Residual stress measurements in high strength steel after shearing operations
|Coordinator||Swerim AB - Swerim AB, Kista|
|Funding from Vinnova||SEK 500 000|
|Project duration||November 2018 - November 2019|
|Venture||Research infrastructure - utilisation and collaboration|
|Call||Research infrastructure - utilisation and collaboration: Industrial pilot projects for neutron and photon experiments at large scale research infrastructures|
Purpose and goal
The risk for Hydrogen embrittlement is hindering the use of extra high strength steels in e.g. automotive applications. This risk increases dramatically after shearing or punching since large residual stresses develop. These stresses are difficult to analyze with conventional x-rays due to its limited penetration in steel. The purpose of this project is to use synchrotron light due to much higher penetration. The goals are to: -Illustrate the potential for stress analysis in steel using synchrotron light. -Study macro- and micro stresses on sheared edges of high strength steels.
Expected results and effects
The outcome of this project will be a deeper understanding of the potential of residual stress analysis using synchrotron radiation for industrially relevant applied research of steel. If successful, this demonstrator will be followed by new applications for beam time by the project participants, since the results will be essential for the development of hydrogen embrittlement resistant high strength steels and for application instructions regarding punching, slitting and shearing of these. The results will be published in a scientific journal.
Planned approach and implementation
One steel producer, SSAB EMEA AB, and one research institute, Swerim AB, are participating in the project. Assistance with measurements and analysis will be given by DESY Photon Science at Petra III. Mapping of macro (peak shift) and micro (peak breath) stresses will be performed from the deformed edge and into the bulk of the steel sheet. The measurements will be performed on sheet steels with different strength levels and on edges produced by different methods: e.g. sheared, milled or laser cut. The intention is to measure with as high spatial resolution as possible.