Very high cycle fatigue behaviors of Mn–Si–Cr series Bainite/Martensite dual phase steels

The present work studied the very high cycle fatigue (VHCF) behaviors of Mn-Si-Cr series Bainite/Martensite (B/M) dual phase high-strength low-alloy (HSLA) steels to ensure safe applications in railway and oil field. Four kinds of chemical compositions and seven types of B/M steels were designed and studied by ultrasonic fatigue test. The conception of apparent and intrinsic VHCF strength is addressed. Results show the effect of heat generation cannot be ignored in B/M steels in ultrasonic fatigue test, and higher is the intrinsic VHCF strength of materials, more remarkable is the negative effect of self-heating. More importantly, the VHCF property of B/M steels is less sensitive to the inclusion than that of tempered martensite steels, and the amount of retained austenite puts little effect on the VHCF property. (C) 2010 Elsevier Ltd. All rights reserved.