Open Access

ARTICLE

Fatigue Crack Growth Behaviour of Nitrided and Shot Peened Specimens

by C. Colombo¹, M. Guagliano¹, L. Vergani¹

1 Politecnico di Milano, Dipartimento di Meccanica
2 Corresponding author: Tel.: 02.2399.8206; Fax.: 02.2399.8202; E-mail: mario.guagliano@polimi.it Extended version of the paper presented at the Conference “Fracture and Damage Mechnics IV”, Mallorca, July 12-14, 2005

Structural Durability & Health Monitoring 2005, 1(4), 253-266. https://doi.org/10.3970/sdhm.2005.001.253

Abstract

In this paper the fatigue crack growth properties of a nitrided and shot-peened steel is dealt with: different peening intensities were considered and the resulting residual stresses measured by means of an X-ray diffractometer. Rotating bending fatigue tests were executed on specimens including a blind micro hole, acting as a pre-existent crack. The fracture surface of broken specimens was observed with a SEM to detect the crack growth initiation point. The run-out specimens were broken after the test and the presence of non-propagating cracks detected. The results allowed to determine the propagation threshold of the nitrided and shot peened material.

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Keywords

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