Performance investigation of high velocity flame sprayed multi-dimensional Ni-TiO2 and Ni-TiO2-Al2O3 coated hydro turbine steel under slurry erosion

Wear ◽  
2020 ◽  
Vol 462-463 ◽  
pp. 203498
Author(s):  
Vibhu Sharma ◽  
Manpreet Kaur ◽  
Sanjeev Bhandari
Keyword(s):  
High Velocity ◽  
Slurry Erosion ◽  
Hydro Turbine ◽  
Turbine Steel

Slurry Erosion of High Velocity Oxy-fuel Thermal Sprayed Coatings

1997 ◽  
Author(s):  
B. Arsenault ◽  
J.-G. Legoux ◽  
H. Hawthorne
Keyword(s):  
High Velocity ◽  
Surface Engineering ◽  
National Research Council ◽  
Volume Ratio ◽  
Jet Impingement ◽  
Slurry Erosion ◽  
Hvof Coatings ◽  
Carbide Coatings ◽  
Coating Microstructure ◽  
Technology Group

Abstract Improvement of the high velocity oxy-fuel deposition (HVOF) process in the last decade has enhanced the microstructure of coatings in order to better perform against wear and corrosion. Indeed cermet and metal HVOF coatings are reliable and have excellent performance under slurry erosion and provide therefore an alternative to the use of high-priced material. This paper presents the results of a study undertaken within the core research program of the National Research Council of Canada technology group in surface engineering, "SURFTEC", in which the performance of ten HVOF erosion-resistant coatings was evaluated. Ten different types of HVOF coatings were studied including: six grades of WC with either Co or a Ni based matrix, one grade of Cr3C2 in a Ni-Cr matrix, and three grade of metallic alloy: Ni alloy, Co alloy and a SS 316- L. The performance of coatings was evaluated with respect to: the volume ratio and composition of metallic binder in carbide coatings, type of carbide, coating microstructure, impinging angle and the size of the erodent particles. All coatings were produced using the HVOF JP-5000 system controlled by the Hawcs-ll controller. Slurry erosion tests were conducted with a jet impingement rig with a 10 %w/w alumina particle/water slurry. The volume loss of material under various slurry erosion conditions was related to the coating properties and microstructure. Results indicate that the behavior of HVOF sprayed materials is dependent on the erodent particle size, to the erosion impinging angle to some extent and to the corrosion resistance of the cermet matrix.

Mechanical properties and erosive behaviour of 10TiO2-Cr2O3 coated CA6NM turbine steel under accelerated conditions

2019 ◽  
Vol 16 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Khushdeep Goyal
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Average Particle Size ◽  
Average Particle ◽  
Slurry Erosion ◽  
Experimental Conditions ◽  
Content Type ◽  
Uncoated Steel ◽  
Erosion Test ◽  
Turbine Steel

Purpose This paper aims to evaluate the mechanical properties and slurry erosion behaviour of 10TiO2-Cr2O3 coated turbine steel. Design/methodology/approach Slurry erosion experiments were performed on the coated turbine steel specimens using slurry erosion test rig under accelerated conditions such as rotational speed, average particle size and slurry concentration. Surface roughness tester, Vickers microhardness tester and scanning electron microscope were used to analyse erosion mechanism. Findings Under all experimental conditions, 10TiO2-Cr2O3 coated steel showed better slurry erosion resistance in comparison with Al2O3 coated and uncoated steel specimens. Each experimental condition indicated a significant effect on the erosion rate of both coatings and uncoated steel. The surface analysis of uncoated eroded specimen revealed that plastic deformation, ploughing and deep craters formation were the reasons for mass loss, whereas microchipping, ploughing and microcutting were the reasons for mass loss of coated specimens. Originality/value The present investigation provides novel insight into the comparative slurry erosion performance of high velocity oxy fuel deposited 10TiO2-Cr2O3 and Cr2O3 coatings under various environmental conditions. To form modified powder, 10 Wt.% TiO2 was added to 90 Wt.% Cr2O3.

Effect of Impingement Angle on Erosion Resistance of HVOF Sprayed WC-10Co-4Cr Coating on CA6NM Steel

2017 ◽  
Vol 751 ◽  
pp. 79-83 ◽  
Author(s):  
Anurag Hamilton ◽  
Ashok Sharma ◽  
Upender Pandel
Keyword(s):  
Erosion Resistance ◽  
Solid Particle Erosion ◽  
Impingement Angle ◽  
X Ray ◽  
Hydro Turbine ◽  
Air Jet ◽  
Hvof Process ◽  
Coating Microstructure ◽  
Turbine Steel ◽  
Ca6nm Steel

In the present investigation, WC–10Co–4Cr coating was deposited by high velocity oxy-fuel (HVOF) process on CA6NM hydro turbine steel to improve its erosion resistance. The coating was characterized in term of crossectional microstructure, phase, microhardness and fracture toughness using a field emission scanning electron microscope (FESEM), X-ray diffractometer and microhardness tester respectively. Solid particle erosion resistance of the substrate and coating were evaluated by air jet erosion tester at two different impingement angles (30° and 90°). Coating microstructure has shown a homogeneous and well-bonded laminar morphology. The microhardness of the coating was observed more than three times higher than CA6NM substrate. This resulted in significant improvement in erosion resistance of coated CA6NM steel at both impingement angles.

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