14th International Conference on Shot Peening

Application Of Laser Shock Peening On Nitrided Steel For Power Transmission Components

M. Guerboisa,b, C. Didesb, A.Bonninc, L. Berthea, and V. Faviera

Laboratoire PIMM, Arts et Metiers Institute of Technology, ENSAM, CNRS, CNAM, HESAM Université, 151 Boulevard de l’Hôpital, 75013 Paris, France, bInstitut de Recherche Technologique Matériaux, Métallurgie et Procédés, 4 Rue Augustin Fresnel, 57070 Metz, France cAirbus Helicopters Contacts : maxime.guerbois@irt-m2p.fr , corentin.dides@irt-m2p.fr,alexandre.bonnin@airbus.com , laurent.berthe@cnrs.fr , veronique.favier@ensam.eu

Introduction

In the frame of transmission components features, gear teeth root load-carrying capacity is one of the key factors in gear design. That is why state of the art on such component regarding materials /processes are thermochemical treatments, enhanced eventually by shot peening post-treatment to enhance fatigue lifetime. Because of the high hardness of nitrided surface introducing additional compressive residual stresses with conventional shot peening request specific conditions and shots. Laser Shock Peening (LSP) technology generate very high pressure on material surface and so introduce higher and deeper compressive residual stress. Today, most of study about laser peening are performed on aluminium or titanium alloys. In this study, samples were 32-CrMoV-13 deep Nitrided steel. The study aim was to identify material behaviour regarding laser peening parameters. This study is performed in the frame of IRT M2P TRANSFUGE project, which aims to study innovative material and treatment for gear parts.

Objectives

The 32-CrMoV-13 deep Nitrided steel studied has high surface hardness (~800HV), and compressive residual stresses deep into treated material. Introducing additional compressive residual stresses (RS) require an adapted set of LSP parameters. The main goal of this study consists in finding a set of LSP parameters allowing the surface and sub surface compression residual stress enhancement with a minimum impact on surface morphology and roughness; and without impact on nitrided material metallurgic features (hardness, microstructure in particular)