Research on tribological behavior and mechanism of laser surface texturing on tool surface in hot stamping of Al-Si-coated high-strength steel

The hot stamping of Al-Si-coated high-strength steel (HSS) sheets is an important manufacturing process that has gained significant attention in recent years. However, the friction and adhesive wear that occur during the process have become major bottlenecks, limiting the efficiency and effectiveness of the process. To address this problem, a comprehensive investigation was conducted to evaluate the tribological behavior of the contact interface between Al-Si-coated HSS sheets and tool steel during hot stamping. Specifically, micro-dimpled laser surface textures (LSTs) with varying densities were applied to the H13 tool steel surface, followed by an examination of their effectiveness in reducing friction and wear. The 3D morphology of the wear scratches was assessed using a laser confocal surface roughness system, while SEM and EDS techniques were utilized to analyze the mechanisms behind friction reduction and wear resistance. The results demonstrated that laser surface texturing (LST) effectively reduces the friction coefficient between Al-Si-coated HSS sheets and H13 tool steel under high-temperature and high-pressure conditions. Moreover, it was found that LSTs exhibiting densities of 30% retained their pitted morphology following friction experiments, indicating a remarkable capability in reducing adhesive wear and facilitating debris collection. The average coefficient of friction (COF) was observed to be significantly lower in textured specimens than in untextured specimens by approximately 64.62%, 52.3%, 51.9%, and 67.11% at pressures of 5 MPa, 10 MPa, 15 MPa, and 20 MPa, respectively. This study offers a novel concept and method that leverages the LST technology to mitigate the friction and wear of Al-Si-coated HSS sheets during the hot stamping process. The findings also shed light on the anti-wear effect and the mechanism of LST in such conditions. Overall, this study highlights the potential of LST as a promising method for enhancing the efficiency and effectiveness of the hot stamping process involving Al-Si-coated HSS sheets.