Investigation of S-N Test Data Scatter of Carburized 4320 Steel

2007-01-1006

04/16/2007

Event
SAE World Congress & Exhibition
Authors Abstract
Content
A series of bending fatigue tests were conducted and S-N data were obtained for two groups of 4320 steel samples: (1) carburized, quenched and tempered, (2) carburized, quenched, tempered and shot peened. Shot peening improved the fatigue life and endurance limit. The S-N data exhibited large scatter, especially for carburized samples and at the high cycle life regime. Sample characterization work was performed and scatter bands were established for residual stress distributions, in addition to fracture and fatigue properties for 4320 steel. Moreover, a fatigue life analysis was performed using fracture mechanics and strain life fatigue theories. Scatter in S-N curves was established computationally by using the lower bound and upper bound in materials properties, residual stress and IGO depth in the input data. The results for fatigue life analysis, using either computational fracture mechanics or strain life theory, agreed reasonably well with the test data. However, the scatter in the fatigue properties of the material and the scatter in residual stress could not fully account for the large scatter in fatigue life. Other factors that might be considered for root causes of the observed large fatigue life scatter were identified and discussed.
Meta TagsDetails
DOI
https://doi.org/10.4271/2007-01-1006
Pages
15
Citation
Lin, H., Fett, G., Binoniemi, R., Sanders, J. et al., "Investigation of S-N Test Data Scatter of Carburized 4320 Steel," SAE Technical Paper 2007-01-1006, 2007, https://doi.org/10.4271/2007-01-1006.
Additional Details
Publisher
Published
Apr 16, 2007
Product Code
2007-01-1006
Content Type
Technical Paper
Language
English