Notch Fatigue Properties of TRIP-Aided Annealed Martensitic Steels
Fatigue properties of TRIP-aided annealed martensitic steels with chemical composition of 0.2%C, 1.5%Si, 1.5%Mn, 0-1.0%Cr, 0-0.2%Mo, 0-0.05%Nb, 0-18ppmB was examined for application of automotive diesel engine common rail. The steels achieved extremely higher notch fatigue limits and lower notch-sensitivity than the conventional structural steels, especially in steel with boron or without chromium and molybdenum. This was associated with (i) the TRIP effect of a large amount of stable retained austenite and (ii) strain-induced transformed hard martensite which suppressed the crack initiation and growth due to plastic relaxation.
Sihai Jiao, Zhengyi Jiang and Jinglong Bu
N. Yoshikawa et al., "Notch Fatigue Properties of TRIP-Aided Annealed Martensitic Steels", Advanced Materials Research, Vols. 146-147, pp. 437-440, 2011