Wear in Hot Stamping by Partition Heating

Abstract

Hot stamping by partition heating of Al–Si coated boron steel sheets is currently utilized to produce parts of the car body-in-white with tailored microstructural and mechanical characteristics. This paper investigates the evolution of the Al–Si coating and its tribological and wear performances in the case of direct heating at the process temperatures of 700 °C, 800 °C, and 900 °C, skipping the preliminary austenitization as it may happen in the case of tailored tempered parts production. A specifically designed pin-on-disk configuration was used to reproduce at a laboratory scale the process thermo-mechanical cycle. The results show the morphological and chemical variation of the Al–Si coating with heating temperature, as well as that the friction coefficient, decreases with increased temperature. Furthermore, the results proved that the adhesive wear is the main mechanism at the lower temperature, while abrasive wear plays the major role at the higher temperature.

Localized Laser Dispersing of Titanium-Based Particles for Improving the Tribological Performance of Hot Stamping Tools

“…However, studies from Venema et al [8] and Ghiotti et al [9] revealed, that both coating systems cannot withstand the alternating thermo-mechanical load conditions during the combined forming and quenching step. Consequently, excessive tool wear appears within short production periods, which negatively impacts the workpiece quality and the tool lifetime [10]. Moreover, the application of conventional lubricant systems is not possible during hot stamping, since blank temperatures above 800 • C occur.…”

Characterization of Thermomechanical Boundary Conditions of a Martensitic Steel for a FAST Forming Process

“…The friction coefficient under hot/warm stamping conditions is critical to describing the contact conditions at the tool-workpiece interface [8], as this affects the drawability of the material and the springback of the formed component [9]. It has been found that the friction coefficient decreased with increasing temperature, which is typically evaluated by either pin-on-disc/strip or drawing tests [10][11][12].…”