scholarly journals Residual Stress Characteristics of High Velocity Oxygen-Fuel MCrAlY Coatings.

1997 ◽  
Vol 46 (9) ◽  
pp. 1057-1063 ◽  
Author(s):  
Yoshiyasu ITOH ◽  
Masahiro SAITOH ◽  
Masashi TAKAHASHI
Keyword(s):  
Residual Stress ◽  
High Velocity ◽  
High Velocity Oxygen Fuel ◽  
Mcraly Coatings ◽  
Oxygen Fuel

Characteristics of MCrAlY Coatings Sprayed by High Velocity Oxygen-Fuel Spraying System

1999 ◽  
Vol 122 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Y. Itoh ◽  
M. Saitoh ◽  
M. Tamura
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
High Velocity ◽  
Gas Turbines ◽  
High Velocity Oxygen Fuel ◽  
Hvof Spraying ◽  
Vacuum Plasma ◽  
Mcraly Coatings ◽  
Plasma Sprayed ◽  
Oxygen Fuel

High velocity oxygen-fuel (HVOF) spraying system in open air has been established for producing the coatings that are extremely clean and dense. It is thought that the HVOF sprayed MCrAlY (M is Fe, Ni and/or Co) coatings can be applied to provide resistance against oxidation and corrosion to the hot parts of gas turbines. Also, it is well known that the thicker coatings can be sprayed in comparison with any other thermal spraying systems due to improved residual stresses. However, thermal and mechanical properties of HVOF coatings have not been clarified. Especially, the characteristics of residual stress, that are the most important property from the view point of production technique, have not been made clear. In this paper, the mechanical properties of HVOF sprayed MCrAlY coatings were measured in both the case of as-sprayed and heat-treated coatings in comparison with a vacuum plasma sprayed MCrAlY coatings. It was confirmed that the mechanical properties of HVOF sprayed MCrAlY coatings could be improved by a diffusion heat treatment to equate the vacuum plasma sprayed MCrAlY coatings. Also, the residual stress characteristics were analyzed using a deflection measurement technique and a X-ray technique. The residual stress of HVOF coating was reduced by the shot-peening effect comparable to that of a plasma spray system in open air. This phenomena could be explained by the reason that the HVOF sprayed MCrAlY coating was built up by poorly melted particles. [S0742-4795(00)00701-8]

COLMONOY NO. 43HV

Alloy Digest ◽  
2008 ◽  
Vol 57 (7) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
High Velocity ◽  
Base Alloy ◽  
Heat Treating ◽  
High Velocity Oxygen Fuel ◽  
Nickel Base Alloy ◽  
Nickel Base ◽  
Oxygen Fuel

Abstract Colmonoy No. 43HV comprises a nickel-base alloy recommended for hard surfacing parts to resist wear, corrosion, heat, and galling. Deposits that have moderate hardness have increased ductility and slightly less resistance to abrasion than Colmonoy 53HV. Deposits can be finished by grinding or machined with carbide tooling. Colmonoy No. 43HV is supplied as an atomized powder specially sized for application with high-velocity oxygen fuel (HVOF) systems. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance and surface qualities as well as heat treating and surface treatment. Filing Code: Ni-664. Producer or source: Wall Colmonoy Corporation.

Difference oxidation behaviors of Ni8Al and Ni25Cr coatings in air with water vapor at 650∘

2021 ◽  
pp. 2150274
Author(s):  
Dingjun Li ◽  
Wenlang Huang ◽  
Xiaohu Yuan ◽  
Taihong Huang ◽  
Chao Li ◽  
...  
Keyword(s):  
Water Vapor ◽  
High Velocity ◽  
Cyclic Oxidation ◽  
Oxidation Behaviour ◽  
Fuel Spray ◽  
High Velocity Oxygen Fuel ◽  
Service Environment ◽  
Generator Unit ◽  
Oxygen Fuel ◽  
Oxidation Behaviors

The oxidation behaviour of Ni8Al and Ni25Cr coatings produced by high velocity oxygen fuel spray (HVOF) which were deposited on Fe-based alloys (CB2) was investigated. We simulated the service environment of the steam generator unit, and put the samples in a thermostatic tube furnace at 650[Formula: see text] in air with 20 wt.% water vapor for 1000 hours of cyclic oxidation. The formation mechanism are explained using SEM, XRD, and EDX. There were no spallations and obvious cracks in both coatings. Ni25Cr coating generated a better protection oxides scale than that scale on Ni8Al. The behavior and mechanism of the oxide scale formation had an important influence in coatings and we have discussed these phenomenons in the study.

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