scholarly journals Corrosion Behavior and Galvanic Corrosion Resistance of WC and Cr3C2 Cermet Coatings in Madeira River Water

2021 ◽  
Author(s):  
Leonardo Augusto Luiz ◽  
Juliano de Andrade ◽  
Camila Melo Pesqueira ◽  
Irene Bida de Araújo Fernandes Siqueira ◽  
Gustavo Bavaresco Sucharski ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
River Water ◽  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Cermet Coatings ◽  
Madeira River

Influences of Zinc Content and Solution Heat Treatment on Microstructure and Corrosion Behavior of Mg-Zn Binary Alloys

CORROSION ◽  
10.5006/3672 ◽  
2020 ◽  
Author(s):  
Dinh Pham ◽  
Sachiko Hiromoto ◽  
Equo Kobayashi
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Volume Fraction ◽  
Galvanic Corrosion ◽  
Zinc Content ◽  
Eutectic Cell ◽  
Zn Content ◽  
Cast Alloys

The influences of Zn content and heat treatment on microstructure and corrosion behavior of Mg-xZn (x=1, 3, 5 and 7 wt.%) alloys were studied. (α-Mg + MgZn) eutectic cells and Zn-segregated regions were formed in the as-cast alloys. The Zn-rich phases acted as micro-cathodes in galvanic corrosion. Volume fraction of the Zn-rich phases increased with Zn content of the as-cast alloys, leading to a decrease in corrosion resistance. The corrosion rate of the as-cast alloys increased by 4 times with an increase of the volume fraction of eutectic cell from 0.07 vol.% of Mg-1Zn alloy to 2.18 vol.% of Mg-5Zn alloy. The corrosion rate of Mg-7Zn alloy with 2.87 vol% eutectic cells was 2 times higher than that of Mg-5Zn alloy. The Zn-rich phases dissolved by the T4 treatment and only the T4-treated Mg-7Zn alloy obviously showed eutectic cells of 1.73 vol.%. The polarization resistance (Rp) of the T4-treated Mg-1, 3 and 5Zn alloys was 2-10 times higher than that of the as-cast alloys. The T4-treated Mg-7Zn showed similar Rp to the as-cast Mg-5Zn alloy. Consequently, the volume fraction of Zn-rich phases dominated the corrosion resistance of Mg-xZn alloys.

Corrosion Behavior of WC-Co Cermet Coatings

2015 ◽  
Vol 819 ◽  
pp. 87-90 ◽  
Author(s):  
Zakiah Kamdi ◽  
C.Y. Phang ◽  
H. Ahmad
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Alkaline Electrolyte ◽  
Electrochemical Test ◽  
Cermet Coatings ◽  
Wear And Corrosion ◽  
Thermally Sprayed Coatings ◽  
Wear And Corrosion Resistance ◽  
Thermally Sprayed ◽  
Sprayed Coatings

Metal-ceramic composite or cermet coatings have become popular due to their enhanced wear and corrosion resistance properties. Cermet consists of ceramic particulate embedded in a metallic binder. WC-Co coatings are often used in applications that require wear resistance, but there are many applications in which thermally sprayed coatings have been deposited on components that operate under both abrasive and corrosive condition. Thus, in this study, the corrosion behavior of WC-12wt%Co in different electrolyte has been evaluated. Electrochemical test has been done in three electrolytes namely 0.5 M hydrochloric acid, HCl, 0.5 M sulfuric acid, H2SO4 and 0.5 M sodium hydroxide, NaOH. It is found that corrosion potential of this coating in acidic environment is more positive compares to in alkaline environment. Both in acid and alkaline electrolyte, binder dissolution were preferential. It may be concluded that this coating have higher corrosion resistance in alkaline electrolyte than in acid electrolyte.

scholarly journals Effect of Manganese on Microstructure and Corrosion Behavior of the Mg-3Al Alloys

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 460 ◽  
Author(s):  
Yao ◽  
Liu ◽  
Zeng ◽  
Li ◽  
Lei ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Galvanic Corrosion ◽  
Intermetallic Phase ◽  
Localized Corrosion ◽  
Experimental Investigations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemical Tests ◽  
Microstructure Observation

Microstructure and corrosion behavior of the Mg-3Al-xMn (x = 0, 0.12, 0.21, 0.36, 0.45) (hereafter in wt.%) alloys were experimentally investigated by electron probe microanalysis (EPMA), scanning electron microscope equipped with energy dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD), electrochemical, and hydrogen evolution tests. A new self-constructed Mg-Al-Mn-Fe thermodynamic database was used to predict the solidification paths of the alloys. The addition of Mn showed no grain refinement in the cast Mg-3Al alloys. According to the microstructure observation, Al-Fe phases were observed in the non-Mn-added alloy, while Al8Mn5(LT) (Al8Mn5 in low temperature) became the main intermetallic phase in the Mn-added alloys, and the amount increased gradually with the Mn addition. The τ–Al0.89Mn1.11 phase with lower Al/(Fe + Mn) ratio was observed in the alloys with 0.36 and 0.45 wt.% Mn content. According to the electrochemical tests, all five alloys showed localized corrosion characteristics in 3.5 wt.% NaCl solution. Compared with the Mg-3Al alloy, the corrosion resistance of Mn-added alloys were significantly improved and increased gradually with the Mn addition, which was due to the variation of Al-containing intermetallic compounds. The present experimental investigations and thermodynamic calculations confirmed the mechanism that the increasing amount of Al8Mn5(LT) with Mn addition could encapsulate the B2-Al(Mn,Fe) phase with higher Fe. Therefore, it could prevent this detrimental phase from contacting magnesium matrix, thus suppressing micro-galvanic corrosion and improving corrosion resistance gradually.

scholarly journals The Galvanic Corrosion Behavior of Phosphated Carbon Steel Used at Carabiners Manufacturing

2019 ◽  
Vol 70 (1) ◽  
pp. 215-219 ◽  
Author(s):  
Diana Petronela Burduhos Nergis ◽  
Carmen Nejneru ◽  
Dumitru Doru Burduhos Nergis ◽  
Cristian Savin ◽  
Andrei Victor Sandu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Corrosion Behavior ◽  
Sea Water ◽  
Galvanic Corrosion ◽  
Microscopic Analysis ◽  
Steel Corrosion ◽  
Material Surface ◽  
Fire Extinguishing ◽  
Fall Arrest

The carabiners are metallic links used to quickly connect the components of personal fall arrest equipment. Because these systems are used in corrosive environments, the carabiners must possess good corrosion resistance properties. In order to improve these properties, a phosphate layer was chemically deposited by converting on the carabiner material surface. This paper presents the microscopic analysis of the phosphated layer and the galvanic corrosion behavior of phosphated carbon steel, coupled to duralumin and initial carbon steel. Corrosion resistance has been studied for Black Sea water and fire extinguishing solution.

Effect of Microstructure Evolution on Corrosion Behavior of Friction Stir Welded Joint for 2195-T8 Alloy

CORROSION ◽  
10.5006/3567 ◽  
2020 ◽  
Vol 76 (12) ◽  
Author(s):  
B.Y. Hu ◽  
H. Zhang ◽  
L.Y. Liu ◽  
D.B. Liu ◽  
A.H. Feng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Open Circuit Potential ◽  
Galvanic Corrosion ◽  
Open Circuit ◽  
Nugget Zone ◽  
Friction Stir ◽  
Free Zone ◽  
Transmission Electron

Corrosion behavior of friction stir welded 2195-T8 Al-Cu-Li alloy has been studied. Immersion and electrochemical open-circuit potential (OCP) test were applied. The microstructure and precipitates evolution in different zones were investigated by scanning electron microscopy, stereoscope, and transmission electron microscopy. The corrosion tests showed that the sequence of corrosion resistance of each area of the joint is: welding nugget zone (WNZ) > base metal > heat affected zone (HAZ). The WNZ showed highest corrosion resistance due to the fine recrystallized grains, the dissolution of T1(Al2CuLi) phase, and the refined and evenly-distributed particles in this area. However, the HAZ had the lowest corrosion resistance due to the intergranular precipitates, deleterious precipitate-free zone (PFZ), S′ (Al2CuMg) phase, and the galvanic corrosion couples formed among T1, θ′, and PFZ.

scholarly journals Corrosion Mechanisms of High-Mn Twinning-Induced Plasticity (TWIP) Steels: A Critical Review

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 287
Author(s):  
David M. Bastidas ◽  
Jacob Ress ◽  
Juan Bosch ◽  
Ulises Martin
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Twip Steel ◽  
Galvanic Corrosion ◽  
Current Trend ◽  
High Strength Steels ◽  
Phase Segregation ◽  
Extrinsic Factors ◽  
Twip Steels ◽  
Corrosion Mechanisms

Twinning-induced plasticity (TWIP) steels have higher strength and ductility than conventional steels. Deformation mechanisms producing twins that prevent gliding and stacking of dislocations cause a higher ductility than that of steel grades with the same strength. TWIP steels are considered to be within the new generation of advanced high-strength steels (AHSS). However, some aspects, such as the corrosion resistance and performance in service of TWIP steel materials, need more research. Application of TWIP steels in the automotive industry requires a proper investigation of corrosion behavior and corrosion mechanisms, which would indicate the optimum degree of protection and the possible decrease in costs. In general, Fe−Mn-based TWIP steel alloys can passivate in oxidizing acid, neutral, and basic solutions, however they cannot passivate in reducing acid or active chloride solutions. TWIP steels have become as a potential material of interest for automotive applications due to their effectiveness, impact resistance, and negligible harm to the environment. The mechanical and corrosion performance of TWIP steels is subjected to the manufacturing and processing steps, like forging and casting, elemental composition, and thermo-mechanical treatment. Corrosion of TWIP steels caused by both intrinsic and extrinsic factors has posed a serious problem for their use. Passivity breakdown caused by pitting, and galvanic corrosion due to phase segregation are widely described and their critical mechanisms examined. Numerous studies have been performed to study corrosion behavior and passivation of TWIP steel. Despite the large number of articles on corrosion, few comprehensive reports have been published on this topic. The current trend for development of corrosion resistance TWIP steel is thoroughly studied and represented, showing the key mechanisms and factors influencing corrosion processes, and its consequences on TWIP steel. In addition, suggestions for future works and gaps in the literature are considered.

Corrosion. Corrosion Behavior of Thermal Sprayed Carbide Cermet Coatings.

1995 ◽  
Vol 44 (506) ◽  
pp. 1332-1337
Author(s):  
Mitsuharu INABA ◽  
Kazumi TANI ◽  
Tomoki TOMITA ◽  
Yasuyuki TAKATANI ◽  
Yoshio HARADA
Keyword(s):  
Corrosion Behavior ◽  
Cermet Coatings

Studies and Research on the Corrosion Behavior of Ni-Al2O3 Compound Coatings Obtained by Electrochemical Methods

2020 ◽  
Vol 43 (3) ◽  
pp. 21-25
Author(s):  
Simona BOICIUC ◽  
◽  
◽  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Corrosion Behaviour ◽  
Composite Coatings ◽  
Point Of View ◽  
Electrochemical Methods ◽  
Dispersed Phase ◽  
Nickel Matrix ◽  
Technical Alumina ◽  
Compound Coatings

The undertaken research which is described in this paper aims at the corrosion behaviour of composite coatings in nickel matrix using as dispersed phase technical alumina with dimensions of 5 μm and their characterization from a microstructural point of view. The corrosion resistance in the saline fog of the coatings is influenced by the microstructure, the stresses developed in the layer and the roughness.

Heat Treatment Influence on the Corrosion Resistance of a Cu-Al-Fe-Mn Bronze

2018 ◽  
Vol 69 (5) ◽  
pp. 1055-1059 ◽  
Author(s):  
Mariana Ciurdas ◽  
Ioana Arina Gherghescu ◽  
Sorin Ciuca ◽  
Alina Daniela Necsulescu ◽  
Cosmin Cotrut ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Structural Changes ◽  
Heating Temperature ◽  
Galvanic Corrosion ◽  
Cooling Water ◽  
Open Circuit ◽  
Water Quenching ◽  
Heat Treated ◽  
Different Temperatures

Aluminium bronzes are exhibiting good corrosion resistance in saline environments combined with high mechanical properties. Their corrosion resistance is obviously confered by the alloy chemical composition, but it can also be improved by heat treatment structural changes. In the present paper, five Cu-Al-Fe-Mn bronze samples were subjected to annealing heat treatments with furnace cooling, water quenching and water quenching followed by tempering at three different temperatures: 200, 400 and 550�C. The heating temperature on annealing and quenching was 900�C. The structure of the heat treated samples was studied by optical and scanning electron microscopy. Subsequently, the five samples were submitted to corrosion tests. The best resistance to galvanic corrosion was showed by the quenched sample, but it can be said that all samples are characterized by close values of open-circuit potentials and corrosion potentials. Concerning the susceptibility to other types of corrosion (selective leaching, pitting, crevice corrosion), the best corrosion resistant structure consists of a solid solution, g2 and k compounds, corresponding to the quenched and 550�C tempered sample.

scholarly journals Corrosion Behavior and Osteogenic Activity of a Biodegradable Orthopedic Implant Mg–Si Alloy with a Gradient Structure

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 781
Author(s):  
Weiyan Jiang ◽  
Wenzhou Yu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Gradient Structure ◽  
Orthopedic Implant ◽  
Biological Functions ◽  
Alloy Matrix ◽  
Osteogenic Activity

A gradient Mg-8 wt % Si alloy, which was composed of the agglomerated Mg2Si crystals coating (GMS8-1) and the eutectic Mg–Si alloy matrix (GMS8-2), was designed for biodegradable orthopedic implant materials. The bio-corrosion behavior was evaluated by the electrochemical measurements and the immersion tests. The results show that a significant improvement of bio-corrosion resistance was achieved by using the gradient Mg–Si alloy, as compared with the traditional Mg-8 wt % Si alloy (MS8), which should be attributed to the compact and insoluble Mg2Si phase distributed on the surface of the material. Especially, GMS8-1 exhibits the highest polarization resistance of 1610 Ω, the lowest corrosion current density of 1.7 × 10−6 A.cm−2, and the slowest corrosion rate of 0.10 mm/year. In addition, GMS8-1 and GMS8-2 show better osteogenic activity than MS8, with no cytotoxicity to MC3T3-E1 cells. This work provides a new way to design a gradient biodegradable Mg alloys with some certain biological functions.

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