the additive parts. Due to the low heat input characteristics of CMT-WAAM, no σ phase was observed. The microstructure in the additive parts was different from the bottom to the top, with the content of austenite phase gradually increasing and that of ferrite gradually decreasing. The EBSD results indicate that the ferrite phase in the bottom part grew parallel to the normal direction of {100}. However, the ferrite phase in the middle part grew parallel to the plane composed of the build direction and normal direction, and along {100} and {111}. The effect of the ferrite and austenite contents on the mechanical performance of the additive parts was simulated using the LAMMPS software. The simulation results exhibit a common characteristic in that the dislocations move mainly along the 1/6<112> crystallographic direction families. The simulated maximum tensile stress values of the bottom, middle, and top parts were 23.3 GPa, 22.3 Gpa, and 22.5 Gpa, respectively. The data from the bottom tensile strength simulation were consistent with the actual data, and the bottom tensile strength was the largest in the actual tensile process. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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12 pages, 2714 KiB

Open AccessFeature PaperArticle

Effects of Flow Velocity and Sand Concentration on Hydro-Abrasive Erosion Behavior of HVOF-Sprayed WC-Cr₃C₂-Ni Coating in 3.5 wt.% NaCl Aqueous Solution

by Jinran Lin, Sheng Hong, Yuan Zheng, Wei Sun, Zhengwei Zhang, Min Kang and Xiuqing Fu

Metals 2022, 12(10), 1576; https://doi.org/10.3390/met12101576 - 23 Sep 2022

Cited by 3 | Viewed by 1647

Abstract

To explore the hydro-abrasive erosion (HAE) behaviors of a high-velocity oxygen fuel (HVOF)-sprayed WC-Cr₃C₂-Ni coating in 3.5 wt.% NaCl aqueous solution, various flow velocities (FVs) and sand concentrations (SCs) were designed using a rotating disk rig facility. In comparison [...] Read more.

To explore the hydro-abrasive erosion (HAE) behaviors of a high-velocity oxygen fuel (HVOF)-sprayed WC-Cr₃C₂-Ni coating in 3.5 wt.% NaCl aqueous solution, various flow velocities (FVs) and sand concentrations (SCs) were designed using a rotating disk rig facility. In comparison with 1Cr18Ni9Ti stainless steel, the WC-Cr₃C₂-Ni coating possessed higher hardness (H) and elastic modulus (E) values, worse anticorrosion properties, and superior HAE resistances in 3.5 wt.% NaCl aqueous solution. Higher FVs and SCs caused more severe HAE degradations for both the WC-Cr₃C₂-Ni coating and the 1Cr18Ni9Ti stainless steel, while FV had a greater influence on HAE resistances than SC. With an increase in the FV and SC, uncontinuous corrosion product films and erosion pits, the micro-cutting of the soft binder matrix and the fracturing of hard-phase grains, and crater formation and coating spalling were addressed as the HAE failure mechanisms in the 3.5 wt.% NaCl aqueous solution of the WC-Cr₃C₂-Ni coating. Full article

(This article belongs to the Topic Properties of the Corroding Interface)

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