Effect of hot corrosion on the creep behavior of stainless steels

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:233951

Gonzalez-Rodriquez, J G; Salinas-Bravo, V M; Luna-Ramirez, A ^[1]; Martinez-Villafane, A ^[2]

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1. Inst. de Investigaciones Electricas, Morelos (Mexico)
2. Centro de Investigaciones En Materiales, Chihuahua (Mexico)

Problems caused by both hot corrosion and creep type damage occurring on superheater and reheater tubes of power plants using heavy oil as fuel, inhibit the continuous service of the boilers and shorten their design lives. The acceleration of hot corrosion attack of boilers is caused by the presence of fuel ash deposits containing mainly V, Na and S, in the form of Na{sub 2}SO{sub 4} and V{sub 2}O{sub 5}, which form low melting point compounds. In addition to this, the tubes are exposed to the action of both high stresses and high temperatures, producing a continuous plastic deformation on the tube walls, the so called ``creep damage``. In order to predict the creep lives of 321H and 347H type stainless steels used in superheater and reheater tubes under hot corrosion and creep environments, creep rupture tests were carried out in the temperature range 620 to 670 C in static air with the presence of corrosive environments. The corrosive environment include synthetic Na{sub 2}SO{sub 4}, V{sub 2}O{sub 5} and the mixture 80%V{sub 2}O{sub 5}+20%Na{sub 2}SO{sub 4}. Also, the role of the different elements present in the environments on corrosion was investigated using electronic microscopy and X-ray diffraction techniques.

• OSTI ID: 233951
• Report Number(s): CONF-950908--; ISBN 0-87170-539-7
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
36 MATERIALS SCIENCE
BOILERS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CORROSION
CREEP
EXPERIMENTAL DATA
FOSSIL-FUEL POWER PLANTS
FRACTURES
GRAIN BOUNDARIES
IRON BASE ALLOYS
MANGANESE ALLOYS
METALLOGRAPHY
MOLYBDENUM ADDITIONS
NICKEL ALLOYS
NIOBIUM ADDITIONS
SILICON ADDITIONS
SODIUM SULFATES
TEMPERATURE DEPENDENCE
TITANIUM ADDITIONS
VANADIUM OXIDES
X-RAY DIFFRACTION