Influence of plasma spraying parameters on microstructure and corrosion resistance of Cr3C2-25NiCr cermet carbide coating

2019 ◽  
Vol 66 (3) ◽  
pp. 336-342 ◽  
Author(s):  
Tuan Nguyen Van ◽  
Tuan Anh Nguyen ◽  
Quy Le Thu ◽  
Ha Pham Thi
Keyword(s):  
Corrosion Resistance ◽  
Potentiodynamic Polarization ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
Salt Spray ◽  
Compositional Analysis ◽  
Atmospheric Plasma ◽  
Content Type ◽  
Spraying Parameters ◽  
Hardness Scale

Purpose In this work, Cr3C2-25NiCr coatings were deposited on 410 stainless steel substrate by using the atmospheric plasma spray technique, at varying spaying parameters. The porosity and microhardness, adhesion strength and corrosion behaviour of coatings were examined in relation to these spraying parameters. Design/methodology/approach The microstructure of prepared coatings was examined by using scanning electron microscopy. The coating compositional analysis was performed by using X-ray diffraction (XRD) technique. The corrosion resistance of coated steel was investigated by potentiodynamic polarization. Results indicate that optimal factors for minimalizing the porosity were as follows: 10 g/min feed rate, 600 A plasma current and 100 mm spraying distance. The spraying factors influencing corrosion resistance of coating were also evaluated. Findings Under this optimal condition, the porosity of coating reached its minimal value of 3.1 per cent. The microhardness and adhesion of coatings also reached their maximum values of 64.8 Rockwell Hardness scale C and 60 MPa, respectively. XRD results indicated the transformation of Cr3C2 originating from Cr3C2-25NiCr source powder into Cr7C3 and Cr23C6 crystalline phases, due to the high temperature during spraying process. The undetectable Cr3C2 peaks indicating that this phase was remained in coating at very low concentrations. The potentiodynamic polarization and salt spray tests confirmed the highest corrosion resistance for the coating prepared by optimal spraying parameters. Originality/value The application of Cr3C2-NiCr cermet carbit coating for protection of steel from corrosion-erosion is very promising.

Corrosion behaviour of hot-dip Zn-Al-Mg coatings with different Al content

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Prabhat Kumar Rai ◽  
Dinesh Rout ◽  
D. Satish Kumar ◽  
Sanjay Sharma ◽  
G. Balachandran
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
Salt Spray ◽  
Protective Film ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Content Type ◽  
Al Content ◽  
Process Simulator

Purpose The purpose of the present study is to simulate the industrial hot-dip process of Zn-2.5Wt.%Mg-3 Wt.%Al and Zn-2.5 Wt.%Mg-9 Wt.%Al-0.15 Wt.%Si coatings and to study the effect of low and high Al variation on their microstructure, microhardness, adhesion and corrosion behaviour. Design/methodology/approach The hot-dip Zn-2.5 Mg-xAl coating simulation on steel substrate was carried out using a hot-dip process simulator. The microstructure of the coatings was characterized using a scanning electron microscope, energy dispersive spectroscopy and X-ray diffraction. The corrosion behaviour of the coatings was studied using a salt spray test in 5% NaCl solution as well as dynamic polarization in 3.5% NaCl solution. Findings Microhardness of the developed Zn-2.5 Mg-xAl coatings has been found to be approximately two times higher than that of the conventional galvanized coating. Zn-2.5 Mg-3Al coating has exhibited two times higher corrosion resistance as compared to that of Zn-2.5 Mg-9Al-0.15Si coating because of formation of more homogeneous and defect-free microstructure of the former. The MgZn2 phase has undergone preferential dissolution and provided Mg2+ ions to form a protective film. Originality/value The relative corrosion resistance of the two Zn–Al–Mg coatings with different Al content has been studied. The defect formed because of higher Al addition in the coating has been detected, and its effect on corrosion behaviour has been analysed.

Development of Corrosion Resistance Coating for AISI 410 Grade Steel

2015 ◽  
Vol 813-814 ◽  
pp. 135-139 ◽  
Author(s):  
K.G. Girisha ◽  
R. Rakesh ◽  
C. Durga Prasad ◽  
K.V. Sreenivas Rao
Keyword(s):  
Corrosion Resistance ◽  
Plasma Spray ◽  
Corrosion Behaviour ◽  
Steel Substrate ◽  
Salt Spray ◽  
Research Work ◽  
Optical Microscope ◽  
Air Plasma ◽  
Spray Process ◽  
Plasma Spray Process

In this present research work, corrosion behaviour of grit blasted AISI 410 steel substrate coated with NiCr/Al2O3,NiCr/ZrO2 particles was investigated using salt spray test as per ASTM B117. Coatings were prepared using air Plasma spray process. Nickel chromium was used as bond coat for obtaining good fastening between the base metal and coated particles. The microstructures of the coated and un-coated specimens were characterized using scanning electron microscope and optical microscope. Distribution coated particle was found uniform throughout the steel substrate was revealed from SEM microphotographs. The obtained results shows significant improvement in corrosion resistance and micro hardness for NiCr/Al2O3 and NiCr/ZrO2 coating deposited on steel by plasma spray process than the as sprayed base steel substrates.

Effect of rare earth lanthanum-cerium doping on corrosion behavior of zinc-aluminum-magnesium hot-dip galvanizing coatings used for transmission towers

2018 ◽  
Vol 65 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Yu Han ◽  
Yanqiu Xia ◽  
Xin Chen ◽  
Liang Sun ◽  
Dongyu Liu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Rare Earths ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Salt Spray ◽  
X Ray Diffraction ◽  
Copper Strip ◽  
Cross Sectional ◽  
Content Type ◽  
Transmission Towers

Purpose The purpose of this study is to improve the corrosion resistance of the transmission towers by Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La) and cerium (Ce) (denoted as Zn-Al-Mg-Re) in Q345 steel. Design/methodology/approach The phase structure of Zn-Al-Mg-Re composite coatings has been determined by X-ray diffraction, whereas their surface morphology and cross-sectional microstructure as well as cross-sectional elemental composition have been analyzed by scanning electron microscopy and energy-dispersive spectrometry. Moreover, the corrosion resistance of Zn-Al-Mg-Re composite coatings has been evaluated by acetic acid accelerated salt spray test of copper strip. Findings Experimental results show that doping with La and Ce favors to tune the composition (along with the generation of new phase, such as LaAl3 or Al11Ce3) and refine the microstructure of Zn-Al-Mg galvanizing coatings, thereby significantly improving the corrosion resistance of the coatings. Particularly, Zn-Al-Mg-Re with 0.15% (mass fraction) La exhibits the best corrosion resistance among the tested galvanizing coatings. Originality/Value Zinc-aluminum-magnesium (Zn-Al-Mg) coatings doped with rare earths lanthanum (La) and cerium (Ce) (denoted as Zn-Al-Mg-Re) have been prepared on Q345 steel substrate by hot-dip galvanizing so as to improve the corrosion resistance of the transmission towers, and to understand the corrosion inhibition of the Zn-Al-Mg-Re coating.

Effect of narrow pulse width laser cleaning on corrosion resistance of A5083-H111 aluminum alloy

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Feisen Wang ◽  
Sifei Ai ◽  
Qian Wang ◽  
Yinfen Cheng ◽  
Haiqi Huang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Surface Morphology ◽  
Elemental Composition ◽  
Pulse Width ◽  
Salt Spray ◽  
Laser Cleaning ◽  
Elemental Distribution ◽  
Content Type ◽  
Poor Area

Purpose The purpose of this paper is to promote the corrosion resistance of the 5083-111H aluminum alloy by laser cleaning. Design/methodology/approach Laser with 2 ns pulse width was adopted in this project and the corrosion resistance of cleaned samples was tested by copper-accelerated salt spray (CASS). The surface morphology, elemental composition and distribution were then characterized by SEM. Moreover, surface morphology, elemental composition and distribution were also tested. Findings Results suggested a higher corrosion resistance was successfully obtained by laser cleaning. Compared with samples cleaned by 2000 grit sandpaper, mechanical cleaning resulted in a 53% larger height difference between the peak and valley. The content of the oxygen is 8.85% on the surface cleaned mechanically and the distribution is dependent on the distribution of aluminum whereas that of the laser cleaning sample is 24.41% and the distribution existed even in the Al-poor area. Originality/value In this project, the 2-ns laser cleaning was proved to have the capability to remove the oxide layer on the aluminum alloy surface while retaining an excellent corrosion resistance and smooth surface. Meanwhile, a thorough elemental distribution and smaller grain size lead to a smaller difference in elemental concentration. This retards the diffusion of oxygen into the substrate and hence increases the corrosion resistance of the surface.

Effects of mass ratios on salt spray corrosion and electrochemical corrosion behaviors of laser cladded Cr–Ni coatings

2019 ◽  
Vol 66 (3) ◽  
pp. 352-359
Author(s):  
Li Jiahong ◽  
Kong Dejun
Keyword(s):  
Corrosion Resistance ◽  
Laser Cladding ◽  
Salt Spray ◽  
Electrochemical Corrosion ◽  
Corrosion Mechanism ◽  
H13 Steel ◽  
Content Type ◽  
Salt Spray Corrosion ◽  
Electrochemical Tests ◽  
Mass Ratios

Purpose The purpose of this paper is to improve the salt spray corrosion and electrochemical corrosion performances of H13 hot work mould steel, Cr–Ni coatings with the different Cr and Ni mass ratios are fabricated using a laser cladding (LC), which provides an experimental basis for the surface modification treatment of H13 steel. Design/methodology/approach Cr–Ni coatings with the different Cr and Ni mass ratios were firstly fabricated on H13 hot work mould steel using a laser cladding (LC). The salt spray corrosion (SSC) and electrochemical corrosion performances of Cr–Ni coatings in 3.5 Wt.% NaCl solution were investigated to analyze the corrosion mechanism, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed. Findings The laser cladded Cr–Ni coatings with the different Cr and Ni mass ratios are composed of Cr–Ni compounds, which are metallurgically combined with the substrate. The SSC resistance of Cr–Ni coating with the Cr and Ni mass ratios of 24:76 is the highest. The electrochemical corrosion resistance of Cr–Ni coating with the Cr and Ni mass ratio of 24:76 is the best among the three kinds of coatings. Originality/value In this study, the corrosion resistance of laser cladded Cr–Ni coatings with the Cr and Ni mass ratios of 17: 83, 20: 80 and 24: 76 was first evaluated using salt spray corrosion (SSC) and electrochemical tests, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed.

Corrosion resistance of composite coating used for fastener protection

2019 ◽  
Vol 66 (5) ◽  
pp. 595-602
Author(s):  
Zhifeng Lin ◽  
Likun Xu ◽  
Xiangbo Li ◽  
Li Wang ◽  
Weimin Guo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Composite Coating ◽  
Marine Environment ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Diffusion Method ◽  
Economic Losses ◽  
Neutral Salt ◽  
Content Type

Purpose The purpose of this paper is to examine the performance of a fastener composite coating system, sherardized (SD) coating/zinc-aluminum (ZA) coating whether it has good performance in marine environment. Design/methodology/approach In this paper, SD coating was fabricated on fastener surface by solid-diffusion method. ZA coating was fabricated by thermal sintering method. Corrosion behaviours of the composite coating were investigated with potentiodynamic polarization curves, open circuit potential and electrochemical impedance spectroscopy methods. Findings Neutral salt spray (NSS) and deep sea exposure tests revealed that the composite coating had excellent corrosion resistance. Polarization curve tests showed that corrosion current density of the sample with composite coating was significantly decreased, indicating an effective corrosion protection of the composite coating. OCP measurement of the sample in NaCl solution demonstrated that the composite coating had the best cathodic protection effect. The good corrosion resistance of the composite coating was obtained by the synergy of SD and ZA coating. Practical implications SD/ZA coating can be used in marine environment to prolong the life of carbon steel fastener. Social implications SD/ZA composite coating can reduce the risk and accident caused by failed fastener, avoid huge economic losses. Originality/value A new kind of composite coating was explored to protect the carbon steel fastener in marine environment. And the composite coating has the long-term anti-corrosion performance both in simulated and marine environment test.

Appraisal on corrosion performances of CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold

2020 ◽  
Vol 67 (2) ◽  
pp. 150-157
Author(s):  
Kong Dejun ◽  
Li Jiahong
Keyword(s):  
Corrosion Resistance ◽  
Salt Spray ◽  
Test Chamber ◽  
Electrochemical Corrosion ◽  
Optical Microscope ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
H13 Steel ◽  
Content Type ◽  
Electrochemical Corrosion Resistance

Purpose The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel, which improved the corrosion resistance of H13 hot work mold. Design/methodology/approach CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings were fabricated on H13 hot work mold steel using a laser cladding and cathodic arc ion plating. The SSC and electrochemical performances of obtained coatings were investigated using a corrosion test chamber and electrochemical workstation, respectively. The corrosion morphologies, microstructure and phases were analyzed using an electron scanning microscope, optical microscope and X-ray diffraction, respectively, and the mechanisms of corrosion resistance were also discussed. Findings The CrNi coating is penetrated by corrosion media, producing the oxide of Fe3O4 on the coating surface; and the TiAlN coating is corroded to enter into the CrNi coating, forming the oxides of TiO and NiO, the mechanism is pitting corrosion, whereas the CrNi–Al2O3–TiO2 coating is not penetrated, with no oxides, showing the highest SSC resistance among the three kinds of coatings. The corrosion potential of CrNi coating, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings was –0.444, –0.481 and –0.334 V, respectively, and the corresponding polarization resistances were 3,074, 2,425 and 86,648 cm2, respectively. The electrochemical corrosion resistance of CrNi–Al2O3–TiO2 coating is the highest, which is enhanced by the additions of Al2O3 and TiO2. Originality/value The CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold were firstly evaluated by the SSC and electrochemical performances.

The Influence of Major Defects on the Properties of Continuous Galvanized Steel Sheet

2012 ◽  
Vol 445 ◽  
pp. 661-666 ◽  
Author(s):  
A. Azimi ◽  
F. Shahriari ◽  
F. Ashrafizadeh ◽  
M.R. Toroghinezhad ◽  
J. Jamshidi
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Tensile Test ◽  
Steel Sheet ◽  
Corrosion Behaviour ◽  
Salt Spray ◽  
Galvanized Steel ◽  
Tafel Polarization ◽  
Steel Sheets ◽  
Bare Spot

Production of defect-free galvanized steel sheet is considered a major concern for automotive and other critical applications; nevertheless, the occurrence of some defects in the coated sheets is unavoidable. In order to alleviate the problem, we need to know the extent to which the properties of a galvanized sheet are influenced by the presence of a given defect. In this investigation, specimens including any of the two major defects of continuously galvanized steel sheets were selected from a large number of coated samples. The defects, including furnace roll pimples and bare spots, were microstructurally characterized and their influence on corrosion behaviour and mechanical properties of the steel sheet was evaluated. Corrosion resistance was examined via standard salt spray test and Tafel polarization. Tensile test was employed as a measure of mechanical properties of the defective galvanized sheets. The results indicated that the presence of defects had little influence on the tensile properties of the samples, but considerably reduced their corrosion resistance. Based on the results of salt spray tests, pimples reduced corrosion resistance of galvanized sheets 23 % (50 hours) on average and bare spot defects caused reduction in corrosion resistance up to 39%.

Effects of potassium silicate on corrosion behavior of dacromet coating

2019 ◽  
Vol 66 (6) ◽  
pp. 819-826
Author(s):  
Khashayar Tabi ◽  
Mansour Farzam ◽  
Davood Zaarei
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Automobile Industry ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Corrosion Current ◽  
Potassium Silicate ◽  
Coated Steel ◽  
Content Type ◽  
New Information

Purpose Potassium silicate sealer was applied on solvent-cleaned, acid-pickled, dacromet-coated steel to improve its corrosion resistance. The purpose of this paper is to study the corrosion behavior of dacromet-coated steel. Design/methodology/approach Potassium silicate sealer was applied on solvent-cleaned, acid-pickled, dacromet-coated steel to improve its corrosion resistance. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and salt spray were carried out. SEM was used to study the morphological appearance of the surface. Findings The EIS behavior indicated that solvent-cleaned dacromet-coated steel sealed with potassium silicate showed that the corrosion current density was 2.664E − 5 A.cm2 which was reduced to 8.752E − 6 A.cm2 and the corrosion rate, which was 2.264E − 2 mm.year−1, was reduced to 7.438E − 3 mm.year−1 in NaCl 3.5 wt.per cent. EIS was used in NaCl 3.5 wt.%, and the Bode plot characteristics showed that the corrosion protection of solvent-cleaned, dacromet-coated steel was enhanced when sealed with potassium silicate. The EDS results of salt-sprayed, solvent-cleaned samples after 10 days indicated that the main corrosion products are composed of SiO2, ZnO and Al2O3. Research limitations/implications The detection of Li element in EDS was not possible because of the device limitation. Originality/value The current paper provides new information about the sealing properties of potassium silicate and its effects on the corrosion resistance of dacromet coating, which is widely used in many industries such as the automobile industry.

Corrosion Behaviour of Ti6Al4V and TiMo10Zr4 Alloys in the Ringer’s Solution: Effect of pH and Plastic Strain

2015 ◽  
Vol 227 ◽  
pp. 435-438 ◽  
Author(s):  
Joanna Loch ◽  
Alicja Łukaszczyk ◽  
Vincent Vignal ◽  
Halina Krawiec
Keyword(s):  
Corrosion Resistance ◽  
Plastic Strain ◽  
Titanium Alloys ◽  
Passive Film ◽  
Current Density ◽  
Potentiodynamic Polarization ◽  
Corrosion Behaviour ◽  
Ringer’S Solution ◽  
Ph Values

The corrosion behaviour of titanium alloys is not well understood – especially the role of the microstructure and plastic strain. In this paper, the influence of the microstructure and plastic strain on the corrosion resistance of TiMo10Zr4 and Ti6Al4V alloys was studied in the Ringer’s solution at 37 °C. Measurements were performed for different pH values and in aerated and de-aerated solutions using potentiodynamic polarization techniques. Results obtained on the two alloys were compared. It was shown that in the absence of plastic strain TiMo10Zr4 shows better corrosion resistance than Ti6Al4V (especially for pH = 8). By contrast, the current density in the passive range measured after 8% plastic strain was greater on TiMo10Zr4 than on Ti6Al4V, indicating that the passive film on TiMo10Zr4 is less protective than that formed on Ti6Al4V.

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