TY - CONF
T1 - High temperature corrosion of gradient tubes for high temperature application
AU - Yli-Olli, Sanni
AU - Isotahdon, Elisa
AU - Tuurna, Satu
AU - Brziak, Peter
AU - Mahanen, Jouni
N1 - Funding Information:
For competitive low carbon or carbon neutral combustion, future boilers will need to utilize an increasing amount of biomass. The resulting combustion environment poses a challenge by contain large amounts of severely corrosive constituents that attack existing materials and might drastically limit their durability and lifetime. New structural materials can be attractive in principle, but it has been challenging to simultaneously achieve good mechanical strength, high temperature corrosion/oxidation resistance and cost-effective composition in the candidate alloys. To avoid undue loss of thermal efficiency or facing an increasing number of unscheduled outages new solutions in protecting the existing material (by coatings and overlay welds) need to be developed. Newly developed creep resistant gradient tubes with increased fireside corrosion resistance, have shown good performance for the elevated conditions. Gradient tubes, made of 11CrMo9-10 low alloy body and 347H austenitic shell, are oriented for boilers burning aggressive flue gases/ashes producing feedstock, e.g. biomass/chip/straw boilers. The paper describes the high temperature corrosion resistance of the gradient tubes in accelerated laboratory scale tests and long term on-site tests in real boiler conditions. The results show that the thickness and microstructural state of the austenite layer as well as possible surface defects of the gradient tube have a great influence on the high temperature corrosion rate of the gradient material. Overall, the new material shows comparable performance to the conventional 347H material. The work was done within the GRAMAT project supported by EU Research Fund for Coal and steel. The main aim of project is to acquire knowledge necessary to develop new cost-effective manufacturing technology of boiler tubes made from semi products with through thickness gradient chemical composition, tailored to carry both creep loading (low alloyed body) and fireside corrosion resistance (high alloyed shell).
Publisher Copyright:
© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - For competitive low carbon or carbon neutral combustion,
future boilers will need to utilize an increasing amount
of biomass. The resulting combustion environment poses a
challenge by contain large amounts of severely corrosive
constituents that attack existing materials and might
drastically limit their durability and lifetime. New
structural materials can be attractive in principle, but
it has been challenging to simultaneously achieve good
mechanical strength, high temperature corrosion/oxidation
resistance and cost-effective composition in the
candidate alloys. To avoid undue loss of thermal
efficiency or facing an increasing number of unscheduled
outages new solutions in protecting the existing material
(by coatings and overlay welds) need to be developed.
Newly developed creep resistant gradient tubes with
increased fireside corrosion resistance, have shown good
performance for the elevated conditions. Gradient tubes,
made of 11CrMo9-10 low alloy body and 347H austenitic
shell, are oriented for boilers burning aggressive flue
gases/ashes producing feedstock, e.g. biomass/chip/straw
boilers. The paper describes the high temperature
corrosion resistance of the gradient tubes in accelerated
laboratory scale tests and long term on-site tests in
real boiler conditions. The results show that the
thickness and microstructural state of the austenite
layer as well as possible surface defects of the gradient
tube have a great influence on the high temperature
corrosion rate of the gradient material. Overall, the new
material shows comparable performance to the conventional
347H material.
The work was done within the GRAMAT project supported by
EU Research Fund for Coal and steel. The main aim of
project is to acquire knowledge necessary to develop new
cost-effective manufacturing technology of boiler tubes
made from semi products with through thickness gradient
chemical composition, tailored to carry both creep
loading (low alloyed body) and fireside corrosion
resistance (high alloyed shell).
AB - For competitive low carbon or carbon neutral combustion,
future boilers will need to utilize an increasing amount
of biomass. The resulting combustion environment poses a
challenge by contain large amounts of severely corrosive
constituents that attack existing materials and might
drastically limit their durability and lifetime. New
structural materials can be attractive in principle, but
it has been challenging to simultaneously achieve good
mechanical strength, high temperature corrosion/oxidation
resistance and cost-effective composition in the
candidate alloys. To avoid undue loss of thermal
efficiency or facing an increasing number of unscheduled
outages new solutions in protecting the existing material
(by coatings and overlay welds) need to be developed.
Newly developed creep resistant gradient tubes with
increased fireside corrosion resistance, have shown good
performance for the elevated conditions. Gradient tubes,
made of 11CrMo9-10 low alloy body and 347H austenitic
shell, are oriented for boilers burning aggressive flue
gases/ashes producing feedstock, e.g. biomass/chip/straw
boilers. The paper describes the high temperature
corrosion resistance of the gradient tubes in accelerated
laboratory scale tests and long term on-site tests in
real boiler conditions. The results show that the
thickness and microstructural state of the austenite
layer as well as possible surface defects of the gradient
tube have a great influence on the high temperature
corrosion rate of the gradient material. Overall, the new
material shows comparable performance to the conventional
347H material.
The work was done within the GRAMAT project supported by
EU Research Fund for Coal and steel. The main aim of
project is to acquire knowledge necessary to develop new
cost-effective manufacturing technology of boiler tubes
made from semi products with through thickness gradient
chemical composition, tailored to carry both creep
loading (low alloyed body) and fireside corrosion
resistance (high alloyed shell).
KW - gradient tubes
KW - high temperature corrosion
KW - on-site testing
KW - biomass
KW - Gradient tubes
KW - Biomass
KW - On-site testing
KW - High temperature corrosion
UR - http://www.scopus.com/inward/record.url?scp=85052280885&partnerID=8YFLogxK
M3 - Conference article
T2 - 20th International Corrosion Congress & Process Safety Congress 2017, Eurocorr 2017
Y2 - 3 September 2017 through 7 September 2017
ER -