تاثیر پوشش های محافظ بر خواص مکانیکی سوپر آلیاژها Superalloys

The Effect of Protective Coatings on

the Mechanical Properties of Superalloys

تاثیر پوشش های محافظ بر خواص مکانیکی سوپر آلیاژها

ABSTRACT

COATINGS PROTECT the surface of tur- bine blades from damage caused by high-tem- perature corrosion and thus preserve the struc- tural shape of blades and their mechanical properties for the required time. There are many papers in the technical liter- ature that deal with experimental studies of heat resistance, fatigue strength, and thermal fatigue of coated superalloys. However, the connection between the physical and mechanical properties of protective coatings and their effect on the me- chanical properties of turbine-blade superalloys has not been studied sufficiently well. For thin diffusion coatings, this can be explained by the complexity of the task, both in reproducing the correct composition and in testing the coatings separately from the alloy. However, for these coatings, information on their physical and me- chanical properties is necessary for their proper application and for accurate calculations of coated-blades service lives.

 

فولادهای زنگ نزن آستنیتی نیکل پایین Low Nickel Austenitic Stainless Steels

Low Nickel Austenitic Stainless Steels 

فولادهای  زنگ نزن آستنیتی نیکل پایین

ABSTRACT

The most common grades of stainless steel are 304 and 316, which are particularly popular because  their austenitic microstructure results in an excellent combination of corrosion resistance, mechanical  and physical properties and ease of fabrication.  The austenitic structure is the result of the addition of approximately 8-10% nickel. Nickel is not alone  in being an austenite former; other elements that are used in this way are manganese, nitrogen,  carbon and copper. 

 

مواد دما بالا برای توربین ها گازی

: High Temperature Materials for Gas Turbines
The Present and Future

مواد دما بالا برای توربین ها گازی:

حال و آینده

ABSTRACT

Increased operating temperatures and higher efficiency in gas turbines and jet engines can reduce CO2 emission, thus contributing to the prevention of global warming. To achieve this goal, it is essential to improve the properties of high temperature materials. Various Ni-base superalloys are used for high-temperature components, e.g., combustors and high-pressure turbine blades and vanes, that determine the power and efficiency of jet engines and industrial gas turbines. Among them, single crystal (SC) superalloys have the highest temperature capabilities. A third-generation SC alloy has been used practically in Jet engines and fourth-generation SC alloys with platinum group metals additions are being developed for the next generation Jet engines. In land-based gas turbines also SC superalloys have been introduced to increase their inlet gas temperatures, and thus thermal efficiencies. As for new materials, intermetallic alloys, refractory alloys, ceramics, etc., are also being developed as possible alternative materials. Some unique materials have recently been proposed in Japan and being evaluated.