High Temperature Erosion-Corrosion in Gas Turbines

1982 ◽  
Author(s):  
J. Stringer
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
High Temperature Oxidation ◽  
Metal Loss ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
Oxidation Processes ◽  
Erosion Corrosion ◽  
Burning Coal ◽  
High Temperature Erosion

Under certain circumstances, hot gases containing particulates may be expanded through a turbine. The erosion damage due to the particulates interacts with the high temperature oxidation processes. The interaction may be positive: the oxide layer may be more erosion-resistant than the substrate. The interaction may be negative: the erosion can remove the protective oxide resulting in accelerated metal loss. If the gases contain corrosive materials such as alkali sulfates as well as the particulates, further interactions are possible. These processes are of importance in gas turbine expanders for pressurized fluidized bed combustors burning coal, and several research projects are in progress to study them.

scholarly journals The Impact of Surface Treatment on the Structure and Chemistry of Protective Oxide-Scale in High-Temperature Oxidation-Resistant Nickel Alloys

2020 ◽  
Vol 26 (S2) ◽  
pp. 280-282
Author(s):  
Stephen House ◽  
Henry Ayoola ◽  
John Lyons ◽  
Meng Li ◽  
Bingtao Li ◽  
...  
Keyword(s):  
High Temperature ◽  
Surface Treatment ◽  
Oxide Scale ◽  
Nickel Alloys ◽  
High Temperature Oxidation ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
Protective Oxide Scale ◽  
Oxidation Resistant ◽  
The Impact

The Effect of NaCl(g) in High Temperature Oxidation

1982 ◽  
Author(s):  
J. G. Smeggil ◽  
N. S. Bornstein
Keyword(s):  
High Temperature ◽  
Sodium Chloride ◽  
Gas Turbine ◽  
High Temperature Oxidation ◽  
Condensed State ◽  
Relative Importance ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
High Temperature Materials ◽  
Nacl Vapor

Sodium chloride can be present in gas turbine hot sections in the vapor as well as the condensed state. Particles containing sodium chloride may randomly break from compressor components, then impinge upon and stick to turbine components further down the gas path. However, NaCl vapor can deleteriously affect processes involving the formation and maintenance of protective oxide layers on turbine components. The relative importance of these two distinctly different mechanisms involving NaCl in corrosion processes is currently unknown. Numerous studies have dealt with the effect on corrosion behavior of Na2SO4-NaCl condensed mixtures with appreciable amounts of NaCl. However, the possibility that low NaCl vapor activities effect major changes in oxide scale formation and retention is equally as probable as that involving condensed NaCl. Therefore, the results presented here will deal with effects of low activities of NaCl vapor (0.1–100 ppm) upon scales formed by selected high temperature materials.

The Effect of Laser Glazing on High Temperature Oxidation Resistance of Thermal Barrier Coatings

2012 ◽  
Vol 433-440 ◽  
pp. 315-318
Author(s):  
Seyid Fehmi Diltemiz ◽  
Melih Cemal Kushan
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
High Temperature Oxidation ◽  
304 Stainless Steel ◽  
Thermal Barrier ◽  
Laser Glazing ◽  
Temperature Oxidation ◽  
Barrier Coatings

Thermal barrier coatings (TBCs) have been widely used by aero and land based gas turbines to protect hot section parts from oxidation and thermal loads. These coatings are generally consisting of multiple layers of coating (usually two) with each layer having a specific function. TBCs are generally deposited with air plasma spray (APS) or electron beam physical vapor deposition (EB-PVD) techniques. In this paper plasma sprayed TBCs were deposited on to 304 stainless steel substrates then ceramic surfaces were glazing with Nd-YAG laser. Metallographic examinations were applied to the samples to investigate microstructural changes in glazed ceramic layer. Both glazed and as-coated samples were subjected to oxidation tests to measure the high temperature oxidation resistance. The tests showed that, laser glazing is beneficial to oxidation resistance of TBCs. This improvement is attributed to sintering of zirconia layer which act as oxygen barrier and formed during glazing process.

scholarly journals Influence of Cooling Rate on the Failure Mechanisms of Protective Oxide Layers on Ni-Based Alloys After the High-Temperature Oxidation

2017 ◽  
Vol 10 (7) ◽  
pp. 952-960
Author(s):  
Nadezda V. Sukhodoeva ◽  
◽  
Vladimir V. Moskvichev ◽  
Elena N. Fedorova ◽  
◽  
...  
Keyword(s):  
High Temperature ◽  
Cooling Rate ◽  
High Temperature Oxidation ◽  
Failure Mechanisms ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
Oxide Layers

Effect of Phosphoric Acid Treatment on Isothermal High Temperature Oxidation Behaviour of AISI 304 Stainless Steel at 800°C

2012 ◽  
Vol 323-325 ◽  
pp. 359-364
Author(s):  
F. Riffard ◽  
Henri Buscail ◽  
F. Rabaste ◽  
Christophe Issartel ◽  
Sébastien Perrier
Keyword(s):  
High Temperature ◽  
Phosphoric Acid ◽  
Acid Treatment ◽  
High Temperature Oxidation ◽  
304 Stainless Steel ◽  
Protective Oxide ◽  
Temperature Oxidation ◽  
Aisi 304 ◽  
Oxidation Test ◽  
Aisi 304 Steel

Phosphoric acid treatment is used as a way to improve the high temperature oxidation resistance of a chromia-forming AISI 304 steel. Chromia-forming steels are excellent candidates to resist to high temperature oxidizing atmospheres because of the formation of protective oxide scales. The oxide scale growth mechanisms are studied by exposing phosphoric acid-treated and untreated 304 steel samples to high temperature conditions in air. The analyses were carried out by means of thermogravimetry, andin situX-ray diffraction (XRD). The experimental results show that the phosphoric acid treatment does not have a beneficial effect on cyclic high temperature oxidation (up to 70h of the oxidation test) of AISI 304 steel because of growth of a layer mainly formed by external cation diffusion which grows very quickly. The isothermal high temperature oxidation of this steel at 800°C in air shows a very fast initial iron oxidation towards the external interface, allowing to chromium element to be more available to the internal interface to form a continuous chromia layer, thus causing the establishment of a parabolic oxidation regime and leading to a beneficial reduction of the oxidation rate (after 70h of the oxidation test).

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