Hot Corrosion Studies of HVOF-Sprayed Cr3C2-NiCr Coating on 310S Stainless Steel in an Actual Environment of a Coal Fired Boiler

2012 ◽  
Vol 585 ◽  
pp. 483-487 ◽  
Author(s):  
V.N. Shukla ◽  
R. Jayaganthan ◽  
V.K. Tewari
Keyword(s):  
Stainless Steel ◽  
Hot Corrosion ◽  
Corrosion Behaviour ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Corrosion Studies ◽  
Super Heater ◽  
Actual Environment ◽  
Cyclic Studies ◽  
The Given

The present investigation is an attempt to evaluate the hot corrosion behaviour of high velocity-oxy fuel (HVOF) sprayed Cr3C2-25 % NiCr coating on 310S stainless steel in an actual industrial environment of a coal fired boiler. The cyclic studies were performed in the super heater zone of a coal-fired boiler where the temperature was around 700±100C. Experiments were carried out for 3 cycles each of 500 hours duration followed by 1 hour cooling in air till room temperature. X-ray diffraction (XRD) analysis and field emission scanning electron microscope (FESEM, FEI, Quanta 200F Company) with EDAX Genesis software attachment were used to analyse the oxidation-erosion products. The Cr3C2-25wt% NiCr coated specimen showed good adherence to the 310S SS substrate with negligible microspalling of the scales. The Cr3C2-25wt % NiCr coating deposited on 310S stainless steel imparted better hot corrosion resistance than the uncoated one in the given environment.

scholarly journals Study of Molten Salt Corrosion of Superni-75 using Termogravimetric Technique

1970 ◽  
Vol 3 (2) ◽  
pp. 77-82 ◽  
Author(s):  
TS Sidhu ◽  
S Prakash ◽  
RD Agrawal
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Hot Corrosion ◽  
Corrosion Behaviour ◽  
Thick Layer ◽  
X Ray Diffraction ◽  
Salt Corrosion ◽  
Marine Engineering ◽  
The Given ◽  
Kinetics Of

The present study aims to evaluate the hot corrosion behaviour of the Ni-based alloy Superni- 75 in the molten salt environment of Na2SO-60%V2O5 at 900°C under cyclic conditions. The thermogravimetric technique was used to establish the kinetics of corrosion. X-ray diffraction, scanning electron microscopy/energy-dispersive analysis and electron probe microanalysis techniques were used to analyse the corrosion products. Superni-75 has successfully provided the hot corrosion resistance to the given molten salt environment. The hot corrosion resistance of the Superni-75 has been attributed to the formation of uniform, homogeneous and adherent thick layer of the scale consisting mainly of oxides of nickel and chromium, and refractory Ni(VO3)2. These oxides and refractory nickel vanadates have blocked the penetration of oxygen and other corrosive species to the substrate. Keywords: Hot corrosion, nickel-based alloy, superalloy, molten salt environment   DOI: 10.3329/jname.v3i2.922 Journal of Naval Architecture and Marine Engineering 3(2006) 77-82

Hot corrosion behaviour of Super 304H for marine applications at elevated temperatures

2017 ◽  
Vol 64 (5) ◽  
pp. 508-514 ◽  
Author(s):  
M. Adam Khan ◽  
S. Sundarrajan ◽  
S. Natarajan
Keyword(s):  
Hot Corrosion ◽  
Elevated Temperatures ◽  
Corrosion Behaviour ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Salt Mixture ◽  
Content Type ◽  
X Ray ◽  
Different Temperatures ◽  
Marine Applications

Purpose The aim of this paper is to study the hot corrosion behaviour of super 304H stainless steel for marine applications. Design/methodology/approach The investigation was carried out with three different combinations of salt mixture (Na2SO4, NaCl and V2O5) at two different temperatures (800 and 900°C). Findings The spalling and growth of oxide layer was observed more with the presence of V2O5 in the salt mixture at 900°C during experimentation than what was observed in 800°C. The mass change per unit area is calculated to study the corrosion kinetics and also the influence of salt mixture. Further, the samples are analysed through materials characterisation techniques using optical image, scanning electron microscope (SEM), energy dispersive X-ray (EDAX) and X-ray diffraction (XRD) analysis. The presence of V2O5 in the salt mixture was the most important influencing species for accelerating hot corrosion. Originality/value SEM, EDAX and XRD analysis confirmed the formation of Fe2O3 and Cr2O3 at 900°C showing contribution in corrosion protection.

Microstructural and Corrosion Studies by Immersion in 3.5% NaCl Solution on Aged Mg-9Al-1Zn-XCa Alloy

2019 ◽  
Vol 969 ◽  
pp. 93-97
Author(s):  
S. Manivannan ◽  
B. Narenthiran ◽  
A. Sivanantham ◽  
S.P. Kumaresh Babu
Keyword(s):  
Corrosion Behaviour ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Corrosion Attack ◽  
X Ray ◽  
Α Phase ◽  
Corrosion Studies ◽  
Different Temperatures ◽  
Xrd Techniques ◽  
Scanning Electron

The experimatal alloys were aged at different temperatures of 180°C, 200°C, 220°C, and 240º C with calcium addition levels of (X=0.5, 1, 1.5, 2%) on Mg-6Al-1Zn-XCa alloy were investigated in 3.5% NaCl solution. All the experimatal alloys were immersed in 3.5% NaCl solutions and the resulted surface were analyzed to study the corrosion behaviour and its surface topography by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersed spectroscopy (EDS) and X-ray diffraction (XRD) techniques. The result shows that corrosion attack occurred predominantly on ß phase and α phase exhibit relatively minor corrosion. In addition to that the increased aging temperature coarsens the intermetallic as well as α- Mg grains, which shows adverse effect to corrosion resistances and the best result were obtained at composition of 0.5wt.% Ca aged at 200°C.

Experimental Analysis of Hot Corrosion Behaviour of some Composite Coatings on Boiler Steel at Elevated Temperature

2021 ◽  
Vol 41 ◽  
pp. 43-54
Author(s):  
Prince Puri ◽  
Khushdeep Goyal ◽  
Rakesh Goyal ◽  
Bal Krishan
Keyword(s):  
Hot Corrosion ◽  
Power Plants ◽  
Corrosion Behaviour ◽  
Composite Coatings ◽  
Thermal Power ◽  
Tube Steel ◽  
X Ray Diffraction ◽  
Boiler Steel ◽  
Boiler Tube Steel ◽  
Silicon Tube

Hot corrosion is the main reason of failure of boiler tubes used at high temperature in thermal power plants. This paper is an attempt to investigate the effect of different composite coatings on boiler tube steel in 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 weight change statistics, X-ray diffraction, and scanning electron microscopy. It is found that 100Cr3C2 composite coatings provided the higher resistance to corrosion as compared to other types of coatings. Cr carbide layer was formed on the surface and these layers provided the protection from hot corrosion.

A Comparative Study of Corrosion Behaviour of Amorphous and Nanocrystalline Ti60Ni40 in 0.5 M H2SO4 and 0.5 M HNO3 Aqueous Media

2009 ◽  
Vol 67 ◽  
pp. 179-184 ◽  
Author(s):  
Shubhra Mathur ◽  
Rishi Vyas ◽  
S.N. Dolia ◽  
Kanu Sachdev ◽  
S.K. Sharma
Keyword(s):  
Corrosion Behaviour ◽  
Aqueous Media ◽  
Amorphous State ◽  
Side Surface ◽  
Corrosion Current ◽  
Nanocrystalline Phase ◽  
X Ray Diffraction ◽  
Nanocrystalline State ◽  
X Ray ◽  
Corrosion Studies

Corrosion studies were carried out using potentiodynamic polarization method on amorphous, nanocrystalline and crystalline states of the alloy Ti60Ni40 in 0.5 M H2SO4 and 0.5 M HNO3 aqueous media at room temperature. The nanocrystalline state of Ti60Ni40 was obtained by removing about 10 μm from the air side surface (crystalline state) by polishing. The presence of nanocrystalline phase was confirmed by X-ray diffraction (XRD). It was found from polarization results that the corrosion current density was higher in the amorphous state than in the nanocrystalline state in both 0.5 M H2SO4 and 0.5 M HNO3 aqueous media. These results are corroborated by the weight loss studies which were carried out in both of these media. Results are discussed in the paper in the light of data reported in the literature on similar type of alloys.

Corrosion Behaviour of Nitronic Steel in Acidic Environment

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Himanshu Sharma ◽  
Anurag Bhardwaj ◽  
Daljeet Singh ◽  
Divyansh Mittal ◽  
Rajiv Kumar ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Corrosion Behaviour ◽  
Steel Corrosion ◽  
Optical Microscope ◽  
Acidic Environment ◽  
Acidic Solutions ◽  
Corrosion Studies ◽  
Structural Applications ◽  
Lower Corrosion Rate

Nitronic steel exhibits an austenitic matrix with carbide precipitates along the grain boundaries. The nitronic steel also shows excellent ductility (nearly 2 times of the other stainless steel) which enhances their structural applications. In the view of the performance of nitrogen alloyed steel, the corrosion behaviour of the as-received nitronic steels wasstudied and compared its corrosion behaviour with the conventional stainless steels being used in chemical and hydropower industries. The corrosion study of the nitronic steel and conventional stainless steels was performed in different aqueous solutions (H2SO4 and NaCl). The results obtained from corrosion studies suggest the lower corrosion rate of nitronic steel as compared to the conventional stainless steels. The corroded surfaces were analyzed using an optical microscope and scanning electron microscope for the elemental analysis of corrosion products. Keywords: Nitronic steel; Corrosion; Stainless steel; Acidic solutions

The Characteristic of Surface Layers on Austenitic Stainless Steel after Glow-Discharge Nitriding Process

2010 ◽  
Vol 165 ◽  
pp. 165-168 ◽  
Author(s):  
Artur Sitko ◽  
Marek Szkodo ◽  
Maria Gazda
Keyword(s):  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Diffusion Layers ◽  
Chemical Constitution ◽  
Scanning Electron

This paper presents investigation of surface layers. The diffusion layers were produced by using different parameters of reactive atmosphere (N2:H2). The research of the surface layers was performed using scanning electron microscope (SEM). The results of energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) analysis are presented. Research reveals the influence of chemical constitution of reactive atmosphere on the change of properties of nitrided layers.

Microstructure and mechanical properties of low temperature carburizing layer on AISI 440C martensitic stainless steel

2020 ◽  
Vol 10 (6) ◽  
pp. 841-847
Author(s):  
Fei Gao ◽  
Xiaoming Zong ◽  
Ling Tian ◽  
Sijia Quan
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Low Temperature ◽  
Processing Time ◽  
Martensitic Stainless Steel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Test Device ◽  
Microstructure And Mechanical Properties ◽  
Pin On Disc

In this study, the microstructure and mechanical properties of AISI 440C martensitic stainless steel with low temperature carburizing (LTC) layers were investigated by microscopes, X-ray diffraction (XRD), Vickers indenter and pin-on-disc test device, etc. LTC treatment was conducted at 420 °C for 10–40 h on the quenched-tempered steel samples by pack method. Results indicated that the LTC layers formed on base metal exhibited compact and regular morphology, and carbon-expanded martensite (α′c), Fe3C and Cr23C6 compounds were examined in the LTC layers by XRD analysis. Besides, the layer hardness from 1430 to 1720 HV0.025 with processing time increased, which was approximately three times higher than that of the specimen without LTC treatment. However, as the processing time increased, the adhesion strength of LTC layers deteriorated and the indentation grade decreased from HF1 to HF3. In addition, the wear resistance was significantly improved after the LTC treatment, and the wear rate of the LTC layer decreased by 93.7% in comparison with the untreated condition.

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