Gigacycle Fatigue Crack Initiation in Cr-Mo Prealloy Sintered Steel


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Crack initiation and short crack propagation was studied on the polished notched surfaces of Cr-Mo prealloy sintered steels with 7.35 sintered density. An ultrasonic resonance test system operating in push-pull mode at 20 kHz and R=-1 was used. It showed that crack initiation took place in several places, small cracks growing oriented to the local pore structure rather than to stress orientation. Their growth rate is markedly higher than the corresponding one of long cracks. Finally, several microcracks join to form a dominant crack.



Materials Science Forum (Volumes 534-536)

Edited by:

Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim




C. Xu et al., "Gigacycle Fatigue Crack Initiation in Cr-Mo Prealloy Sintered Steel ", Materials Science Forum, Vols. 534-536, pp. 685-688, 2007

Online since:

January 2007




[1] C.M. Sonsino, Fatigue Concept Design, Metal Powder Industry (2003).

[2] O. Mårs et al, Proc. DF PM'99 Deformation and Fracture in Structural Materials. IMR SAS Kosice, 1999, p.53.

[3] A. Bergmark, Proc. PM2Tec2001 New Orleans, MPIF, Princeton NJ (2001), on CD.

[4] A. Bergmark et al, Fatigue crack initiation in PM steel, PM2Tec2002 Orlando (2002) pp.5-95.

[5] J.R. Moon, Powder Metall. Progress Vol. 2 No. 2 (2002) p.63.

[6] J.R. Moon, Proc. DF PM2005, Stara Lesna, Slovakia (2005) p.138.

[7] P. Beiss, Pulvermetallurgie in Wiss. & Praxis Vol. 19, H. Kolaska ed. (2003) p.3.

[8] H. Danninger, B. Weiss, Powder Metall. Progress Vol. 1 No. 1 (2001) p.19.

[9] Roth, L.D., Ultrasonic fatigue testing, in: Metals Handbook Vol. 8, 9 th ED., ASM, Metals Park OH (1985).

[10] B. Weiss, R. Stickler, A. Fathulla, Initiation and transition of short to long fatigue cracks in technical alloy, in Proceedings of the Second Engineering Foundation Conference on Small Fatigue Cracks, R.O. Ritchie and J. Lankford ed., Santa Barbara, Calif. (1986).

[11] S. Suresh, R. O Ritchie, Propagation of short. fatigue cracks, Int. Metals Rev. 29, (1984) p.445.