scholarly journals High-Temperature Corrosion Behaviour of HVOF Sprayed Cr3C2- 25NiCr Coated on Alloy X22CrMoV12-1 at 600o C

2018 ◽  
Vol 1 (1) ◽  
pp. 7-12
Author(s):  
P. Akshay Prasanna ◽  
◽  
P. Subramani ◽  
V. Sreenivasulu ◽  
N. Arivazhagan ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Molten Salt ◽  
Hot Corrosion ◽  
Corrosion Behaviour ◽  
High Temperature Corrosion ◽  
Spinel Oxide ◽  
Good Resistance ◽  
Good Corrosion Resistance ◽  
Temperature Environment

The present study investigates the hot corrosion behaviour of high-velocity oxy-fuel sprayed alloy X22CrMoV12-1 with Cr3C2-25NiCr coating at 600oC. The study was carried out by air and molten salt environment for both coated and uncoated substrates for 50 cycles. Thermogravimetry analysis was carried out to evaluate the hot corrosion by calculating the mass changes in each cycle. The results show that coating provides the marginally good corrosion resistance than the uncoated alloy. The formation of Fe2O3 and MoO3 phases in the uncoated substrates in both air and molten salt environments reduces the corrosion resistance at the high-temperature environment. The formation of Ni2Oand spinel oxide NiCr2O4 provided good resistance to corrosion in the coated substrates in the air and molten salt environment.

Cyclic high temperature corrosion studies of carbon nanotubes-Cr2O3composite coatings on boiler steel at 900°C in molten salt environment

2018 ◽  
Vol 65 (6) ◽  
pp. 646-657 ◽  
Author(s):  
Khushdeep Goyal ◽  
Hazoor Singh ◽  
Rakesh Bhatia
Keyword(s):  
Carbon Nanotubes ◽  
Corrosion Resistance ◽  
Weight Gain ◽  
High Temperature ◽  
Hot Corrosion ◽  
Corrosion Behaviour ◽  
Composite Coatings ◽  
High Temperature Corrosion ◽  
Content Type ◽  
Coating Matrix

PurposeMolten 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 Cr2O3composite coatings on hot corrosion behaviour of ASTM-SA213-T22 steel in a corrosive environment of Na2SO4– 60%V2O5at 900°C for 50 cycles.Design/methodology/approachThe 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.FindingsDuring investigations, the carbon nanotubes (CNT) reinforced Cr2O3composite 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.Research limitations/implicationsThe 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.Originality/valueIt must be mentioned here that high temperature corrosion behaviour of thermally sprayed CNT-Cr2O3composite 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.

CRONIFER 2328

Alloy Digest ◽  
1982 ◽  
Vol 31 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Treating ◽  
Good Resistance ◽  
High Chromium ◽  
Good Corrosion Resistance ◽  
Temperature Performance ◽  
High Nickel

Abstract CRONIFER 2328 is a titanium-stabilized, high-chromium and high-nickel austenitic stainless steel with additions of molybdenum and copper. It exhibits good corrosion resistance against sulfuric and phosphoric acids. Also, it has good resistance against pitting and stress-corrosion cracking. Cronifer 2328 is used widely in the chemical industry for equipment and for the storage and transportation of various acids and solutions. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-411. Producer or source: Vereingte Deutsche Metallwerke AG.

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 Resistance Properties of Al-Si Coatings Obtained by Slurry Method

2012 ◽  
Vol 326-328 ◽  
pp. 273-278 ◽  
Author(s):  
Agnieszka Kochmańska
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Hot Corrosion ◽  
Protective Coatings ◽  
Cast Steel ◽  
High Temperature Corrosion ◽  
Air Atmosphere ◽  
Before And After ◽  
Slurry Method ◽  
Thermal Shocks

This paper presents the results of research on aluminide protective coatings manufactured on hightemperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, at carburizing and oxidizing potential atmosphere. Coatings were obtained on cast steel type GXNiCrSi 3018 by slurry cementation in air atmosphere. The tests of carburizing and oxidizing were carried out. The structure of the coatings before and after carburizing and oxidizing is described in the present paper. The chemical composition, thickness and microstructure of coatings were determined. These coatings could protect equipment against hot corrosion at carburizing and oxidizing atmosphere and have thermal shocks resistance.

Paper 9: Ceramic-Metal Composites: Nucerite

1965 ◽  
Vol 180 (4) ◽  
pp. 193-199
Author(s):  
W. Wood
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Abrasion Resistance ◽  
High Temperature Corrosion ◽  
Metal Composite ◽  
Base Metals ◽  
Metal Composites ◽  
Good Corrosion Resistance ◽  
Wide Range ◽  
New Material

This paper describes ‘Nucerite’, a new material of construction consisting of a ceramic-metal composite which has improved mechanical strength and abrasion resistance over glassed steel. A wide range of ceramics is available and these can be bonded to a range of base metals, thus giving a very wide choice of properties. An outline of the induced crystalline structure in the ceramic shows how Nucerite is suitable for high temperature use together with good corrosion resistance. The application of Nucerite in the chemical and related industries shows how its versatility can be used to solve high temperature, corrosion, and abrasion problems. Examples of items of equipment, together with the conditions under which they are being used, confirms that there is a big future for Nucerite as it is developed and its properties are improved even further.

Characterization and hot corrosion behavior of D-gun sprayed Cr2O3-75% Al2O3 coated ASTM-SA210-A1 boiler steel in molten salt environment

2017 ◽  
Vol 64 (5) ◽  
pp. 515-528 ◽  
Author(s):  
Amita Rani ◽  
Niraj Bala ◽  
C.M. Gupta
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Molten Salt ◽  
Corrosion Behavior ◽  
Hot Corrosion ◽  
Degradation Mechanism ◽  
Effective Diffusion ◽  
Boiler Steel ◽  
Content Type ◽  
Scanning Electron

Purpose Hot corrosion is the major degradation mechanism of failure of boiler and gas turbine components. The present work aims to investigate the hot corrosion resistance of detonation gun sprayed (D-gun) Cr2O3-75 per cent Al2O3 ceramic coating on ASTM-SA210-A1 boiler steel. Design/methodology/approach The coating exhibits nearly uniform, adherent and dense microstructure with porosity less than 0.8 per cent. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of bare and coated boiler steel in molten salt environment (Na2SO4-60 per cent V2O5) at high temperature 900°C for 50 cycles. The corrosion products are analyzed by using X-ray diffraction, scanning electron microscopy (SEM) and field emission scanning electron microscope/energy-dispersive analysis (EDAX) to reveal their microstructural and compositional features for elucidating the corrosion mechanisms. Findings During investigations, it was found that the Cr2O3-75 per cent Al2O3 coating on Grade A-1 boiler steel is found to be very effective in decreasing the corrosion rate in the molten salt environment at 900°C. The coating has shown lesser weight gains along with better adhesiveness of the oxide scales with the substrate till the end of the experiment. Thus, coatings serve as an effective diffusion barrier to preclude the diffusion of oxygen from the environment into the substrate boiler steel. Research limitations/implications Therefore, it is concluded that the better hot corrosion resistance of the coating is due to the formation of desirable microstructural features such as very low porosity, uniform fine grains and the flat splat structures in the coating; as compared to the bare substrate under cyclic conditions. Practical implications This research is useful for coal-fired boilers and other power plant boilers. Social implications This research is useful for power generation plants. Originality/value There is no reported literature on hot corrosion behavior of Cr2O3-75 per cent Al2O3 coating deposited on the selected substrates by D-gun spray technique. The present work has been focused to study the influence of the Cr2O3-75 per cent Al2O3 coating developed with D-gun spraying technique on high temperature corrosion behavior of ASTM-SA210-A-1 boiler steel in an aggressive environment of Na2SO4-60 per cent V2O5 molten salt at 900°C under cyclic conditions.

Corrosion Behaviour of Ti-48Al-2Nb-2Cr Alloys

2012 ◽  
Vol 323-325 ◽  
pp. 301-307
Author(s):  
B. Pelic ◽  
D. Rafaja ◽  
Patrick J. Masset ◽  
H.J. Seifert ◽  
L. Bortolotto ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Protective Coatings ◽  
Corrosion Behaviour ◽  
Base Material ◽  
High Temperature Corrosion ◽  
Al Alloy ◽  
Environmental Embrittlement ◽  
Structural Applications

γ-TiAl intermetallics are attractive materials for high-temperature structural applications in the aerospace and automobile industries. However, they show environmental embrittlement at elevated temperatures that is mainly related to their low high-temperature corrosion resistance. One way how to improve the high-temperature corrosion resistance is the deposition of protective coatings on the surface of the base material. In this study, samples of a Ti-Al alloy with the chemical composition Ti-48Al-2Cr-2Nb (at.%) were covered by physically vapour deposited (PVD), by metalorganic chemically vapour deposited (MOCVD) and by high-velocity oxy-fuel (HVOF) sprayed coatings. All coatings were based on the Ti-Al alloys and contained different amounts of alloying elements. The corrosion experiments were performed in molten salts containing 75 wt.% Na2SO4and 25 wt.% NaCl at 850°C up to 336 h. Both, PVD and CVD protected coatings reduced the changes in the mass of the samples over the corrosion time. Still, the formation of TiO2could not be avoided, as it was confirmed by glancing-angle X-ray diffraction experiments.

scholarly journals Comparison of High Temperature Corrosion Resistance in Gaseous Environment of Alloys based on Intermetallic Phase Matrix Fe40Al5CrZrb And Steel X12CrCoNi2120

2014 ◽  
Vol 59 (2) ◽  
pp. 447-450 ◽  
Author(s):  
J. Cebulski ◽  
A. Fornalczyk ◽  
D. Pasek
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
High Temperature ◽  
Intermetallic Phase ◽  
Steel Corrosion ◽  
High Temperature Corrosion ◽  
Steel Grade ◽  
Corrosion Resistant ◽  
Good Corrosion Resistance ◽  
Gaseous Environment

Abstract The paper presents results of the research which aim was to compare the corrosion resistance of alloys based on intermetallic phase after Fe40Al5CrTiB crystallization and after forming the steel corrosion resistant X12CrCoNi2120 species. The tests were performed for steel at temperature of 700°C Fe40Al5CrTiB and for alloy at 1100°C and 9% O2 0.2% HCl + SO2+ 0.08 N2 environment. In the research the changes of weight after corrosion tests, observations of the surface, specified chemical and phase composition of corrosion products were made. The obtained results of the study showed a very good corrosion resistance of Fe40Al5CrTiB alloys in high temperature and environments containing oxygen, sulfur and chlorine as compared to the corrosion resistance of the steel grade X12CrCoNi2120. Results of the research conducted in this scope are the basis for further research.

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