Influence of Rare Earth on Hot-Dipped 55%Al-Zn Alloy Coating

2013 ◽  
Vol 774-776 ◽  
pp. 1132-1136 ◽  
Author(s):  
Tai Xiong Guo ◽  
Xue Qiang Dong ◽  
Shu Hui Deng ◽  
Feng Li ◽  
Yi Lin Zhou
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Simulation Experiment ◽  
Steel Substrate ◽  
Intermetallic Layer ◽  
Alloy Coating ◽  
Al Alloy ◽  
Zinc Dross ◽  
Zn Alloy ◽  
The Rare Earth

Simulation experiment was done to investigate the effects of rare earth on hot-dipped Zn-55%Al alloy coating. The results show that the rare earth has little effect on the zinc dross and its burning loss is about 10%. The microstructure of coating is similar to that of solidification bath, and which is made up of phases of rich aluminum, rich zinc, rich silicon and rare earth, and intermetallic layer of Al-Zn-Fe-Si. The rare earth phase is needle or rod, and mainly distributed inside rich zinc phase and on the interface between the coating and steel substrate. The rare earth has no obvious influence on coating grain and spangle size. The appropriate addition of rare earth would be helpful to improve the coating bending formability and corrosion resistance.

Corrosion Resistance of Rare Earth Modified Chromizing Coating on P110 Oil Casing Tube Steel by Pack Cementation

2009 ◽  
Vol 79-82 ◽  
pp. 1075-1078
Author(s):  
Nai Ming Lin ◽  
Fa Qin Xie ◽  
Tao Zhong ◽  
Xiang Qing Wu ◽  
Wei Tian
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Steel Substrate ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Pack Cementation ◽  
Tube Steel ◽  
X Ray ◽  
Immersion Corrosion ◽  
P110 Steel

The rare earth (RE) modified chromizing coating was obtained on P110 oil casing tube steel (P110 steel) substrate by means of pack cementation technique to enhance the resistance against corrosion of P110 steel. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX) and X-ray diffraction (XRD) were employed to research microstructure, composition distribution and phase constitution of the chromizing coating. The effect of minor addition of RE on the microstructure of chromizing was discussed. Corrosion resistance of chromizing coating was investigated and compared with that of bare P110 steel via electrochemical corrosion and immersion corrosion in simulated oilfield brine solution, respectively. The results showed that a uniform, continuous and compact coating was formed on P110 steel. The coating with RE addition was more compact than that of the coating added no RE, and a small amount of RE addition could promote the chromizing procedure notably. From SEM and EDX investigation, it had been confirmed that the coating was composed of two different layers, an out layer and an inner layer; the coating mainly contains Fe and Cr; the concentration of Cr decreased as the distance from the surface increased, yet Fe presented the inverse trend. XRD analysis indicated the coating was built up by (Cr, Fe)23C6 referring to the out layer, (Cr, Fe)7C3, Cr7C3 and α-(Cr, Fe) corresponding to the inner layer. Electrochemical corrosion consequence was obtained as follows: the self-corroding electric potential of chromizing coating was higher, and the corrosion current density was lower than that of bare P110 steel, which revealed that chromizing coating had better anti-corrosion performance; immersion corrosion results demonstrated the mass loss of chromized P110 steel was lower, and this meant that chromizing coating had a better corrosion resistance than that of bare P110 steel on the experimental condition. A compact (Cr, Fe)xCy coating can be fabricated by pack cementation technique. As a result of minor RE addition, microstructure and corrosion resistance of the chromizing coating are improved obviously.

scholarly journals Effect of Rare Earth Element La on Corrosion Resistance of Powder Zinc Coating: Experiment and First Principle Calculation

2021 ◽  
Vol 2101 (1) ◽  
pp. 012058
Author(s):  
J P Xin ◽  
S Y Zhang ◽  
S P Hu
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Earth Element ◽  
Salt Spray ◽  
Zinc Coating ◽  
Chemical Heat Treatment ◽  
Chemical Heat ◽  
The Rare Earth

Abstract Using a combination of first-principles calculations and experimental studies to study the effect of La on the corrosion resistance of Powder sherardizing layer in metal structures. Compared to other sherardizing rare earth elements (Re), La has better adsorption with the iron matrix and has the lowest binding energy on the adsorption surface (111) of the Fe matrix. Therefore, the rare earth element La is added to the powder sherardizing process for the rare earth chemical heat treatment to reduce the defects of the powder sherardizing faults formed, improve the surface uniformity and the quality of the permeation layer. On the basis of calculation, La element was added in the process of powder sherardizing, and the corrosion performance of the formed powder galvanizing layer was studied. After alternating salt spray experiments, the degree of corrosion of the layer is relatively small and the corrosion products are predominantly layered and spherical. Electrochemical tests of the layer show that the corrosion resistance of the layer after the rare earth chemical heat treatment has improved.

Research of Anti-Corrosion of Armour Steel in Surface Chromate Conversion Coating

2013 ◽  
Vol 734-737 ◽  
pp. 2332-2337
Author(s):  
Rui Hua Guo ◽  
Fang Sheng Liu ◽  
Lin Min Wang
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Electrochemical Method ◽  
Electrochemical Corrosion ◽  
Conversion Coating ◽  
Chromate Conversion Coating ◽  
Conversion Time ◽  
Armour Steel ◽  
The Rare Earth

This article by orthogonal experimental method to determine the composition of chromate conversion and use of electrochemical method of electrochemical corrosion of the film discussed the substrate in different components, content, time and pH of chromate conversion coating of corrosion resistance. Orthogonal to determine the best experimental chromate conversion solution by adding the rare earth element cerium and lanthanum salt, and discuss the effects of rare earth elements cerium and lanthanum chromate conversion film on the anti-corrosion. The results show that in CrO3 5.4 g/L, NaF 0.5 g/L, K3Fe (CN)6 0.5 g/L, pH 1, conversion time is three minutes, there is a better corrosion resistance. The rare earth elements in a chromate conversion solution, La2(CO3)3 to 0.2 g/L chromate conversion coating of the anti-corrosion better.

Influence of Cold Rolling Process on Mini Spangle Formation of 55%Al-Zn Alloy Coating Steel Sheet

2018 ◽  
Vol 936 ◽  
pp. 171-177
Author(s):  
Tai Xiong Guo ◽  
Xue Qiang Dong ◽  
Chang Rong Ran
Keyword(s):  
Cold Rolling ◽  
Steel Sheet ◽  
Steel Substrate ◽  
Steel Strip ◽  
Alloy Coating ◽  
Compound Layer ◽  
Rolling Process ◽  
Intermetallic Compound Layer ◽  
Rolling Oil ◽  
Zn Alloy

According to that mini spangle is the most common defect affecting the appearance quality of hot-dip 55%Al-Zn alloy coated steel sheet, industrial experiments and statistical analysis were done to investigate the influence of cold rolling process on the formation of mini spangle. The results show that, with the decrease of rolling oil concentration, the increase of rolling time, and the increase of rolling pass, the probability of mini-spangle formation increases. Due to the different equipment conditions, the probability of mini-spangle formation on the upper and lower surfaces of steel strip is different. The reason of mini-spangle formation lies in the presence of carboxylates (R-COO-Fe) result from the residual emulsion on the surface of cold rolled steel strip. The carboxylates may interfere with the interfacial reaction between the steel substrate and Al-Zn bath, and result in more convex Fe5Si2Al20 phases formed on the surface of intermetallic compound layer. The Fe5Si2Al20 phases may provide more heterogeneous nucleation sites for the formation of Al-rich dendrites and lead to the formation of mini spangle.

Effect of Doping of Nanoparticles on the Properties of Zn-Ni Composite Coatings

2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Corrosion Performance ◽  
X Ray ◽  
Ni Alloy

The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.

The Corrosion Mechanism of Cu-Containing Weathering Steel in a Cyclic Dry-Wet Condition

2009 ◽  
Vol 79-82 ◽  
pp. 957-960 ◽  
Author(s):  
Li Jie Yue ◽  
Wei Gong Chen
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Corrosion Product ◽  
Resistance Mechanism ◽  
Electrochemical Corrosion ◽  
Weathering Steel ◽  
Corrosion Mechanism ◽  
Steel Matrix ◽  
Rust Layer ◽  
The Rare Earth

The weather resistance of 10CuPRE、10CuP and Q235 steels were studied by dry-wet cyclic immersion test. The corrosion resistance mechanism of rare earth Cu-containing weathering steel was studied through electrochemical polarization test, scanning electron microscope(SEM) and X ray diffraction(XRD). The results show the small and spherical rare earth oxysulfides replace the elongated MnS inclusions in the rare earth weathering steel. Less and fewer rare earth oxysulfides heavily decrease pitting susceptibility and rate of pit propagation. So the electrochemical corrosion of microarea in the steel matrix is weakened after rare earth was added in the Cu-containing weathering steel. The inner rust layer of rare earth weathering steel is more compact and uniform than that of weathering steel without rare earth. The main corrosion product on the rare earth weathering steel is α-FeOOH. The formation of the steady corrosion product is promoted by rare earth, which result in that the protective property of the inner rust layer on weathering steels is enhanced. As a result, the corrosion resistance of Cu-containing weathering steel is improved by rare earth elements.

Study on the Properties of the Laser Cladded Cobalt-Based Alloy Coating on T10 Tool Steel

2011 ◽  
Vol 464 ◽  
pp. 686-689
Author(s):  
Cheng Yun Cui ◽  
Xi Gui Cui ◽  
Yong Kong Zhang ◽  
Qian Zhao ◽  
Jin Zhong Lu
Keyword(s):  
Corrosion Resistance ◽  
Tool Steel ◽  
Co2 Laser ◽  
Steel Substrate ◽  
Cryogenic Treatment ◽  
Alloy Coating ◽  
Reinforced Composite ◽  
Maximum Value ◽  
Obvious Change ◽  
Continuous Co2 Laser

Co-based alloy coating was cladded on T10 tool steel by the powder feeding and continuous CO2 laser. The results showed that compared to the unreinforced T10 tool steel substrate, the microhardness of the Co-based reinforced composite was significantly enhanced and the maximum value was existed in the middle of the cladding coating. The corrosion resistance of the cladding coating was also improved. After cryogenic treatment, there is no obvious change for the structure of the cladding coating while the phase is transformed, leading to an increase in the microhardness of the cladding coating.

scholarly journals Minor Special Issue on Corrosion. Evaluation of Corrosion Resistance for Zn-5%Al Alloy Coating on Steel Structures.

1993 ◽  
Vol 42 (479) ◽  
pp. 941-947
Author(s):  
Yoshihiko TAKANO ◽  
Tatsumi IZEKI ◽  
Tetsuya NAKADA ◽  
Koshi TAKADA ◽  
Masamichi YAMASHITA
Keyword(s):  
Corrosion Resistance ◽  
Steel Structures ◽  
Alloy Coating ◽  
Al Alloy ◽  
Special Issue ◽  
Corrosion Evaluation

scholarly journals Study on growth factors of intermetallic layer within hot-dipped 25% Al-Zn alloy coating on steel

2001 ◽  
Vol 24 (3) ◽  
pp. 301-304 ◽  
Author(s):  
Yan Li ◽  
Ying Ma ◽  
Baorong Hou ◽  
Falun Feng ◽  
Xujun Wei
Keyword(s):  
Growth Factors ◽  
Intermetallic Layer ◽  
Alloy Coating ◽  
Zn Alloy

scholarly journals Microstructure and Corrosion Behavior of (CoCrFeNi)95Nb5 High-Entropy Alloy Coating Fabricated by Plasma Spraying

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 694 ◽  
Author(s):  
Wenrui Wang ◽  
Wu Qi ◽  
Lu Xie ◽  
Xiao Yang ◽  
Jiangtao Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Steel Substrate ◽  
Alloy Coating ◽  
High Entropy Alloy ◽  
Pitting Potential ◽  
Q235 Steel ◽  
High Entropy ◽  
Passivation Film ◽  
Elemental Segregation

In this paper, the (CoCrFeNi)95Nb5 high-entropy alloy (HEA) coating with a thickness of 500 μm on Q235 steel substrate was fabricated by plasma spraying. The microscopic results showed that a new Laves phase is formed in the (CoCrFeNi)95Nb5 HEA coating compared to the HEA powder, and elemental segregation occurs between the dendrites and the interdendrites of the coating, while the interdendritic phase enriches with the Cr and Nb. The phase composition change and elemental segregation behavior were mainly due to the faster cooling rate of the plasma spraying technique. At the junction of the coating and the substrate, the HEA coating bonded well to the substrate; in addition, the width of transition zone was merely 2 μm. The microhardness of the (CoCrFeNi)95Nb5 HEA coating was 321 HV0.5, which is significantly higher than that of the substrate. In terms of corrosion resistance, the (CoCrFeNi)95Nb5 HEA coating has good corrosion resistance in NaCl solution. Although the corrosion form was pitting corrosion, the pitting potential of the (CoCrFeNi)95Nb5 HEA coating was significantly higher than that of other coatings, which was mainly because of the dense passivation film formed by Cr and Nb on the surface of the coating. Once the passivation film was destroyed by Cl−, the selective corrosion occurred on the surface of the (CoCrFeNi)95Nb5 HEA coating. In summary, the (CoCrFeNi)95Nb5 HEA coating prepared by plasma spraying technology can significantly improve the corrosion resistance and mechanical properties of the Q235 steel substrate.

Sign in / Sign up

Export Citation Format

Share Document