Papers by Author: Yuji Fukuda

Abstract: Fe-Si intermetallic thermal spray powders have been developed for sulfidation corrosion and erosion protection for furnace walls in pulverized coal fired boiler. In this paper, evaluation of corrosion and erosion resistance of developed coatings was performed. The corrosion test results showed that the developed coatings almost equal corrosion resistance to conventional corrosion resistant coatings under the low NOX boiler condition. Erosion test results also indicated that Fe-20Si-1B using atmospheric plasma spraying showed higher erosion resistance than the conventional coatings.

Abstract: Japanese government project of the A-USC technology was started in 2008 August. 700°C class boiler, turbine and valve technologies, which include high temperature material technology, will be developed. This report provides the present state of the art and technical background of this development effort for A-USC in Japan, especially focusing the high temperature corrosion and the steam oxidation behavior of available and developmental materials for boiler.

Abstract: Achieving higher plant efficiency in thermal power plants is one of the major global challenges from the viewpoint of reducing carbon dioxide emission levels, particularly in coal-fired boilers, irrespective of the type of coal being burned. In recent times, it has been possible to increase the steam temperature in coal fired ultra supercritical (USC) plants without too much of a cost impact. The temperature has already been increased to 600
for main steam and 610
for reheat steam. The main enabling technology is the development of stronger high temperature materials such as newly developed high Cr ferritic steels and austenitic steels, capable of operating under high stresses at increasing high temperatures. Other key demands for those materials are hot corrosion resistance such as coal ash corrosion in superheater and reheater tubes and sulfidation of waterwall tubes, and steam oxidation resistance. This paper will mainly present the hot corrosion and steam oxidation properties of newly developed high strength heat resistant steels for their application to USC boilers and long-term experience in an actual plant.