ISSN:
1662-8985
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The demand for ultra supercritical (USC) power plants has increased due to the need forhigh thermal efficiency and reduced CO2 emissions. For turbine materials, high-cycle and lowcyclefatigue life at USC service temperatures are needed to verify material integrity due to theheat-up and cool-down process of power plant operation and due to turbine variations duringoperation. In this paper, fatigue characteristics for 9~12 Cr steels as candidate USC bucketmaterials were investigated. First, the fatigue life between DS2B2 and COST B2 steel werecompared. COST B2 is the commercial steel with improved high temperature properties by addingboron, and DS2B2 is the new steel developed by Doosan by adding Co and adjusting Mo and Wbased on the same Mo equivalent value (%wt. Mo + 1/2 %wt. W). DS2B2 steel was found to havelonger low cycle fatigue life than COST B2. Second, the effect of boron on fatigue life for bucketmaterials based on COST B2 steel was investigated. At room temperature, as boron contentincreased, low cycle fatigue life became superior, whereas, at 593oC the fatigue life was similar.For high cycle fatigue, as boron content increased, fatigue life increased due to the strengtheningeffect by the addition of boron
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/40/transtech_doi~10.4028%252Fwww.scientific.net%252FAMR.26-28.1141.pdf
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