From July 2017 to June 2020, the European collaborative project LEAFSLIM “Lightweight steel Leaf Springs with improved durability and reliability” is running focused on the development of a new generation of ultra-light leaf springs. The project is leaded by the special steelmaker SIDENOR I+D (E) and participated by the leaf spring maker Muelles y Ballestas Hispanoalemanas (E), the research center Karlsruher Institut Für Technologie (D), the university of Thessaloniki (GR) and STRESSTECH (D), a small company specialized in residual stress analysis.
The project budget sums up 1.519.811,20 € and is 60% granted by the Research Fund for Coal and Steel (RFCS). The weight reduction aim is achieved through:
- Development of novel steel grades for lightweight leaf spring applications
- Optimization of the Residual Stress profile through innovative stresspeening processes to achieve an enhanced profile of residual stresses, smoother surface roughness and relaxation resistance
- Improvement of fatigue performance of the final components through a decrease in crack propagation rate within the residual stress field
Besides truck suspensions, the novel steel grades and technologies can be applied for railway and industrial springs, hand tools, farm machinery and other harder and tougher uses. Novel stresspeening technologies may have even a wider field of applications, as they can be applied in many sectors (aeronautics, energy, military, precision machinery, etc.) and for many products (gears, drills, guides, welded structures, crankshafts, etc.).