Volume 37, Issue 3 (May 2009)
Effects of Cycles below the Fatigue Limit on the Life of a High Strength Steel
The objective of this work was to study the hypothesis of the possible influence of stress ranges below the fatigue limit on the fatigue life of the material. The experiments were conducted on high strength steel (Uddeholm Impax Supreme®, a CrNiMo steel) with tension-tension periodic blocks under stress control. The fatigue limit of the steel for tension-tension was determined by the staircase method. The programmed loading contained one repeated sequence of two ranges of stress cycles, above and below the fatigue limit. One-sided t-testing showed that it cannot be concluded that there is a significant influence of the range of stress below the fatigue limit on the fatigue life of the material, although a slight beneficial effect was indicated.