Wear resistance of HVOF sprayed NiSiCrFeB, WC-Co/NiSiCrFeB, WC-Co, and WC-Cr3C2-Ni rice harvesting blades

2021 ◽  
Vol 63 (1) ◽  
pp. 62-72
Author(s):  
Ronnarit Khuengpukheiw ◽  
Charnnarong Saikaew ◽  
Anurat Wisitsoraat

Abstract In this work, NiSiCrFeB, WC-Co/NiSiCrFeB, WC-Co, and WC-Cr3C2-Ni coatings were sprayed on rice harvesting blade surfaces using a high velocity oxygen fuel (HVOF) process. Each of the rice harvesting blades was sprayed with one of four coating materials using different spraying durations. The effects of coating materials and spraying durations on the average values of coated blade volume loss, hardness and surface roughness (Ra) were studied through real rice-harvesting field tests. Analysis of variance (ANOVA) and a multiple comparison approach with Tukey’s test were used in order to conduct a comparative performance analysis of the coating materials of rice harvesting blades. The experimental results indicated that the NiSiCrFeB coating exhibited the highest volume loss compared with all others. In addition, the WC-Co-coated blade had significantly greater hardness than those coated with NiSiCrFeB, WC-Co/NiSiCrFeB, or WC-Cr3C2-Ni. The rice harvesting blade coated with either WC-Co/NiSiCrFeB, WC-Co, or WC-Cr3C2-Ni using the shortest spraying duration was recommended for installation in rice harvesting machines.

Author(s):  
S.Y. Hwang ◽  
B.G. Seong ◽  
M.C. Kim

Abstract To maintain surface roughness of process rolls in cold rolling steel plants, WC-Co coatings have been known to be effective ones. In this study, a high pressure/high velocity oxygen fuel (HP/HVOF) process was used to obtain WC-Co coatings. To get the best quality of coatings, WC-Co coatings are sprayed with numerous powders made by various processes. These powders include agglomerated sintered powders, fused-crushed powders, extra high carbon WC-Co powders and (W2C, WC)-Co powders. After spraying, properties of coatings such as hardness, wear resistance. X-ray diffraction, and microstructures were analyzed. For coatings produced by agglomerated-sintered powders, hardness of the coating increased as power levels and the number of passes were increased. In case of the coatings produced by fused-crushed powders, a very low deposition rate was obtained due to a low flowablity of the powders. In addition, the WC-Co coatings sprayed with extra carbon content of WC-Co did not show improved hardness and wear resistance. Also, some decomposition of WC was observed in the coating. Finally, the coatings produced by (W2C, WC)-Co powders produced higher hardness and lower wear resistance coating.


Author(s):  
Zhetcho Doinov Kalitchin ◽  
Mara Krumova Kandeva ◽  
Yana Petrova Stoyanova

This research work studies the characteristics of wear and wear resistance of composite powder coatings, deposited by high-velocity oxygen fuel, which contain composite mixtures Ni-Cr-B-Si having different chromium concentrations – 9.9%; 13.2%; 14%; 16% and 20% , at one and the same size of the particles and the same content of the remaining elements. The coating of 20% Cr does not contain B and Si. Out of each powder, composite coatings have been prepared without any preliminary thermal treatment of the substrate and with preliminary thermal treatment of the substrate up to 650оС. The coatings have been tested under identical conditions of dry friction over a surface of solid firmly attached abrasive particles using the tribological testing device „Pin-on-disk“. Results have been obtained and the dependences of the hardness, mass wear, intensity of the wearing process, absolute and relative wear resistance on the Cr concentration under identical conditions of friction. It has been found out that for all the coatings the preliminary thermal treatment of the substrate leads to a decrease in the wear intensity. Upon increasing Cr concentration the wear intensity diminishes and it reaches minimal values at 16% Cr. In the case of coatings having 20% Cr concentration, the wear intensity is increased, which is due to the absence of the components B and Si in the composite mixture, whereupon no inter-metallic structures are formed having high hardness and wear resistance. The obtained results have no analogues in the current literature and they have not been published by the authors.


2018 ◽  
Vol 929 ◽  
pp. 142-149 ◽  
Author(s):  
Myrna Ariati Mochtar ◽  
Wahyuaji Narottama Putra ◽  
Raditya Perdana Rachmansyah

Tube boiler operating condition initiates common problems that can occur as a problem in the wear resistance material. It leads to a decreased function of the material so that it is necessary to repair or replacement. High Velocity Oxygen Fuel (HVOF) is regarded as one of the effective methods to increase the wear resistance of the material. In this study, the materials were ASTM SA213-T91 as a material commonly used for boiler tube and JIS G 3132 SPHT-2 as an alternative material. In the early stages, both of specimens were given initial surface heating with temperature variations 0, 50, 100 and 150oC. The materials were then coated with Stellite-1 using HVOF method. The material were then characterized for the microstructure, porosity, hardness distribution, and wear resistant. The results showed that the coating Stellite-1 as a top coat with HVOF method can improve the performance of the material. Microhardness increases from 220 HV to 770 HV on ASTM SA213-T91, while on the substrate JIS G 3132 SPHT-2 the microhardness increased from 120 HV to 750 HV. Better wear resistance was achieved with increasing preheating [1]. Wear resistance of the materials increased from the range 3.69x10-7at 0°C preheating up to 0.89x10-7on a specimen with initial surface heating 150oC. Porosity also decreases with the increasing preheating temperature.


2012 ◽  
Vol 518-523 ◽  
pp. 3984-3988
Author(s):  
Bai Lin Zha ◽  
Xiao Jing Yuan ◽  
De Wen Wang

Environmental protection and worker safety measures against the extensively used hard chrome plating (EHC) is becoming more stringent, which leads to the development and application of alternative technology. As one of the most promising replacement technology of EHC, WC/Co coatings deposited by High Velocity Oxygen Fuel (HVOF) have well performances in corrosion and wear resistance. The paper analyzed technical characteristics, property and cost of EHC and HVOF deposited WC-Co coatings, while results show that performance of HVOF sprayed WC-Co coatings is superior or equal to EHC with much higher expense, so current replacement of EHC by HVOF centers airplane and military arm field which have relatively higher profit.


2019 ◽  
Vol 11 (5) ◽  
pp. 685-693 ◽  
Author(s):  
Zhidan Zhou ◽  
Xiubing Liang ◽  
Yongxiong Chen ◽  
Baolong Shen ◽  
Junchao Shang ◽  
...  

2015 ◽  
Vol 818 ◽  
pp. 32-36 ◽  
Author(s):  
Anna Guzanová ◽  
Janette Brezinová ◽  
Jozef Bronček ◽  
Pavlo Maruschak ◽  
Mariana Landová

The paper deals with the evaluation of coatings CoMoCrSi and WC-NiMoCrFeCo applied by High Velocity Oxygen Fuel technology from point of view of their suitability for renovation of sink roll in hot dip galvanizing line. The structure of the coatings was evaluated by metallographic analysis. The adhesion of the coatings as-sprayed and after thermal cyclic loading was determined by pull-off test. Wear resistance of the coatings was evaluated by pin-on-disc test in the corrosive environment of 1M aqueous solution of NaCl.


2018 ◽  
Vol 100 (1-4) ◽  
pp. 3-11 ◽  
Author(s):  
Angela Selau Marques ◽  
Luana De Lucca de Costa ◽  
Giovanni Rocha dos Santos ◽  
Alexandre da Silva Rocha

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