Volume 20, Issue 6 (November 1992)
Crack Initiation and Total Fatigue Life of a Carbon Steel in Vacuum and Air
Fully-reversed strain-controlled test results of a carbon steel (ASTM A 516 Gr. 70) in an ambient atmosphere and in a vacuum of 0.1 mPa are compared. Vacuum data may be viewed as representing a “pure” (mechanical) fatigue damage. In the case of an air environment, the rate of fatigue damage accumulation increases due to the environmental contribution.
The test results are described in terms of the crack initiation and total lives. The crack initiation data are fairly well-correlated with the plastic strain energy per cycle. The significance of the environment condition on the life prediction procedures is discussed.