VOL. 18 November ISSUE YEAR 2017

Shot Peening in the Automotive Industry

in Vol. 18 - November Issue - Year 2017
How About Shot Peening Modeling?
Mario Guagliano

Mario Guagliano

I recently attended the 13th International Conference on Shot Peening (ICSP13), a traditional event where most of the people dealing with shot peening meet and discuss related issues every three years.
This time, the conference was in Montreal, perfectly organized by the École Politechnique Montreal and was really successful with a total number of attending people and sponsors quite beyond expectations. The conference is traditionally the right place to have an up-to-date picture of shot peening and what is going on with it. That is to say, it is possible to listen to nice presentations showing the latest research and results in the field.
Many things could be highlighted and discussed after having participated in various sessions and discussions following them.
In particular, I had the impression that modeling shot peening is making great steps forward and is becoming a tool for the set-up of the process. Indeed, also on previous occasions of the conference, it was possible to find papers dealing with finite element models, reproducing the conditions to get a determined Almen intensity and surface coverage and, then, to calculate the resulting residual stress field. This is not new! What is new is that now many models come from the industry, not from academia: in other words, these complex models are now used not only for a better understanding of the process but as a tool for correctly designing the process and possibly optimizing it.
Nevertheless, there are two other related points I would like to underline. The first is that now the focus is not only the determination of the residual stress field, as was common in the past. The models now consider also the other effects of shot peening on the impacted surface; roughness and surface work hardening. Indeed, the models are now generally mature for residual stress assessment while, in my opinion, need a further step to get the same results in terms of surface finishing, but it is important that this issue is now clearly recognized and addressed. A model was also presented dealing with the geometrical error induced by shot peening when it is applied to gears; in particular, to the upper part of the gear tooth (the "addendum"): this is quite interesting and important for possible optimization of the treatment, which would be too expensive if done by an experimental trial and error procedure!
The second point is that this time the models presented came not only from the aeronautic industry as usual in the past, but also from other industrial sectors such as earth-moving machinery and the automotive industry.
To be sincere, most of them come from aeronautics, but this is understandable, since the requirements and the peculiarity of this sector always guide innovation, not only in shot peening. But other sectors are now moving in this direction and this means that the importance to improve the process is now well recognized also in more traditional fields and not merely to consider it as a sort of "fixed black box", to be used always with the same parameters because "..we have always done like this! Why change?"
An approach like this is able to lead to strong improvement and change as the way shot peeing is done to possibly open new applications and consequently, new markets for the process.
I am sure that this will keep on going in the next three years and many more presentations about modeling from different industrial sectors will be discussed; hopefully, coming also from the automotive industry!

Shot Peening in the Automotive Industry
by Mario Guagliano
Contributing Editor MFN and
Full Professor of Technical University of Milan
20156 Milan, Italy
E-mail: mario@mfn.li