Fundamentals of Hydrogen Embrittlement by Michihiko Nagumo

Author:Michihiko Nagumo
Language: eng
Format: epub
Publisher: Springer Singapore, Singapore

6.4 Delayed Fracture

Eventual failure in a long-term use under mild corrosive environments is a crucial problem for the structural components of high strength steels. Periods of service until fracture range to years. For laboratory tests, delayed fracture characteristics are expressed by the applied stress vs. time to fracture diagram similar to the S-N curve for fatigue tests. Accordingly, an alternate terminology for sustained-loading delayed fracture is “static fatigue”. Fracture mechanics test under sustained loading is a type of delayed fracture. The threshold stress intensity for the crack initiation K TH described in Sect. 6.2.1 for fracture mechanics tests corresponds to the lower limit of the applied stress below which delayed fracture does not occur, but notches are not requisite to induce delayed fracture. Delayed fracture diagrams vary by testing temperature, environment or hydrogen concentration, and specimen geometry. A long exposure time to fracture in practical services inevitably necessitates some accelerated tests in laboratories. The correspondence between practical and laboratory test results is a matter that needs careful examination.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.