Potential Improvements of Mechanical Properties of Maraging Steels After Laser Shock Peening
L. Petan, J. Ocaña, J. Porro and J. Grum
Maraging steels represent a special group of precipitation-hardening steels, mainly used for highly stressed components in critical applications and for the manufacturing of die casting tools. Consequently, they are subject to different forms of load and wear which inevitably shorten their service life. Therefore, improvements of their mechanical properties and especially the resistance of the surface layer to such phenomena are of great interest. Peening techniques, such as shot peening (SP) and laser shock peening (LSP), represent a promising solution. In this paper, we present the results obtained with the surface integrity analysis on X2NiCoMo18-9-5 maraging steel before and after different sequences of LSP and heat treatment stages. The originality of the present work is that the laser treatment has been performed on a maraging steel, which brings new insights into the effects on its fatigue strength, which could be of interest to the scientific community and the industry. The main challenge is the optimization of process parameters using affordable low energy lasers. Within the present study LSP has shown promising results, supported by mechanical fatigue tests.
Keywords: Fatigue strength; laser shock peening (LSP); maraging steels; precipitation hardening; roughness; residual stress