Status of titanium blading for low-pressure steam turbines. Final report. [Ti-6Al-V alloys]

Technical Report · Tue Feb 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/7212061· OSTI ID:7212061

Wood, R. A.

Titanium is of interest for blading the last stages of low-pressure steam turbines. It is stronger, lighter and more corrosion and erosion resistant than the standard 12Cr steel which has been used for blading for many years. A possible disadvantage of titanium blading is its low damping capacity, which requires careful design to tune out resonant vibrations that might be encountered in service, and the use of mechanical damping using shrouds and lashing wires. The lower density of titanium permits longer blades to be used for last stage rows, which would be useful in very large units. The lower density of titanium also results in lower stresses on the attachment to discs or shafts, reducing their susceptibility to stress corrosion cracking. Because of the above attributes of titanium, a survey was conducted by Battelle Columbus to summarize the worldwide status of titanium blading in the low pressure steam turbine. It is shown that steam turbine makers all over the world are considering the use of titanium blades, particularly for larger turbines, but also for present size turbines because of better corrosion resistance. Titanium blading appears close to being introduced into production steam turbines, particularly in Western Europe, and are in standard production in the Soviet Union. In the United States, titanium blades are being evaluated for last stage and next-to-last stage rows on a limited basis, and are routinely used for closing blade applications. EPRI is using this information as guidance for R and D on titanium blading. A current project, RP912 with Westinghouse, is evaluating the corrosion fatigue resistance of Ti-6Al-4V alloy in steam.

• Research Organization: Battelle Columbus Labs., OH (USA)
• OSTI ID: 7212061
• Report Number(s): EPRI-AF-445
• Country of Publication: United States
• Language: English

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ASIA
CORROSION FATIGUE
COST
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EUROPE
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JAPAN
MECHANICAL PROPERTIES
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VANADIUM ALLOYS