Corrosion Behavior of a Ni–Cr–Mo Alloy Coating Fabricated by Laser Cladding in a Simulated Sulfuric Acid Dew Point Corrosion Environment

For this study, aimed at proposing a potential direction to prevent sulfuric acid dew point corrosion, a Ni–Cr–Mo alloy Hastelloy C22 coating was fabricated by coaxial laser cladding technology. The phase composition, microstructure, and corrosion behavior in a simulated sulfuric acid dew point corrosion environment were investigated and compared with a Hastelloy C22 alloy, a titanium alloy TC4, and 09CrCuSb steel (ND). The results showed that the phase composition of the C22 coating is essentially similar to that of the C22 alloy, consisting of a γ-Ni solid solution and Ni6Mo6C1.06. The finer microstructure of the C22 coating mainly contains eutectic and dentrite, presenting a typical solidification feature of laser cladding. The corrosion resistance of the C22 coating is very close to that of the C22 alloy, and outclasses that of TC4 and ND. The corrosion behavior of the C22 coating is intergranular corrosion resulting from the segregation of molybdenum, chromium containing corrosion products, and smaller anode micro-batteries.

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Influence of Microstructure on the Corrosion Behavior of a Ni-Si Alloy

MRS Proceedings ◽

10.1557/proc-39-537 ◽

1984 ◽

Vol 39 ◽

Cited By ~ 2

Author(s):

P. Kumar

Keyword(s):

Heat Treatment ◽

Solid Solution ◽

Corrosion Resistance ◽

Sulfuric Acid ◽

Corrosion Behavior ◽

Processing Condition ◽

Intermetallic Phases ◽

Sulfate Ion ◽

Corrosion Tests ◽

Excellent Corrosion Resistance

ABSTRACTNickel-based alloys with over 7 percent silicon have excellent corrosion resistance to sulfuric acid, oleum and sulfate-ion-containing environments. This alloy is characterized by the presence of intermetallic Ni3Si (beta) and Ni5Si2 (gamma) phases in Ni-Si solid solution (alpha) matrix. The corrosion resistance is provided by the coarse intermetallic phases. Size of intermetallic phases is dependent on the processing condition and the heat treatment. The corrosion resistance can be changed by heat treatment.Results of corrosion tests are explained in terms of microstructural features.

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Laser cladding Fe-based solid solution alloy coating with high corrosion resistance

Infrared and Laser Engineering ◽

10.3788/irla201746.0806001 ◽

2017 ◽

Vol 46 (8) ◽

pp. 806001

Author(s):

王彦芳 Wang Yanfang ◽

李豪 Li Hao ◽

石志强 Shi Zhiqiang ◽

肖亚梅 Xiao Yamei ◽

孙旭 Sun Xu ◽

...

Keyword(s):

Solid Solution ◽

Corrosion Resistance ◽

Laser Cladding ◽

Alloy Coating ◽

Solid Solution Alloy ◽

High Corrosion Resistance ◽

High Corrosion

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Microstructure and Corrosion Behavior of Laser-Cladding CeO2-Doped Ni-Based Composite Coatings on TC4

Journal of Chemistry ◽

10.1155/2020/8690428 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Fangxia Ye ◽

Wenxuan Shao ◽

Xuchao Ye ◽

Mingxia Liu ◽

Yanxiang Xie ◽

...

Keyword(s):

Corrosion Resistance ◽

Titanium Alloy ◽

Corrosion Behavior ◽

Laser Cladding ◽

Composite Coatings ◽

Maximum Value ◽

Laser Cladding Process

Laser-cladding CeO2-doped Ni-based composite coatings were prepared on the surface of a titanium alloy, and the effects of CeO2 addition on the microstructure, microhardness, and corrosion resistance of the prepared coatings were studied. The results showed that TiC, NiTi, Ni3Ti, and Ti2Ni phases were formed on the prepared coatings. Moreover, the addition of CeO2 in laser-cladding coatings effectively refined the microstructure and reduced the number of cracks generated in the laser-cladding process. When the amount of CeO2 was 2%, the number of cracks in the laser-cladding coating was significantly reduced compared with that of 0%. When the content of CeO2 was 2% or 3%, the microhardness of laser-cladding coatings reached the maximum value. At the same time, it was found that the appropriate addition of CeO2 was helpful to improve the corrosion resistance of the laser-cladding coating. However, excessive CeO2 addition could reduce the corrosion resistance of the laser-cladding coating.

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Phase composition, microstructure and in vitro bioactivity of laser cladding CaO–ZrO2–SiO2 system coatings on titanium alloy

Materials Letters ◽

10.1016/j.matlet.2015.05.061 ◽

2015 ◽

Vol 157 ◽

pp. 139-142 ◽

Cited By ~ 6

Author(s):

H.C. Li ◽

D.G. Wang ◽

C.Z. Chen ◽

F. Weng ◽

H. Shi

Keyword(s):

Titanium Alloy ◽

Phase Composition ◽

Laser Cladding ◽

In Vitro Bioactivity ◽

Sio2 System

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Effect of Bi Addition on the Corrosion Behavior of Zirconium Alloys

Volume 1: Plant Operations, Maintenance, Engineering, Modifications, Life Cycle and Balance of Plant; Nuclear Fuel and Materials; Radiation Protection and Nuclear Technology Applications ◽

10.1115/icone21-15460 ◽

2013 ◽

Cited By ~ 1

Author(s):

M. Y. Yao ◽

B. X. Zhou ◽

Q. Li ◽

W. P. Zhang ◽

L. Zhu ◽

...

Keyword(s):

Solid Solution ◽

Corrosion Resistance ◽

Corrosion Behavior ◽

Mass Fraction ◽

Zirconium Alloys ◽

Deionized Water ◽

Second Phase ◽

Micro Structure ◽

Second Phase Particles ◽

Structure Observation

In order to investigate systematically the effect of Bi addition on the corrosion resistance of zirconium alloys, different zirconium-based alloys, including Zr-4 (Zr-1.5Sn-0.2Fe-0.1Cr), S5 (Zr-0.8Sn-0.35Nb-0.4Fe-0.1Cr), T5 (Zr-0.7Sn-1.0Nb-0.3Fe-0.1Cr) and Zr-1Nb, were adopted to prepare the zirconium alloys containing Bi of 0∼0.5% in mass fraction. These alloys were denoted as Zr-4+xBi, S5+xBi, T5+xBi and Zr-1Nb+xBi, respectively. The corrosion behavior of these specimens was investigated by autoclave testing in lithiated water with 0.01 M LiOH or deionized water at 360°C/18.6 MPa and in superheated steam at 400 °C/10.3 MPa. The micro structure of the alloys was examined by TEM and the second phase particles (SPPs) were analyzed by EDS. Micro structure observation shows that the addition of Bi promotes the precipitation of Sn as second phase particles (SPPs) because Sn is in solid solution in α-Zr matrix in Zr-4, S5 and T5 alloys. The concentration of Bi dissolved in α-Zr matrix increase with the increase of Nb in the alloys, and the excess Bi precipitates as Bi-containing SPPs. The corrosion results show that the effect of Bi addition on the corrosion behavior of different zirconium-based alloys is very complicated, depending on their compositions and corrosion conditions. In the case of higher Bi concentration in α-Zr, the zirconium alloys exhibit better corrosion resistance. However, in the case of precipitation of Bi-containing SPPs, the corrosion resistance gets worse. This indicates that the solid solution of Bi in α-Zr matrix can improve the corrosion resistance, while the precipitation of the Bi-containing SPPs is harmful to the corrosion resistance.

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Influence of Sc Addition on the Corrosion Behavior of Medium Strength Al-Zn-Mg Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.913.439 ◽

2018 ◽

Vol 913 ◽

pp. 439-444 ◽

Cited By ~ 1

Author(s):

Zhao Ming Li ◽

Hai Chang Jiang ◽

Yun Li Wang ◽

Duo Zhang ◽

De Sheng Yan ◽

...

Keyword(s):

Weight Loss ◽

Corrosion Resistance ◽

Corrosion Behavior ◽

Intergranular Corrosion ◽

Relative Weight ◽

Mg Alloy ◽

Exfoliation Corrosion ◽

Medium Strength ◽

Relative Weight Loss ◽

Sc Addition

In this paper, the effect of Sc addition (0.06 wt%) on the corrosion behavior of medium strength Al-Zn-Mg alloy is investigated by mass loss measurements, electrochemical experiment, intergranular corrosion and exfoliation corrosion tests. The results indicate the addition of Sc reduces the relative weight loss and enhances pitting performance as a result of grain refinement. The improved intergranular corrosion and exfoliation corrosion resistance caused by minor Sc addition are mainly attributed to the delay in both the initiation and advance stages of local corrosion.

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Composite ZrO2-Based Cermet Material Modified with Mo

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.237.3 ◽

2015 ◽

Vol 237 ◽

pp. 3-8 ◽

Cited By ~ 1

Author(s):

Adriana Wrona ◽

Kinga Czechowska ◽

Małgorzata Osadnik ◽

Małgorzata Kamińska ◽

Marcin Lis ◽

...

Keyword(s):

Corrosion Resistance ◽

Phase Composition ◽

Plasma Spraying ◽

Alloy Coating ◽

Metallic Material ◽

Cermet Material ◽

Powder Composites ◽

Annealing Procedure ◽

Plasma Sprayed ◽

Structure And Microstructure

The work presents studies of a new ceramic-metallic material. The base is a ZrO2-Mo cermet which is modified with metallic Mo or Mo85Re15 alloy coating. The structure and microstructure of Mo85Re15 alloy powders and the composite were characterized. The annealing procedure was found to influence phase composition of powder composites but not their morphology. The plasma sprayed powders, both metallic and alloyed, form coatings that adhere well to the cermet substrate. The coatings show a better homogeneity in comparison to powders and more favourable phase composition.Keywords: cermets, plasma spraying, corrosion resistance

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Arc Thermal Spray NiCr20 Alloy Coating: Fabrication, Sealant, Heat Treatment, Wear, and Corrosion Resistances

International Journal of Electrochemistry ◽

10.1155/2019/8796958 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Van Tuan Nguyen ◽

Quy Le Thu ◽

Tuan Anh Nguyen ◽

Quoc Cuong Ly ◽

Ly Pham Thi ◽

...

Keyword(s):

Heat Treatment ◽

Wear Resistance ◽

Corrosion Resistance ◽

Phase Composition ◽

Corrosion Test ◽

Annealing Temperature ◽

Alloy Coating ◽

Aluminum Phosphate ◽

Annealing Temperatures ◽

Wear And Corrosion

This study presents the effect of heat treatment on porosity, phase composition, microhardness, and wear and corrosion resistances of the thermal sprayed NiCr20 coating after sealing with aluminum phosphate. The annealing temperatures were varied in a range of 400 to 1000°C. The obtained results indicated the porosity of coating decreased with increasing the annealing temperature. After treatment at temperatures in range of 800-1000°C, more than 90% of initial pores in the coating were successfully filled with the sealants. The XRD data revealed not only the formation of new phases of other compounds, but also the interaction between coating and sealant. After heat treatment, wear resistance of coating was 12 times higher than that without heat treatment. The corrosion test in H2SO4 solution indicated that the presence of sealant in coatings increased their corrosion resistance. From these findings, application of these NiCr20 coatings to protect steel against wear and corrosion appears very promising.

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Study of Corrosion Behavior of Friction Surfacing AA6351 Aluminium Alloy Coating on AISI 1020 Low Carbon Steel

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1012.401 ◽

2020 ◽

Vol 1012 ◽

pp. 401-406

Author(s):

Carlos Trivellato de Carvalho Filho ◽

Pedro Paiva Brito

Keyword(s):

Surface Roughness ◽

Corrosion Resistance ◽

Carbon Steel ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Low Carbon Steel ◽

Alloy Coating ◽

Low Carbon ◽

Friction Surfacing ◽

Finishing Process

In the present work, the friction surfacing process was applied to manufacture aluminum alloy (AA6351) coatings on low carbon steel (AISI 1020) substrates. After friction surfacing the AA6351 deposited coatings were submitted to two finishing process in order to adjust surface roughness: milling and milling followed by sanding. The corrosion behavior of the two finishing process was compared with the as-deposited condition in order to determine the influence of surface roughness on the corrosion resistance of friction surfacing coatings. The corrosion behavior was examined by electrochemical impedance spectroscopy and potentiodynamic polarization in a 3.5wt.%NaCl solution containing naturally dissolved O2. The results obtained indicated that the elevated surface roughness observed in the as-deposited condition led to relatively lower corrosion resistance in comparison, with lower values for polarization resistance and more anodic corrosion potential.

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