Development of a new corrosion resistant Ni-Cr-Mo-Ta alloy with improved corrosion resistance to sulfur dewpoint corrosion

Conference · Thu Aug 01 00:00:00 EDT 1996

OSTI ID:271993

Sugahara, Katsuo; Takizawa, Yoshio ^[1]

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1. Mitsubishi Materials Corp., Omiya, Saitama (Japan). Central Research Inst.

In the operation of most power plants, waste heat of flue gases from heavy oil-fired or coal-fired boilers is recovered by economizers and preheaters. These flue gases contain N{sub 2}, O{sub 2}, H{sub 2}O, CO{sub 2}, SO{sub 2}, SO{sub 3}, NO{sub x}, HCl, unburned carbon and fly ashes. The temperatures of the flue gases, which are basically kept at temperatures higher than 200 C, are controlled above the sulfuric acid dewpoint. A new corrosion resistant Ni-Cr-Mo-Ta alloy has been developed with improved corrosion resistance to sulfur dewpoint corrosion. The corrosion tests show that this alloy can be used for heat-exchangers to recover waste heat at low temperatures in fossil fuel-fired power plants. This new alloy, which is composed of 20% chromium, 20% molybdenum, 2% tantalum and balance nickel, shows excellent corrosion resistance to sulfur dewpoint corrosion. The general and localized corrosion resistance behavior of this new alloy has been tested in different candidate solutions such as sulfuric acid solutions with and without active carbon powder, sulfuric-hydrochloric acid mixtures, ASTM G-28 Method B, and Green Death solution. Very excellent corrosion resistance performance against these tests has been shown in the laboratory. Moreover the corrosion resistance of welded joints does not degrade in the as welded condition.

• OSTI ID: 271993
• Report Number(s): CONF-960389-; TRN: IM9635%%420
• Resource Relation: Conference: National Association of Corrosion Engineers (NACE) annual corrosion conference and exposition: water and waste water industries, Denver, CO (United States), 24-29 Mar 1996; Other Information: PBD: 1996; Related Information: Is Part Of Corrosion/96 conference papers; PB: [6615] p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
20 FOSSIL-FUELED POWER PLANTS
01 COAL, LIGNITE, AND PEAT
02 PETROLEUM
NICKEL BASE ALLOYS
CORROSION RESISTANCE
CHROMIUM ALLOYS
MOLYBDENUM ALLOYS
TANTALUM ALLOYS
HEAT RECOVERY EQUIPMENT
CORROSION RESISTANT ALLOYS
FLUE GAS
HEAT RECOVERY
FOSSIL-FUEL POWER PLANTS
COAL
FUEL OILS
COMBUSTION
SULFUR COMPOUNDS
CORROSIVE EFFECTS
MEASURING METHODS
STAINLESS STEEL-316L
COMPARATIVE EVALUATIONS