Residual stress measurements in high strength steel after shearing operations
| Reference number | |
| Coordinator | Swerim AB - Swerim AB, Kista |
| Funding from Vinnova | SEK 500 000 |
| Project duration | November 2018 - December 2019 |
| Status | Completed |
| 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 - 2018 |
| End-of-project report | 2018-04419_SSAB_Europe.pdf (pdf, 486 kB) |
Purpose and goal
High residual stresses at cut edges can cause cracking that limit the usage of high strength steels. The aim of the project has been to illustrate the benefit of residual stress measurements at cut edges by diffraction of synchrotron light. SSAB and Swerim have collaborated and significantly increased their knowledge in this area. The objective to measure macro and micro residual stress with higher resolution than is possible with conventional techniques has been fulfilled. The technology will be used in other project.
Expected results and effects
Detailed information about residual stress for different cutting methods has given valuable knowledge that SSAB can use to develop recommendations to customers about cutting of high strength steel. Methods for evaluation of micro and macro residual stress data for synchrotron light have been developed and will be used for future measurements. The successful results have generated several new project applications, and the value of this will be increased industrial use of LSI facilities.
Planned approach and implementation
Local macro and micro residual stresses have been studied with synchrotron light at Petra III, Hamburg on three high-strength cold-rolled steels after shearing, milling and laser cutting. The tensile strengths of the steels were 1200, 1400 and 1700 MPa and the sheet thickness 1-1.5 mm. The measurements were carried out in transmission on samples thinner than 2 mm taken perpendicular to the cut edge. The results were presented as two-dimensional maps of the residual stress level from the edge in to unaffected material for different stress directions. The resolution was 50 µm * 50 µm * 2 mm.