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.

Corrosion and Protection of Superalloys

2002 ◽  
pp. 287-322
Keyword(s):  
High Temperature ◽  
Hot Corrosion ◽  
Protective Coatings ◽  
High Temperature Corrosion ◽  
Oxide Growth ◽  
Mixed Gas ◽  
Gas Corrosion ◽  
Mixed Gases ◽  
Oxidation And Corrosion ◽  
Associated Data

Abstract Superalloys tend to operate in environments where they are subjected to high-temperature corrosion, oxidation, and the erosive effects of hot gases. This chapter discusses the nature of these attacks and the effectiveness of various protection methods. It describes the primary forms of oxidation, the development of protective oxides, and the conditions associated with mixed gas corrosion and hot corrosion attack. It discusses oxidation and corrosion testing, the equipment used, and various ways to present the associated data. It describes the effect of gaseous oxidation on different alloys, discusses the formation of oxide scale in the presence of mixed gases, and explains how alloy composition contributes to oxide growth. The chapter discusses the underlying chemistry of hot corrosion, how to identify its effects, and how it progresses under various conditions. It also discusses protective coatings, including aluminide diffusion, overlay, and thermal barrier types, and how they perform in different environments based on their ability to tolerate strain.

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.

Aluminide Protective Coatings Obtained by Slurry Method

2014 ◽  
Vol 782 ◽  
pp. 590-593 ◽  
Author(s):  
Agnieszka Kochmańska ◽  
Paweł Kochmański
Keyword(s):  
Titanium Alloy ◽  
Nickel Alloy ◽  
Protective Coatings ◽  
Cast Steel ◽  
Technological Parameters ◽  
Inorganic Binder ◽  
Air Atmosphere ◽  
Aluminide Coatings ◽  
Slurry Method

The slurry aluminide coatings are produced on the three kind of substrates: hightemperature creep resistant cast steel, titanium alloy and nickel alloy. The slurry as active mixture containing aluminium and silicon powders, an activator and an inorganic binder. The coating were obtained by annealed in air atmosphere. The structure of these coatings is two zonal and depend on the type of substrate and technological parameters of producing.

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.

INCONEL ALLOY 671

Alloy Digest ◽  
1972 ◽  
Vol 21 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Chromium Alloy ◽  
Inconel Alloy ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract INCONEL ALLOY 671 is a nickel-chromium alloy having excellent resistance to high-temperature corrosion. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-180. Producer or source: Huntington Alloy Products Division, An INCO Company.

ROLLED ALLOYS HR-120

Alloy Digest ◽  
2000 ◽  
Vol 49 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Thermal Processing ◽  
Hot Corrosion ◽  
Heat Treating ◽  
Temperature Performance

Abstract HR-120 alloy is an alloy designed for thermal processing. It possesses excellent strength, oxidizing hot corrosion resistance, good carburization resistance, and oxidation resistance through 1093 deg C (2000 deg F). This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-561. Producer or source: Rolled Alloys.

ACI TYPE HN

Alloy Digest ◽  
1982 ◽  
Vol 31 (6) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Steel Casting ◽  
Nickel Content ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Temperature Performance ◽  
Wide Range ◽  
Iron Chromium

Abstract Type HN is an iron-chromium-nickel alloy containing sufficient chromium for good high-temperature corrosion resistance and with nickel content in excess of the chromium. This alloy has properties somewhat similar to the more widely used ACI Type HT alloy but with better ductility. Type HN is used for highly stressed components in the 1800-2000 F temperature range. It is used in the aircraft, automotive, petroleum, petrochemical and power industries for a wide range of components and parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-410. Producer or source: Various stainless steel casting companies.

scholarly journals Exploring the Effect of Silicon on the High Temperature Corrosion of Lean FeCrAl Alloys in Humid Air

2021 ◽  
Author(s):  
T. Sand ◽  
A. Edgren ◽  
C. Geers ◽  
V. Asokan ◽  
J. Eklund ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Oxidation Behavior ◽  
High Temperature Corrosion ◽  
The Other ◽  
Oxide Scales ◽  
Protective Oxide ◽  
New Approach ◽  
Fecral Alloys ◽  
Cr Evaporation

AbstractA new approach to reduce the chromium and aluminium concentrations in FeCrAl alloys without significantly impairing corrosion resistance is to alloy with 1–2 wt.% silicon. This paper investigates the “silicon effect” on oxidation by comparing the oxidation behavior and scale microstructure of two FeCrAl alloys, one alloyed with silicon and the other not, in dry and wet air at 600 °C and 800 °C. Both alloys formed thin protective oxide scales and the Cr-evaporation rates were small. In wet air at 800 °C the Si-alloyed FeCrAl formed an oxide scale containing mullite and tridymite together with α- and γ-alumina. It is suggested that the reported improvement of the corrosion resistance of Al- and Cr-lean FeCrAl’s by silicon alloying is caused by the appearance of Si-rich phases in the scale.

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