Entity

Time filter

Source Type

Durgāpur, India

Ghosh D.,NDT and Metallurgy Group | Roy H.,NDT and Metallurgy Group | Mitra S.K.,National Institute of Technology Durgapur
Journal of Adhesion Science and Technology | Year: 2015

This paper investigates the effect of nano-size and micron-size Y2O3 powder-coated specimen on high-temperature oxidation resistance of low-alloy Cr-Mo steel (2.25 Cr-1 Mo steel). Both are powder coated by plasma spray coating method. The oxidation rate and reaction kinetics are studied and the post-corroded scales are characterized in Field Emission Scanning Electron Microscope and X-ray Diffraction. The results clearly indicate that nanosize Y2O3-coated (nanostructured) specimen improves the high-temperature oxidation resistance in comparison to the micron-size Y2O3-coated specimen. The detail mechanism of the oxidation of both the coated specimen is discussed in detail in this paper. © 2015 Taylor & Francis. Source


Ghosh D.,NDT and Metallurgy Group | Mukherjee S.,National Institute of Technology Durgapur | Das S.,NDT and Metallurgy Group
Protection of Metals and Physical Chemistry of Surfaces | Year: 2015

Ceria (CeO2) based high temperature coating was developed over 9Cr-1 Mo steel substrate. The coating is produced by plasma spray coating method by using robotic arm. Isothermal corrosion study of the CeO2 coated and uncoated specimen was conducted at 973 K for 8 h. The corrosion rate and reaction kinetics were studied and the post corroded scales were characterized in SEM, EDS and XRD. The results clearly indicate that ceria (CeO2) coated specimen improves the high temperature oxidation resistance than uncoated specimens. The kinetic behaviour of both coated and uncoated specimen follows approximate parabolic growth rate which further indicates that the corrosion is diffusion controlled growth. The post corroded scale of the coated specimen shows fine grained oxide scale with no scale cracking and detachment. The improvement of oxidation resistance in presence of CeO2 coating can be attributed to the formation of fine grained oxide on the scale, changed mechanism of scale growth from outer cation migration to inner anion migration and enhancement of scale adhesion with the substrate. The detail mechanism of the oxidation of CeO2 coated specimen and uncoated specimen is further discussed in this paper. © 2015, Pleiades Publishing, Ltd. Source


Ghosh D.,NDT and Metallurgy Group | Mukherjee S.,National Institute of Technology Durgapur | Das S.,NDT and Metallurgy Group
Surface Engineering | Year: 2014

This paper investigates the effect of yttria (Y2O3) coating on high temperature oxidation behaviour of low alloy 2.25Cr-1Mo steel. The superficial coating is Y2O3, which was prepared for experimental investigation. The isothermal corrosion study of uncoated and coated specimens was carried out in air oxidation environment at 973 K for 8 h. The corrosion rate and reaction kinetics were studied and the post-corroded scales were characterised by SEM, Energydispersive X-ray spectroscopy and X-ray diffraction. The results clearly indicate that Y2O3 coated specimen improves the high temperature oxidation resistance than uncoated specimen. The improvement of oxidation resistance in presence of Y 2O3 coating can be attributed to the modification of grain structure of the scale, changed mechanism of scale growth and enhancement of scale adhesion with the substrate. The detailed mechanism of the oxidation of Y2O3 coated and uncoated specimen is further discussed in this paper. © 2014 Institute of Materials, Minerals and Mining Published by Maney on behalf of the Institute. Source


Ghosh D.,NDT and Metallurgy Group | Mukherjee S.K.,National Institute of Technology Durgapur | Das S.,NDT and Metallurgy Group | Mitra S.K.,National Institute of Technology Durgapur
Surface Engineering | Year: 2015

This paper investigates the influence of ceria (CeO2) coating on high temperature oxidation behaviour of 2·25Cr-1Mo steel. The superficial coating of CeO2 powder was prepared for experimental investigation. The isothermal corrosion study of uncoated and coated specimens was carried out in air oxidation environment at 973 K for 8 h. The corrosion rate and reaction kinetics were studied and the post corroded scales were characterised in scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction. The results clearly indicate that CeO2 coated specimen improves the high temperature oxidation resistance than uncoated specimen. The improvement of oxidation resistance in presence of CeO2 coating can be attributed to the formation of fine grained oxide on the scale, changed mechanism of scale growth from outer cation migration to inner anion migration and enhancement of scale adhesion with the substrate. The detail mechanism of the oxidation of CeO2 coated and uncoated specimen was further discussed in this paper. © 2015 Institute of Materials, Minerals and Mining Published by Maney on behalf of the Institute. Source


Ghosh D.,NDT and Metallurgy Group | Ray S.,NDT and Metallurgy Group | Mandal A.,Central Research Facility CRF | Roy H.,NDT and Metallurgy Group
High Temperature Materials and Processes | Year: 2015

This paper highlights a case study of typical premature failure of a radiant platen superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement and chemical analysis, are conducted as part of the investigations. Apart from these, metallographic analysis and fractography are also conducted to ascertain the probable cause of failure. Finally it has been concluded that the premature failure of the super heater tube can be attributed to localized creep at high temperature. The corrective actions has also been suggested to avoid this type of failure in near future. © 2015 Walter De Gruyter. All rights reserved. Source

Discover hidden collaborations