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Lawrence, Frederick V., Jr Ahn, Seung-Ho 2011-05-07T12:06:36Z 2011-05-07T12:06:36Z 10000-01-01 1990 Single-pitted specimens of HF-80, a HSLA steel, were tested in laboratory air and in 1 M NaCl solution to study the influence of a corrosive environment on its fatigue life. The growth of fatigue cracks and the partitioning of the fatigue life into fatigue crack initiation and fatigue crack propagation were studied by photographing the pit and the cracks developing on it periodically during testing. Non-propagating or dormant surface cracks were not observed in this study. Fractography using SEM showed the locations of fatigue crack initiation. The mechanisms of corrosion fatigue were studied by performing tests in 1 M NaCl at different test frequencies. Corrosion pits proved to be crack initiation sites. Hydrogen embrittlement was found to be insignificant in the corrosion fatigue of HSLA steel in this study. The 1 M NaCl corrosive environment appeared to reduce the fatigue life of this material by a dissolution mechanism. The effect of pit depth was studied by testing specimens having various pit depths. An effect of pit size was apparent. Fatigue life decreased with increasing pit depth. Pit depth, rather than the ratio of pit depth to pit diameter, influenced fatigue behavior. A non-damaging pit depth was found. Made available in DSpace on 2011-05-07T12:06:36Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9021645.pdf: 2485769 bytes, checksum: 4293cde3de93a69629c8d5a4e2045802 (MD5) Previous issue date: 1990 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:36:45Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:14:56-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9021645 (UMI)AAI9021645 http://hdl.handle.net/2142/19408 eng Copyright 1990 Ahn, Seung-Ho Engineering, Materials Science The influence of environment on the fatigue behavior of HF-80 HSLA steel text Materials Science and Engineering Metallurgical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.