Fatigue Life of Superalloy Haynes 188 in Hydrogen
Autor: | John Gayda, Timothy T. Gorman, Tim Gabb, Greg Ribeiro, Henry Webster |
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Rok vydání: | 2011 |
Předmět: | |
Zdroj: | Journal of Materials Engineering and Performance. 21:1687-1695 |
ISSN: | 1544-1024 1059-9495 |
DOI: | 10.1007/s11665-011-0067-1 |
Popis: | The effects of hydrogen and surface finish on the mean low cycle fatigue life of Haynes 188 were studied. Specimens were prepared and fatigue tested with gage sections having low stress ground (LSG) and electro-discharge machined (EDM) surfaces. Fatigue tests were performed at temperatures of 25 to 650 °C with varied strain conditions, in hydrogen and helium environments. Fatigue life decreased with increasing strain range, strain ratio, temperature, and with hydrogen atmosphere. A Smith-Watson-Topper stress parameter could be used to account for variations in strain range and strain ratio, and most strongly influenced life. Hydrogen reduced fatigue life by about 5× (80%) at 25 °C, but was much less harmful at 650 °C. Standard EDM finish did not consistently reduce mean fatigue life from that of LSG finish specimens. Additional tests indicated fatigue life in hydrogen was maintained for varied EDM conditions, provided specimen roughness and maximum recast layer thickness were not excessive. |
Databáze: | OpenAIRE |
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