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| Abstract No.: |
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Scheduled at:
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Wednesday, May 05, 2010, Hullet Room 12:20 PM
Corrosion Protection
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| Title: |
Cyclic oxidation behavior of HVOF sprayed Ni-20Cr coating on ASTM-SA213-T 22 boiler steel at 900°C
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| Authors: |
Gagandeep Kaushal* / Punjab Technical University, India
Harpreet Singh Saheet / Indian Institute of Technology Ropar, INDIA
Satya Prakash/ Indian Institute of Technology, Roorkee, , INDIA
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| Abstract: |
In this study, HVOF thermal spray technique was used to deposit Ni-20Cr coating on a commonly used boiler steel ASTM-SA213-T-22.The specimens with and without coatings were subjected to cyclic oxidation testing at an elevated temperature of 900°C to ascertain usefulness of the coating. Weight change data was evaluated to approximate the kinetics of the oxidation. Each cycle consisted of 1 hour heating in a silicon carbide tube furnace followed by 20 min cooling in air. Thermogravimetric technique was used to approximate the kinetics of corrosion. The uncoated sample suffered intensive spallation along with a significant overall weight gain. The oxidation rate was found to reduce appreciably after the deposition of the coating by 87%. The exposed specimens were characterized by X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and electron probe microanalysis (EPMA). It was observed that HVOF sprayed Ni-20 Cr coating was suitable to provide oxidation resistance to the given steel in the air environment.
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