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Vol. 8
November Issue
Year 2007
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MFN Trainer Column


in Vol. 8 - November Issue - Year 2007
Just A Complementary Peening Solution?



Albert Schlatter

This column is a regular feature and is written by one of our MFN trainers or the Editorial Office. Readers are invited to send comments or questions to info@mfn.li. For more information about the trainers, see our website www.mfn.li/trainers.

Often someone attending a seminar on shot-peening, thinks that the discussion will mainly be about the application of the air blast techniques.
I don’t know the reason for this fact, but maybe most people have little knowledge of blast wheel techniques and their possibilities in connection with shot and stress peening applications.
It’s just normal and human that one has little confidence in something more or less unknown.
The following is exemplary for such experience and underlines what I mean: A customer asked us for a shot peening solution for air craft turbine blades and for corresponding test purposes sent us blades of different sizes.
After the first test series in our testing laboratory in Schaffhausen, we sent the blades back to the customer for examination. He was highly pleased with the results and we received further blades with new and higher requirements. According to the customer these results and those from a further series of tests were excellent.
Finally this customer communicated that for his new installation he had again decided in favour of the air blasting technique, on the grounds that it wasn’t so far common practice to process these parts using blast wheel technology.
Exactly here I saw my current and future commitment. Without disregarding air blasting technology, I will put emphasis on blast wheel techniques and their advantages which certainly deserve an adequate place in shot- and stress peening applications.
There is sufficient room for both techniques, so that - depending on requirement profile and customer needs – pros and cons of both possibilities can be compared in order to find the most appropriate solution. A “competitive edge” between the two technologies will lead to new possibilities in each application field.
The above example clearly shows that new solutions even nowadays are difficult to implement; for me, a well comprehensible fact. However in my opinion it is very important to strive for the optimal, individual solution based on technical and/or economic advantages which will offer benefit to the user.
Since 1937 we in Schaffhausen have been manufacturing shot blast machines that have been sold all over the world. Blasting equipment 50 years old and still in service is nothing unusual and original spare parts are still available, even though new types of blast wheels have been developed in the meantime.
For this reason, many different types of blast wheels are available from our Group today. Such equipment is either applied in foundries for cleaning castings and forgings or in rolling mills for the descaling of stainless steel sheets.
As for shot- and stress peening applications special blast wheel requirements are requested – and it’s very important to know that each blast wheel type has its own characteristics – therefore we only use a few blast wheel types which, however, ideally meet requirements for these processing methods.

In conclusion I would underline that blast wheel technology must be competitive with air blasting technology as only through competition can both technologies develop.
Best Regards

Albert Schlatter
albert@mfn.li

 




Author: Albert Schlatter