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This paper aims to investigate the hot corrosion behavior of Ni-Cr and Cr3C2-NiCr coatings, deposited on T11, P91 boiler steels by detonation gun spray coating (D-Gun) process to enhance high temperature corrosion resistance.

Hot corrosion studies were conducted in secondary super heater zone of boiler at 900 °C for 10 cycles on bare and D-Gun coated steel specimens. The microhardness and porosity values of as-sprayed coatings were measured before exposing the specimens in the boiler environment. Each cycle consisted 100 h of heating in the boiler environment followed by 20 min of cooling in air. The weight change measurements were performed after each cycle to establish the kinetics of corrosion using thermogravimetric technique. X-ray diffraction, SEM techniques were used to analyze the corroded specimens.

Uncoated boiler steel experienced higher weight loss. The Cr3C2-NiCr coating was found to be more protective than Ni-Cr coating. The phases revealed the formation of oxide scale on coated specimens, mainly consist of nickel and chromium, which are reported to be protective against the hot corrosion.

There is very limited reported literature on hot corrosion behavior of Ni-Cr and Cr3C2-NiCr coatings deposited on the T11 and P91 substrates by detonation gun (D-gun) spray technique. T11 and P91 alloy steels have been chosen for this study because these two alloys are used to manufacture boiler tubes used in Indian thermal power plants.

This paper aims to investigate hot corrosion behaviour of different Cr₃C₂–NiCr coatings on boiler tube steel.

High velocity oxy fuel technique has been used to deposit different coatings on commercially available ASTM-SA213-T22 boiler tube steel. The hot corrosion studies have been performed in molten salt environment at 900°C temperature in silicon tube furnace in laboratory.

The results showed that uncoated superalloy suffered intense spalling and the weight change was massive during each cycle on studies of hot corrosion 900°C. The 100 per cent NiCr and 10 per cent (Cr₃C₂) – 90 per cent (NiCr) coatings provided better protection to T22 steel against the hot corrosion because of the formation of Ni and Cr₃C₂ layers.

In this research a variety of coatings have been used. This research work has been aimed to investigate the hot corrosion behavior of Boiler Steel b with different Cr₃C₂–NiCr coatings, under molten salt environment in Silicon tube furnace at 900°C, under cyclic conditions.

This paper aims to use the high-velocity oxy fuel (HVOF) spraying process for depositing 93(WC–Cr₃C₂)–7Ni, 75Cr₃C₂–25NiCr, 83WC–17C_O and 86WC–10C_O–4Cr coatings on ASME SA213 T91 to study the corrosion resistance of these coatings in an actual boiler environment.

The HVOF spraying process was used for depositing 93(WC–Cr₃C₂)–7Ni, 75Cr₃C₂–25NiCr, 83WC–17C_O and 86WC–10C_O–4Cr coatings on ASME SA213 T91. All the coatings obtained are found to be uniform, dense and having thickness between 200 and 250 μm. All the coatings were exposed in an actual boiler environment at 900°C temperature for 10 cycles. Each cycle consisted of 100 h heating followed by 1 h cooling at ambient conditions. X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy techniques were used to analyse corrosion products.

All the coated samples were found to be having higher corrosion resistance than the uncoated samples. Among coated specimens, 93(WC–Cr₃C₂)–7Ni coating has shown maximum and 75Cr₃C₂–25NiCr coating has shown minimum resistance to corrosion.

This paper is original research.

This paper aims to discuss that a conventional Al₂O₃, 1.5 Wt.% carbon nanotubes (CNTs)-Al₂O₃, 2 Wt.% CNTs-Al₂O₃ and 4 Wt.% CNTs-Al₂O₃ composite coatings were deposited with the help of Plasma spray process.

To better understand the effect of CNT reinforcement on oxidation resistance, high-temperature oxidation behaviour of conventional Al₂O₃, 1.5 Wt.% CNTs-Al₂O₃, 2 Wt.% CNTs-Al₂O₃ and 4 Wt.% CNTs-Al₂O₃ composite coatings at 900°C was compared with the performance of the uncoated ASME-SA213-T11 boiler tube steel substrate.

The results showed that the CNT-reinforced alumina coatings exhibited better oxidation resistance and thermal stability than uncoated ASME-SA213-T11 boiler tube steel. The coated steel substrates had a lower mass gain rate than the substrate after different oxidation times.

Limited literature is available where the CNT have been reinforced into the composite alloy powders and has been thermally spray-deposited for various surface engineering applications. This research showed that with the increase in the percentage of CNTs into the alloy powder mixture, there is a significant reduction in weight gain and hence higher resistance to oxidation.

The purpose of this study was to fabricate carbon nanotubes (CNT)-reinforced chromium oxide coatings and investigate mechanical and microstructural properties of these newly developed coatings on the boiler tube steel.

1 and 4 Wt.% CNT-reinforced Cr₂O₃ composite coatings were prepared and successfully deposited on ASTM-SA213-T22 (T22) boiler tube steel substrates using high-velocity oxy fuel (HVOF) thermal spraying method. Microhardness, porosity, metallography, X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy, cross-sectional elemental analysis and X-ray mapping analysis have been used to examine the coated specimens.

The porosity of the CNT-Cr₂O₃ composite coatings was found to be decreasing with the increases in CNT content, and hardness has been found to be increasing with increase in percentage of CNT in the composite coatings. The CNT were able to increase hardness by approximately 17 per cent. It was found that the CNT were uniformly distributed throughout Cr₂O₃ matrix. The CNT were found to be chemically inert during the spraying process.

It must be mentioned here that studies related to fabrication of HVOF sprayed CNT reinforced Cr₂O₃ composite coatings on T22 boiler tube steel are not available in the literature. Hence, present investigation can provide valuable information related to fabrication and properties of CNT reinforced coatings on boiler steel.

Molten sulphate-vanadate induced hot corrosion is the main reason of failure of boiler tubes used at high temperatures in thermal power plants. The hot corrosion can be encountered by applying thermal spray coatings on the alloy steels. In this perspective, this paper aims to attempt to investigate the effect of carbon nanotubes reinforcement on Cr₂O₃ composite coatings on hot corrosion behaviour of ASTM-SA213-T22 steel in a corrosive environment of Na₂SO₄ – 60%V₂O₅ at 900^°C for 50 cycles.

The coatings have been deposited with high velocity oxy fuel process. The samples were exposed to hot corrosion in a Silicon tube furnace at 900^°C for 50 cycles. The kinetics of corrosion behaviour were analysed by the weight gain measurements after each cycle. Corrosion products were analysed with X-ray diffraction, scanning electron microscopy, energy dispersive and cross-sectional analysis techniques.

During investigations, the carbon nanotubes (CNT) reinforced Cr₂O₃ composite coatings on T22 steel were found to provide better corrosion resistance in the molten salt environment at 900^°C. The coatings showed lower weight gain along with formation of protective oxide scales during the experiment. Improvement in protection against hot corrosion was observed with increase in CNT content in the coating matrix.

The addition of CNT has resulted in reduction in porosity by filling the voids in chromium oxide coating, with interlocking of particle and has blocked the penetration of corroding species to enhance the corrosion resistance of the composite coatings. The corrosion rate was found to be decreasing with increase in CNT content in coating matrix.

It must be mentioned here that high temperature corrosion behaviour of thermally sprayed CNT-Cr₂O₃ composite coatings has never been studied, and it is not available in the literature. Hence, present investigation can provide valuable information for application of CNT-reinforced coatings in high temperature fuel combustion environments.

In Indian thermal power plants, the main cause of boiler tube failure is the presence of molten sulphates and vanadates, which deteriorate the tube material at high temperatures. To combat the hot corrosion failure of metals, thermal spray technology is adopted. This study aims to investigate and study the effect of hot corrosion behaviour of carbon nanotube (CNT)-reinforced ZrO₂-Y₂O₃ composite coatings on T-91 boiler tube steel in a molten salt environment at 900 °C for 50 cycles.

A plasma spray technique was used for development of the coatings. The samples were exposed to hot corrosion in a silicon tube furnace at 900 °C for 50 cycles. After testing, the test coupons were analysed by X-ray diffraction, scanning electron microscopy/energy dispersive spectroscopy and cross-sectional analysis techniques to aid understanding the kinetics of the corrosion reaction.

CNT-based reinforced coatings showed lower weight gain along with the formation of protective oxide scales during the experimentation. Improvement in protection against hot corrosion was observed with increase in CNT content in the coating matrix.

It is pertinent to mention here that the high temperature behaviour of CNT-reinforced ZrO₂-Y₂O₃ composite on T-91 steel at 900°C temperature in molten salt environment has never been studied. Thus, the present research was conducted to provide useful results for the application of CNT-reinforced composite coatings at elevated temperature.

The purpose of this paper is to present an organized review of existing research on reconfigurable manufacturing system (RMS). The paper considers majority of the prominent research articles in the domain of RMS published ever since RMS was envisaged in 1997.

The paper systematically reviews, classifies and analyses the published literature on postulations and design of RMSs. The general observations from the literature and research gaps recognized thereon are highlighted at the end of each section/sub-section.

The paper reveals important aspects related to RMS research since its inception. It also recognizes the areas of RMS research requiring more focus. The study also highlights open issues and future directions for further research.

The literature in the domain of RMS has so far been narrow. This paper reviews the prominent research in this field and presents an overview of its conceptual developments and various mathematical models for the RMS design and its optimization so far developed by the researchers. Further, manufacturing advancements and future directions have also been proposed for the efficient execution of RMS paradigm in manufacturing industries.

The paper provides an organized listing of published research work in the field of RMS. This work will provide an insight to the researchers, practitioners and others related directly or indirectly to this field to develop and understand better strategies for supervising and controlling the smooth implementation of RMS.

The real estate sector in India has assumed growing importance with the liberalisation of the economy. Developments in the real estate sector are being influenced by the developments in the retail, hospitality and entertainment (e.g. hotels, resorts and cinema theatres) segment, economic services (e.g. hospitals, schools) and information technology-enabled services (such as call centres), and vice versa. This paper aims to study the determinants of capital structure by taking into account 125 major Bombay Stock Exchange (BSE) listed real estate companies selected on the basis of their market capitalisation.

To discover what determines capital structure, nine firm level explanatory variables (profitability-EBIT margin, return on assets, earnings volatility, non-debt tax shield, tangibility, size, growth, age debt service ratio and tax shield) were selected and regressed against the appropriate capital structure measures, namely, total debt to total assets, long-term debts to total assets, short-term debts to total assets, total liabilities to total liabilities plus equity, total debt to capital used and total debt to total liabilities plus equity. A sample of 125 real estate companies was taken and secondary data were collected. Consequently, multivariate regression analysis was made based on financial statement data of the selected companies over the study period of 2009-2015.

The major findings of the study indicated that profitability, size, age, debt service capacity growth and tax shield variables are the significant firm-level determinants.

The present study is carried out by taking data of only 25 companies listed on the BSE and time period covered from 2009 from 2015. Time period and sample size may be limitations of the current study.

The present study is an empirical analysis of the determinants of leverage of real estate sector in India with most recent available data. Different regression equations have been formed to develop the models using firm-specific determinants and different measures of leverage or capital structure. Data were regressed using SPSS application software, and the resulting (or obtained) regression outputs are analysed. This study will help the Indian real estate companies to the know the impact of different variables while raising short-term and long-term loans.

The current study will benefit all stakeholders of society who are fascinated to be acquainted with the financing of real estate companies and the factors affecting long-term and short-term financing of this sector. Specifically, public engrossed in different modes of investment and financial institution will be the prime gainers.

The present study has been completed using authentic data from the annual reports and database. This study uses explanatory variables and different measures of leverage which were limited in use in previous studies. Moreover, this research is a comprehensive study that deals with developing different regression models by using diverse measures of leverage.