Abstract
The mechanism of fatigue failure in the ultra-high cycle regime was studied using a martensitic stainless steel. The effect of internal hydrogen trapped by nonmetallic inclusions on high cycle fatigue behaviour has been discussed by Murakami et al. In order to investigate more in detail the mechanism of the elimination of the conventional fatigue limit and the influence of hydrogen trapped by inclusion, specimens with various artificial small defects were prepared. The fatigue failure of a specimen which contained an artificial hole occurred at Nf ≅108 from a nonmetallic inclusion which is smaller in size than the artificial small surface hole. In the case of the specimen containing two artificial holes connected with a fatigue crack, non-propagation crack was observed at the edge of the artificial hole, and the fatigue limit was in good agreement with the value predicted by the √area parameter model. In the case of the specimen whose fatigue crack originating at an inclusion, the crack continued propagation, and finally the specimen failed. Considering that nonmetallic inclusions trap hydrogen, it is presumed that the elimination of the conventional fatigue limit due to fatigue crack originated at nonmetallic inclusion is caused by synergetic effect of cyclic stress and hydrogen trapped by inclusions.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings of the 1992 Annual Meeting of JSME/MMD
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
