Numerical and experimental studies on needle impact characteristics in ultrasonic shot peening

In the nuclear industry surface mechanical treatments are used in order to improve the surface integrity of the component, which increases their lifetime regarding corrosion and fatigue damages. A good understanding of these processes and their consequences is required to ensure the efficiency and perpetuity of such mitigation treatment. This study focuses on the ultrasonic shot peening process. It consists in shooting at high speed small steel beads on the part to be treated by using a high frequency vibration device. Parameters such as the number and the size of beads, the input frequency and the dimensions of the chamber can induce large ranges of impact velocity and coverage. In order to help manufacturers to control the treatment applied on their components, a numerical model has been developed. It accounts for the shocks of the beads against the walls of the chamber, the peening head and between beads, describing their motions accurately. In this paper, we will introduce the numerical model developed to simulate the motions of beads in the peening chamber. Special attention will be taken to the determination of the restitution rates related to the different materials. Results of the model will be shown for different process parameter (e.g. the number of beads), and a thorough analysis of their effects on the workpiece will be presented, including a comparison with some experimental results.

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3D Model of Shot Dynamics for Ultrasonic Shot Peening

Materials Science Forum ◽

10.4028/www.scientific.net/msf.768-769.503 ◽

2013 ◽

Vol 768-769 ◽

pp. 503-509 ◽

Cited By ~ 1

Author(s):

Jawad Badreddine ◽

Emmanuelle Rouhaud ◽

Matthieu Micoulaut ◽

Sebastien Remy ◽

Vincent Desfontaine ◽

...

Keyword(s):

Residual Stress ◽

Process Parameters ◽

Spatial Data ◽

Shot Peening ◽

3D Model ◽

Prediction Models ◽

Dissipated Energy ◽

Displacement Fields ◽

Ultrasonic Shot Peening ◽

Stress Prediction

This paper presents a 3D model that simulates an ultrasonic shot peening (USP) operation, using realistic process parameters and peening setups (part and chamber geometries). By simulating the shot dynamics (shot trajectories and impacts), statistical and spatial data are obtained for the peened component, i.e. surface coverage and coverage rate, impact speeds and angles, dissipated energy... This data can then be used for i) optimizing the design of peening chambers and process parameters and ii) predicting the residual stress and displacement fields induced by USP in the peened component. In fact, data from the 3D model can be used as initial data in existing residual stress prediction models. A chaining methodology was developed for this purpose and allows linking the choice of process parameters and USP setup to the induced residual stress displacement fields.

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Surface nanocrystallization of 316L stainless steel induced by ultrasonic shot peening

Materials Science and Engineering A ◽

10.1016/s0921-5093(00)00686-9 ◽

2000 ◽

Vol 286 (1) ◽

pp. 91-95 ◽

Cited By ~ 328

Author(s):

G Liu ◽

J Lu ◽

K Lu

Keyword(s):

Stainless Steel ◽

Shot Peening ◽

316L Stainless Steel ◽

Surface Nanocrystallization ◽

Ultrasonic Shot Peening

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Some Aspects of Operated Blades HCF Analysis: Rejuvenation and Life Estimation

Volume 7A: Structures and Dynamics ◽

10.1115/gt2018-75731 ◽

2018 ◽

Author(s):

Sergey A. Ivanov ◽

Maxim G. Guralnik ◽

Alexander I. Rybnikov

Keyword(s):

Shot Peening ◽

Gas Turbines ◽

Turbine Blades ◽

Life Extension ◽

Ultrasonic Shot Peening ◽

Industrial Gas Turbines ◽

Hcf Strength ◽

Blade Failure ◽

Metal Properties ◽

The Cost

The lifecycle of modern industrial gas turbines can reach hundred thousand hours and usually the turbine blades need to be replaced. The use of super alloys and application of advanced coatings makes the cost of turbine lifecycle rather high. The methods for blade rejuvenation and life extension are based on the analysis of the main defects which can considerably reduce blade strength. The effect of long operation and typical defects in turbine blades has been studied in correlation with HCF. The decrease of blades HCF under the effect of operation has been considered as the result of influence of mechanical and thermal factors. The influence of FOD on the blade HCF strength is studied. Some random defects in turbine blades which resulted in HCF decreasing and blade failure are considered. The rejuvenation heat treatment for the blades of ZhS6K and EI893 and its positive effect on metal properties is demonstrated. The ultrasonic shot peening for operated blades have been considered. It is demonstrated that HCF strength of blades after shot peening is about 25–30% higher. Relaxation of compressing stresses in operation is shown as not essential. The remaining life of operated blades can be estimated using the correlation of endurance limit and run time.

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Effects of Laser Shock Peening and Ultrasonic Shot Peening on Fatigue Property of 1Cr11Ni2W2MoV Stainless Steel

Laser & Optoelectronics Progress ◽

10.3788/lop50.051403 ◽

2013 ◽

Vol 50 (5) ◽

pp. 051403 ◽

Cited By ~ 2

Author(s):

赖志林 Lai Zhilin ◽

汪诚 Wang Cheng ◽

李应红 Li Yinghong ◽

周留成 Zhou Liucheng ◽

何卫锋 He Weifeng ◽

...

Keyword(s):

Stainless Steel ◽

Shot Peening ◽

Fatigue Property ◽

Laser Shock Peening ◽

Laser Shock ◽

Ultrasonic Shot Peening ◽

Shock Peening

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Modelling of the Ultrasonic Shot Peening Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.490-491.67 ◽

2005 ◽

Vol 490-491 ◽

pp. 67-72 ◽

Cited By ~ 7

Author(s):

C. Pilé ◽

Manuel François ◽

Delphine Retraint ◽

Emmanuelle Rouhaud ◽

Jian Lu

Keyword(s):

Process Parameters ◽

Vibration Frequency ◽

Shot Peening ◽

Boltzmann Distribution ◽

Perfect Gas ◽

Average Speed ◽

Speed Distribution ◽

Almen Intensity ◽

Ultrasonic Shot Peening ◽

The Impact

The aim of this work is to reach a better understanding of the ultrasonic shot-peening process and, in particular, the evolution of the shot speed distribution. A simple 1D modelling of the interaction between the shots and the sonotrode is carried out. The impact is considered as inelastic with an energy absorption that depends on the speed of the shot. It is found that after about 10 interactions (» 1s) the speed distribution in the chamber follows a Maxwell-Boltzmann distribution, which is the distribution found in a perfect gas at equilibrium. The influence of various process parameters such as the sonotrode amplitude, the vibration frequency on the average speed and on the Almen intensity is studied.

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