Peening

About: Peening is a research topic. Over the lifetime, 5538 publications have been published within this topic receiving 73073 citations.

The effect of shot peening on fatigue and corrosion behavior of 316L stainless steel in Ringer's solution

Abstract: Stainless steel 316L is one of the most common biomaterials utilized for producing orthopedic implants. But it has low resistance to fatigue and wear. Therefore surface treatments such as shot peening are used to modify the surface properties. In the present research, the influence of shot peening treatment on hardness, fatigue and corrosion behavior of 316L stainless steel in Ringer's solution was investigated. For this purpose, the steel specimens were shot peened for 5, 10, 15, 20 and 25 min. Hardness, fatigue and electrochemical tests were performed on each specimen before and after shot peening treatment. The open circuit potential (OCP) of the specimens, after 2 h of equilibrium time, was measured in Ringer's solution for 300 s. The cyclic potentiodynamic polarization tests were performed with 5 mV/s scan rate. According to the results, the shot peening treatment increases the surface hardness and fatigue resistance. In addition, this treatment decreases the break-down potential of the passive layer and increases the corrosion current density in shot peened specimens up to 10 min, which shows a reduction in resistance to pitting corrosion. However, the break-down potential of the passive layer begins to increase and the corrosion current density decreases at upper times. This trend continues such that even the conditions of resistance to pitting corrosion improve in comparison with un-shot peened specimens at longer times of shot peening. The morphology of the fractured surfaces of samples was investigated by scanning electron microscopy (SEM).

Laser shock peening for gas turbine engine vane repair

Abstract: A wide gap braze repair, particularly for a gas turbine engine vane or a component in the hot section of the engine. The repair is characterized by a braze filled void in a damaged area of the component, a laser shock peened surface over the repaired area of the braze filled void, and a region of deep compressive residual stresses imparted by laser shock peening (LSP) extending from the laser shock peened surface into the repair.

Comparison between shot peening and surface nanocrystallization and hardening processes

Abstract: The surface nanocrystallization and hardening (SNH) is a relatively new process that has been developed to enhance fatigue and wear resistances. The SNH is similar to widely used shot peening (SP) in the sense that both processes entail repeated impacts of the work-piece surface with spheres. The difference between them lies in the sizes of spheres and the impact velocities used. Such a difference results in dramatic changes in kinetic energies and thus the thicknesses of the work-hardened layer and the nano-grained surface layer. In this study, finite element modeling is performed to provide quantitative description of these differences. The results show that the kinetic energy in the SNH process is typically 180 times larger than that in shot peening, and the deformation layer in the SNH process is about 10 times thicker than that generated in shot peening. Furthermore, the maximum plastic strain and the maximum residual compressive stresses in the SNH-processed work-piece are 100 and 10 times larger than those in the shot-peened work-piece, respectively. The implication of these differences on fatigue resistance has been discussed.