Corrosion Behavior of Cold-Spray Aluminum Coating in Marine Environment

2010 ◽  
Vol 160-162 ◽  
pp. 364-368
Author(s):  
Qing Jun Zhu ◽  
Kai Wang ◽  
Xin Hong Wang
Keyword(s):  
Cold Spray ◽  
Marine Environment ◽  
Aluminum Coating ◽  
Corrosion Morphology ◽  
Aluminum Coatings ◽  
Mild Carbon Steel ◽  
Dissolution Zone ◽  
Bond Zone ◽  
Corrosion Behaviors ◽  
Scanning Electron

Aluminum coatings were prepared by cold spray on mild carbon steel Q235. Scanning electron microscopy shows that the bond zone has good bonding between the substrate and the coating and the coatings consist of interlocked particles. The corrosion behaviors of the coatings in marine environment were studied by electrochemical methods. Free corrosion potentials of aluminum coatings are much lower than that of Q235. Potentiodynamic polarization measurements show that the curves of aluminum coatings have activity anodic dissolution zone, passivation zone and super-passivation zone. Corrosion morphology and energy dispersive spectrometers show that Cl- can penetrate into the coating and some of the substrate has been corroded. Corrosion only can happen on the coating surface and specific deeper sites, where Cl- can penetrate through pores. Cold spray aluminum coatings can protect the substrate from corrosion in marine environment.

Microstructure and Anti-Corrosion Properties of Arc-Sprayed Aluminum Coating in Splash Zone

2011 ◽  
Vol 199-200 ◽  
pp. 1949-1953
Author(s):  
Qing Jun Zhu ◽  
Kai Wang
Keyword(s):  
Aluminum Coating ◽  
Splash Zone ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Aluminum Coatings ◽  
Arc Spray ◽  
Mild Carbon Steel ◽  
Dissolution Zone ◽  
Corrosion Behaviors ◽  
Al Coating

Aluminum coatings were developed by arc spray on mild carbon steel Q235. Scanning electron microscopy detection shows that the coatings have good bonding with the substrate and have low porosity. The corrosion behaviors of the coatings in splash zone were studied. The results show that free corrosion potentials of aluminum coatings are much lower than that of Q235. Potentiodynamic polarization measurements reveal that the curves of aluminum coatings have activity anodic dissolution zone, passivation zone and super-passivation zone. Corrosion morphology and energy dispersive spectrometers show that Cl- can penetrate into the coatings and some of the substrate has been corroded. The arc spray Al-coating develops a film of corrosion products on the coating surface, which tend to seal the pores in the coatings. Arc spray aluminum coatings can protect the substrate from corrosion in splash zone.

Investigation of the Splat Deposition Behavior onto a Composite Coating in Cold Spray

2018 ◽  
Vol 941 ◽  
pp. 1639-1644
Author(s):  
Xin Chu ◽  
Phuong Vo ◽  
Stephen Yue
Keyword(s):  
Electron Microscope ◽  
Composite Coating ◽  
Cold Spray ◽  
Spray Deposition ◽  
Cold Spraying ◽  
Single Component ◽  
Optical Profilometry ◽  
Deposition Behavior ◽  
Polished Substrate ◽  
Scanning Electron

The splat test is usually generated by low feed rate cold spraying of particles onto an as-polished substrate and it can be considered as a monolayer coating deposition. In this study, in order to investigate cold spray deposition mechanisms, Fe splats were sprayed onto the cold-sprayed single component 316L, Fe, and a composite 90Fe coatings. Results showed that although there is only 3.6 vol.% of 316L in the composite 90Fe coating, Fe splats exhibit a much better deposition behavior onto the 90Fe as compared with the single component Fe coating. To explain this observation, Fe splat samples were characterized using the scanning electron microscope (SEM), optical profilometry, splat adhesion tests, and splat nanoindentation. Finally, a preliminary explanation towards the Fe splat deposition behavior onto the composite coating was drawn.

Corrosion Behaviors of Mg-7Gd-5Y-1Nd-0.5Zr Alloys in CO2 Atmosphere under Different Relative Humidity

2014 ◽  
Vol 900 ◽  
pp. 39-42
Author(s):  
Quan Tong Jiang ◽  
Xing Gang Li ◽  
Yong Jun Li ◽  
Ming Long Ma ◽  
Guo Liang Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Relative Humidity ◽  
Influence Factors ◽  
Corrosion Morphology ◽  
Corrosion Rates ◽  
Corrosion Behaviors ◽  
Peak Aged ◽  
Residual Mechanical Properties ◽  
Loss Rates

The corrosion behaviors of peak-aged Mg-7Gd-5Y-1Nd-0.5Zr alloys in CO2atmosphere under different relative humidity were investigated by OM, SEM. The weight loss rates, corrosion morphology and residual mechanical properties were also analyzed. The corrosion rates of specimens in CO2atmosphere at 70% relative humidity were highest than others. Relevancy of the influence factors included relative humidity and concentration of CO2were researched. The results show that relative humidity and concentration of CO2in the environment both played an important role in corrosion behaviors.

Corrosion inhibition of N80 steel in 10% HCl + 8% HBF4solution

2019 ◽  
Vol 66 (1) ◽  
pp. 1-10
Author(s):  
Juan Du ◽  
Yuning He ◽  
Pingli Liu ◽  
Yigang Liu ◽  
Xianghai Meng ◽  
...  
Keyword(s):  
Corrosion Inhibition ◽  
Design Methodology ◽  
X Ray Diffraction ◽  
Corrosion Morphology ◽  
Content Type ◽  
X Ray ◽  
N80 Steel ◽  
Corrosion Reaction ◽  
Hydrolysis Of ◽  
Scanning Electron

PurposeThis paper aims to analyze the corrosion and corrosion inhibition of N80 in 10 per cent HCl + 8 per cent fluoroboric acid (HBF4) solution for acidizing operation.Design/methodology/approachThe corrosion rate, kinetic parameters (Ea, A) and thermodynamic parameters (ΔH, ΔS) of N80 steel in fresh acid and spent acid, 10 per cent HCl + 8 per cent HBF4, 10 per cent HCl and 8 per cent HBF4solutions were calculated through immersion tests. The corrosion and inhibition properties were studied through X-ray diffraction and electrochemical measurements. The corrosion morphology of the corrosion product was examined by scanning electron microscopy (SEM).FindingsThe results demonstrated that the spent acid was the main cause of acidification corrosion, and the HBF4would cause serious corrosion to N80 steel. The results showed that the N80 steel was more seriously corroded in the spent acid than in fresh acid, and the hydrolysis of HBF4accelerates the dissolution process of N80 steel anode to control the corrosion reaction. The results showed that the acidification will definitely cause serious corrosion to the oil tube; therefore, necessary anti-corrosion measures must be taken in the acidification process.Originality/valueThe results showed that acidizing the formation with 10 per cent HCl + 8 per cent HBF4will definitely cause serious corrosion to the oil tube, especially when the spent acid flows back. Therefore, necessary anti-corrosion measures must be taken in the acidification process, especially in the spent acid flowback stage.

Corrosion of the Materials in Sulfuric Acid

2008 ◽  
Author(s):  
Hong Pyo Kim ◽  
Dong-Jin Kim ◽  
Hyuk Chul Kwon ◽  
Ji Yeon Park ◽  
Yong Wan Kim
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Hydrogen Production ◽  
Immersion Time ◽  
Cross Sectional ◽  
Corrosion Morphology ◽  
Nuclear Heat ◽  
Corrosion Behaviors ◽  
Materials Used ◽  
Surface Morphologies

The program for hydrogen production with high temperature nuclear heat has been launched in Korea since 2004. Iodine sulfur (IS) process is one of the promising processes for a hydrogen production because it does not generate a carbon dioxide and massive hydrogen production may be possible. However, the highly corrosive environment of the process is barrier to the application in the industry. Therefore, corrosion behaviors of various materials were evaluated in sulfuric acid to select appropriate materials compatible with the IS process. The materials used in this work were Ni base alloys, Fe-Si alloys, Ta, Au, Pt, Zr, SiC and so on. The test environments were boiling 50wt% sulfuric acid without/with HI as an impurity and 98wt% sulfuric acid. The surface morphologies and cross sectional areas of the corroded materials were examined by using SEM equipped with EDS. From the results of the weight loss and potentiodynamic experiments, it was found that a Si enriched oxide is attributable to a corrosion resistance for materials including Si in boiling 98wt% sulfuric acid. Moreover the passive Si enriched film thickness increased with the immersion time leading to an enhancement of the corrosion resistance. Corrosion behaviours of the material tested are discussed in terms of the chemical composition of the materials, a corrosion morphology and the surface layer’s composition.

scholarly journals Effect of Cu on the Fracture and Exfoliation Corrosion Behavior of Al-Zn-Mg-xCu Alloy

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1048 ◽  
Author(s):  
Huibin Jiao ◽  
Kanghua Chen ◽  
Songyi Chen ◽  
Zhen Yang ◽  
Peng Xie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Exfoliation Corrosion ◽  
Cu Content ◽  
Short Transverse ◽  
Transmission Electron ◽  
Corrosion Behaviors ◽  
Mechanical Tensile ◽  
Scanning Electron ◽  
Better Than

In the present work, the influence of Cu content on microstructure, mechanical properties and exfoliation corrosion behaviors of Al-Zn-Mg-xCu alloy extrusions has been investigated in longitudinal-transverse (L-T) and short-longitudinal (S-L) directions by means of mechanical tensile and exfoliation corrosion testing combined with optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that a higher Cu content significantly decreased the fracture toughness and ductility of the alloy in S-L direction compared with L-T direction. Concomitant with the increase in Cu content, a transition in fracture mode was observed from transgranular dimpled rupture to intergranular rupture in S-L direction. Moreover, the exfoliation corrosion (EXCO) resistance of the alloy decreased as the Cu content increased and the exfoliation corrosion resistance of the alloy in short-transverse (S-T) direction was better than that of L-T direction. These results were mainly associated with the large number of coarse intermetallics caused by high Cu content in the L-T direction of alloy.

Corrosion behaviors of X70 steel under direct current interference

2019 ◽  
Vol 66 (3) ◽  
pp. 307-316 ◽  
Author(s):  
Jun Wang ◽  
Zili Li ◽  
Gan Cui ◽  
JianGuo Liu ◽  
Chuanping Kong ◽  
...  
Keyword(s):  
Weight Loss ◽  
Corrosion Rate ◽  
Soil Solution ◽  
Direct Current ◽  
Polarization Curves ◽  
Solution Ph ◽  
Corrosion Morphology ◽  
Content Type ◽  
Tafel Polarization ◽  
Corrosion Behaviors

Purpose The purpose of this paper is to study the corrosion behaviors of X70 steel under direct current (DC) interference at 0-1,200 A/m2 in simulated soil solution. Design/methodology/approach The Tafel polarization curves of X70 steel under DC interference were tested using electrochemical method, the corrosion rate was calculated using weight-loss method and the change in steel surface was analyzed by optical microscopy. Findings The results showed that E-I polarization curves under 200-1,200 A/m2 interference were linear; with an increase in the DC density, the corrosion potential of X70 steel shifted positively, solution pH after the weight-loss tests increased and corrosion rate increased linearly. A mathematical relationship between polarization resistance Rp and current density was established. Corrosion morphology indicated that pitting corrosion and crevice corrosion occurred on the X70 steel under DC interference in simulated soil solution. Originality/value All tests were conducted at a relative higher DC density (200-1,200 A/m2). The linear fitting method is proposed to fit data of Tafel polarization curves under DC interference. This study provides guidelines for safe operation of X70 steel pipelines.

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