Effect of Vanadium and Niobium on Abrasive Behaviour of Arc Sprayed 4Cr13 Coatings

2013 ◽  
Vol 395-396 ◽  
pp. 712-717 ◽  
Author(s):  
Yu Deng ◽  
Sheng Fu Yu ◽  
Ning Yan ◽  
Shu Le Xing ◽  
Lin Bing Huang

4Cr13 martensitic stainless steel coatings with different amount of V/Nb were prepared on the surface of the Q235 low-carbon steel by high velocity arc spraying (HVAS). The microstructure and properties of the coatings were characterized and tested by scanning electron microscope (SEM), X-ray diffraction (XRD), optical microscope, microhardness tester and wear tester. And the wear mechanisms of the coatings have been studied. The results showed that optimal percentage of V/Nb could improve performance of the coatings. The coatings had good forming properties, uniformity of microstructure and compact structure.The highest value of adhesion strength was up to about 36.80 Mpa. The hard particles could incease the hardness and wear resistanc of the coatings.The average microhardness was about 523 HV0.1, higher than that of 4Cr13 coatings, and the abrasive wear resiatance was enhanced because of the added elements V and Nb. Key words: alloying coatings; 4Cr13; V/Nb; high velocity arc spraying (HVAS); abrasive behaviour

2011 ◽  
Vol 189-193 ◽  
pp. 523-527
Author(s):  
Zhi Hua He ◽  
Yu Ping Wu ◽  
Hong Bin Sun ◽  
Yuan Zheng ◽  
Yu Dong ◽  
...  

In order to increase cavitation erosion resistance of fluid machinery, an iron-based coating was prepared by high velocity arc spraying (HVAS) on the surface of 1Cr18Ni9Ti stainless steel. The microstructure and performance were investigated respectively by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), Vickers hardness and vibratory cavitation apparatus. The results indicated that the coating had the higher hardness (8.67GPa) and the finer structure than ZG230-450 (1.86GPa) used actual in water conservancy. Compared with ZG230-450, cavitation erosion resistance of the coating was better, and the coating presented flakiness stripping mode. The results indicated that the HVAS is a promising method to prepare the cavitation resistance coating.


Author(s):  
J.A. Hearley ◽  
J.A. Little ◽  
A.J. Sturgeon

Abstract A reaction-formed NiAI intermetallic compound (IMC) powder has been deposited as a coating onto low carbon steel test coupons by the High Velocity Oxy-Fuel (HVOF) process using both gaseous and liquid fuels. The microstructure of this coating has been examined using scanning electron microscopy and x-ray diffraction and was found to depend on spraying conditions. Oxidation tests on the coating in air, between the temperatures of 800°C-1200°C, revealed that an a-alumina (Al2O3) scale formed on the coating's surface. At 1200°C, a nickel spinel (NiO/NiAl2O4) and haematite (Fe2O3) phases were observed. Diffusion studies were performed to calculate an activation energy for iron ion diffusion in NiAl.


2011 ◽  
Vol 179-180 ◽  
pp. 253-256
Author(s):  
Hao Chen ◽  
Jian Gao Yang ◽  
Mi Song Chen

The Fe-based composite coatings were formed by plasma jet surface metallurgy using Fe, C, W, Cr and Al alloy powders on the low carbon steel. The morphology, microstructure, interface structure and the distribution of the in situ particles in the coatings were observed with optical microscope, scanning electron microscope and x-ray diffraction analysis. The results show that metallurgical bonding is obtained between coating and substrate, and the microstructure of coatings is mainly composed of γ-Fe, (Fe,Cr,W,Nb)7C3 and AlFe particles which are synthesized in stiu, are dispersivly distributed in the coatings. The micro-hardness gradually increased from bottom to the top of the coating, the maximum is 986 Hv0.1, about 4 times larger than that of the steel substrate.


Author(s):  
M. Prince ◽  
A. Justin Thanu ◽  
P. Gopalakrishnan

AbstractIn this investigation, AISI 1020 low carbon steel has been selected as the base material. The Ni based super alloy powder NiCrBSiFeC was sprayed on the base material using high velocity oxy-fuel spraying (HVOF) technique. The thickness of the coating was approximately 0.5 mm (500 μm). The coating was characterized using optical microscopy, Vickers microhardness testing, X-ray diffraction technique and scanning electron microscopy. Dry sliding wear tests were carried out at 3 m


2018 ◽  
Vol 21 (1) ◽  
pp. 82
Author(s):  
Mofeed A. Jaleel ◽  
Eilaf Z. Gurji

The Electrodeposition process has been used to prepare Nickel-Tungsten alloys on low carbon steel substrate by using ammonical citrate bath. The influence of deposition condition by variation of current density (0.04-0.2 A/cm2) and solution temperature (60-70 °C), on the microstructure was studied. The optical microscope and the scanning electron microscopy (SEM) were used to study the morphology of the deposit while the energy dispersive spectroscopy (EDS) was used to approximate the composition, in addition to X-Ray diffraction examination. The results show that the current efficiency has the major influence on the tungsten content in the alloys due to the formation of ternary complex which reflected into the properties of the deposit. Keywords: 


2011 ◽  
Vol 696 ◽  
pp. 170-175 ◽  
Author(s):  
Komsan Ngamkham ◽  
Satian Niltawach ◽  
Somrerk Chandra-ambhorn

Hot-rolled low carbon steel strips were produced using two different finishing temperatures at 910 and 820 °C in an industrial hot-rolling line. Mechanical adhesion of scale on the steel substrate at 40 mm from the edge was investigated by tensile test. It was found that the strain initiating the first spallation of scale produced at higher finishing temperature was lower. Spallation ratio which is a spalled area of scale divided by the total area of scale examined under an optical microscope was steeper when the scale was produced at higher finishing temperature. The lower values of strain initiating the first spallation and the higher values of spallation ratio of scale formed both at higher finishing temperature were due to higher thickness of that scale. Pickling behaviour of the hot-rolled steels was investigated by immersing the studied steels in a 10%v/v HCl solution at 80 °C. X-ray diffraction (XRD) peak of hematite relative to that of iron decreased with pickling time and approached zero during pickling periods from 3 to 10 s, while magnetite-and-iron ratio gradually decreased and tended to be zero at longer pickling time. This might indicate the existence of hematite as the outermost layer of scale and subscale containing magnetite as the inner part.


2021 ◽  
Vol 800 ◽  
pp. 140249
Author(s):  
Juan Macchi ◽  
Steve Gaudez ◽  
Guillaume Geandier ◽  
Julien Teixeira ◽  
Sabine Denis ◽  
...  

MRS Advances ◽  
2017 ◽  
Vol 2 (50) ◽  
pp. 2809-2817
Author(s):  
Daniel S. Huerta ◽  
E.D. García Bustos ◽  
D.V. Melo Máximo ◽  
M. Flores Martinez

ABSTRACTIn the present work the kinetic growth is analyzed for a hard coating applied on a low carbon steel AISI 8620. A thermochemical treatment of bored with dehydrated paste at temperatures of 900, 950 and 1000 °C with a residence time of 2, 4, 6 and 8 h. The morphology and types of borides formed on the surface of the steel were evaluated by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The layer formed has a size of 20 to 113 μm which will be dependent on the process temperature, the treatment time and the alloy elements of the substrate. Hardness of 1493-1852 HV are presented for treatment times and temperatures established in this study. The kinetics of growth were determined and analyzed using a mathematical model of diffusion, evaluating the penetration of the biphasic layer that is determined as a function of the time and temperature of the thermochemical treatment (TCT). The results show the increase in the growth constants (k) with respect to the bored temperatures. The activity energy (Q) of the material AISI 8620 was also obtained.


2009 ◽  
Vol 79-82 ◽  
pp. 1017-1020 ◽  
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Song Lian Bai ◽  
Zhou Hua Jiang

The corrosion behaviors of Al-Si-Cr-Cu bearing low carbon steel and a reference steel Q235 were tested in a cyclic dry/wet environment containing 0.01mol/L NaHSO3 in laboratory. Rust layers were observed by optical microscope (OM), scanning electron microscopy (SEM) and XRD. The electrochemical behaviors of the steels were studied on the polarization curves and electrochemical impedance spectroscopy (EIS). The results indicate that after 120h corrosion test, the annual corrosion rates of the designed steels reduce 42 % than Q235 at least. The corrosion products are generally iron oxyhydroxides and oxides such as FeOOH, γ-FeOOH, α-FeOOH, γ-Fe2O3, Fe3O4. The α-FeOOH possesses good stabilization mainly exits and can improve the corrosion resistance. There are the enrichments of Cu, Cr, Si and Al in the rust layer close to the matrix, which make the rust layer be more compact and protected. The corrosion currents of the two designed steels are lower than that of Q235, the corrosion potentials are higher than that of Q235 after Tafel fitting. The rust layer impedances of the designed steels are higher than that of Q235.


2012 ◽  
Vol 249-250 ◽  
pp. 914-917
Author(s):  
Yuan Bin Zhang ◽  
Kai Zhang

Several E4303 type welding electrodes with different coating compositions were designed and manufactured using TL-25 welding electrode extrusion press. Welding slags of these electrodes were collected after welding on the low carbon steel, then the microstructure and the phase constitutes of the slags were investigated by optical microscope,scan electron microscope (SEM), electron probe microanalyzer (EPMA), Transmission electron microscope (TEM) and X-ray diffraction (XRD). It was indicated that the slags were mainly composed of amorphous matrix and Fe2MnTi3O10 crystal phase. Fe, Mn and Ti were the main elements to form the crystal phase, while Si, Al and Ca were mostly distributed in the amorphous matrix. The formation of the crystal phase in the slag could be controlled by adjusting the amount and the proportion of Fe, Mn and Ti in the welding rod coating.


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