K. Kimakh et alii, Frattura ed Integrità Strutturale, 48 (2019) 429-441; DOI: 10.3221/IGF-ESIS.48.41 429 Experimental investigation of surface roughness effect on fatigue performance of AISI 1045 carbon steel and fatigue limit prediction Khadija Kimakh, Abdelkerim Chouaf, Amal Saoud, El Hassan Mallil Hassan II University, National Superior School of Electricity and Mechanics Casablanca (ENSEM), LCCMMS, Morocco. khadija.kimakh@gmail.com, http://orcid.org/ 0000-0002-2418-1307 a.chouaf.ensem@gmail.com, http://orcid.org/ Saoudamal22@gmail.com http://orcid.org/ 0000-0002-2139-2627 Samir Aghzer Hassan II University, Superior School of Technology Casablanca (EST), LCCMMS, Morocco. ABSTRACT. In fatigue life, surface integrity perform a major role to determine the fatigue lifetime. It could differ greatly among specific cases even for the same solicitations. Indeed, the manufacturing process carries modifications on surface state, residual stresses and the microstructure which affects the fatigue behavior of mechanical parts. This article investigate the effect of surface roughness on the fatigue strength of AISI 1045 carbon steel obtained by the turning process. The work carried out consists in testing in uniaxial fatigue different batches of specimens which have a controlled surface state. The S-N curves obtained present a strong dependence between fatigue performance and surface state. Based on the surface topography, a model for predicting fatigue limit will be adopted. KEYWORDS. Fatigue; Surface roughness; Turning condition; Fatigue limit. Citation: Kimakh, K., Chouaf, A., Saoud, A., Mallil, E.-H., Aghzer, S., Experimental investigation of surface roughness effect on fatigue performance of AISI 1045 carbon steel and fatigue limit prediction, Frattura ed Integrità Strutturale, 48 (2019) 429-441. Received: 21.12.2018 Accepted: 22.02.2019 Published: 01.04.2019 Copyright: © 2019 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. INTRODUCTION he fatigue behavior of materials is a major issue which interest the designers and manufacturers. Their main motivation is to obtain components with a low cost and a long fatigue life time, the latter is affected by many parameters. The manufacturing process is one of the influencing factors. Indeed, it generates modifications on the surface integrity, namely the microstructure, the residual stresses and the surface state. Therefore several researchers have been interested to study the influence of surface integrity on fatigue behavior. They showed that all the cutting parameters affect significantly the results obtained during a machining operation. This generates changes in surface integrity and consequently fatigue behavior [1, 2]. Based on different analytical or experimental models, several studies have highlighted the impact of topography and surface integrity on fatigue behavior of materials. Unfortunately, these models don’t consider all influencing factors. T