Applications of Superalloys
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Transcript of Applications of Superalloys
Applications of Superalloys
Alireza S. AkbariInstitut für Metallkunde und Metallphysik
RWTH Aachen
Seminar II – SS 07
Contents
General background on development of superalloys
Iron base superalloys (characteristics – applications)
Cobalt base superalloys (characteristics – applications)
Stellites (applications)
Nickel base superalloys (general classification –
characteristics)
Introduction to selected Ni-base superalloys (Inconel –
Hastelloy – Monel)
Some notes on superalloys
Development of superalloys since 1940 working temperature: 600°C –
1150°C resistance against high mechanical loads high oxidation and corrosion resistance
increase of high-temperature applicability
Forging
Investment Casting Directional
Solidification
Single Crystal Solidification
Application based on matrix material
FeOxidation resistance by Cr addition
High and room temp. strength
Creep, oxidation, corrosion and wear resistance
Application in turbine discs
e.g. Incoloy
Application based on matrix material
Co Ni, Cr and W as further alloying elements
Haynes 167
Combustion chambers
Nuclear reactors
Wear resistant materials
Application based on matrix material
Co Ni, Cr and W as further alloying elements
Haynes 167
Stellite 6B
Stellite 6B
handling extreme conditions of wear, abrasion, and heat
high hardness at high temps.
recovers full hardness after exposure to temps. up to 1100°C
excellent resistance to oxidation, corrosion and thermal shock
Applications
erosion shielding in steam turbines resistant top coats in gas turbines pipe elbow guiding in hot particles
at high temps.
Application based on matrix material
Ni th
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essfu
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uperallo
ys
Ni-base superalloys
WROUGHT DS/SX PM/ODS
Astroloy
Hastelloy X
Inconel 718
Nimonic
Udimet 500
Rene N4 MA 6000
General Applications
Load bearing
structures at
high ThomGas turbines
Rocket engines
Submarines
Nuclear reactors
Chemical processing
vessels
Heat exchanger
tubing
Ni-base superalloysintroduction to selected alloy series
Inconel alloys
high oxidation resistance
ability to maintain their structural integrity in high temperature atmosphere resistance against caustic corrosion
resistance against corrosion caused by high purity water
resistance against stress-corrosion cracking
General remarks
Major application:
CHEMICAL INDUSTRY
Inconel 738
precipitation-hardenable
nickel-chromium alloy
Fe, Mo and Nb additions,Ti and Al
(trace elements)
good weldability
resistant to post-weld cracking
maintain its structure in both high-
temperature and aqueous environments superb creep-rupture strength at
temperatures as high as 700°C
Applications
Spacecrafts
Nuclear reactors
Rocket motors
Ni-base superalloys
introduction to selected alloy series
Hastelloys
General remarks
one of the best corrosion resistants
(among Ni-base S.A.)
high resistance in chemical and
oxidizing applications
one of the world's toughest materials
pitting and cracking resistant
high-temperature strength in vacuums and atmospheres that are chemically inert
Hastelloy X
one of the world's most popular alloys uncommon resistance to oxidation exceptional heat resistance and
fabricability
good ductility
good price
Applications
gas turbine engines
flame holders industrial furnaces
Rotary Dryer
Ni-base superalloys
introduction to selected alloy series
Monel
General remarks
developed by Robert Crooks Stanley who worked for the International Nickel Company (INCO) in 1901
The new alloy was named in honor of the president of the company, Ambrose Monell is based on nickel (65-70%) and copper (20- 29%) and also contains iron and manganese (5%) and other compounds Standard product forms are round, hexagon, flats, forging stock, pipe, tube, plate, sheet, strip, and wire
stronger than steel
malleable
low coefficient of thermal expansion
highly resistant to alkalis
able to be welded,
brazed and soldered
Applications
Pump shafts
Impellers
Blades and scrapers
oil-well drill instruments
springs
Valve trim
Propeller
valve
components
for ships
centrifugal pumps
in the
marine industrykitchen
sinks
frames of eyeglasses
Golf
Some notes…
Superalloys or high-performance alloys, are the materials able to withstand extreme temperatures that would destroy conventional metals like steel and aluminum The widespread use of superalloys in turbine engines
coupled with the fact that the thermodynamic efficiency of turbine engines is increased with increasing turbine inlet temperatures
To avoid surface attack (due to the presence of reactive alloying elements) including oxidation, hot corrosion, and thermal fatigue,in the most demanding applications, such as turbine blade and vanes, superalloys are often coated to improve environmental resistance.
and…..
having a quick look into the wide range having a quick look into the wide range ofof
superalloys’ applications, shows that superalloys’ applications, shows that these materials have been affecting the these materials have been affecting the
human life, from within the human body to human life, from within the human body to the spacecrafts, and from power the spacecrafts, and from power
generation plants to almost any field which generation plants to almost any field which may need a stable, strong and may need a stable, strong and
environmentally resistant material, for half environmentally resistant material, for half a century!!a century!!
THANK YOU!