Comparison of low cycle fatigue behavior of 316 and 316LN stainless steels in 310oC water

Abstract

The low cycle fatigue (LCF) behavior of stainless steels in 310oC water was investigated. LCF life was somewhat shorter for 316LN compared to 316 SS at similar loading conditions. For 316 SS, the cyclic hardening response was greater, while the crack tip blunting was smaller compared to 316LN. The fatigue surface observation and microstructure analysis indicated that hydrogen induced cracking (HIC) would be the dominant mechanism of environmental effects. The different LCF life in 310oC water was discussed in view of the cyclic hardening, dislocation structure near crack tip, role of HIC, and composition of both SSs.