|About this Abstract
||NUMISHEET 2022: The 12th International Conference on Numerical Simulation of 3D Sheet Metal Forming Processes
||Characterization of the Formability of Al-Si Coated PHS1800 During Hot Stamping
||Ruijian He, Ryan George, Sante DiCecco, Pedram Samadian, Constantin Chiriac, Stephen George Luckey, Jimi Tjong, Cangji Shi, Jason Boettger, Cliff Butcher, Michael Worswick
|On-Site Speaker (Planned)
The formability of an 1800 MPa Al-Si coated hot stamped steel, designated PHS1800, was characterized using Nakazima, Marciniak, and hybrid Nakazima-Marciniak formability tests. Samples with widths from 13 to 229 mm were austenitized for five minutes in a chamber furnace at a nominal temperature of 930 °C. An automated system then transferred the sample to a hydraulic press with temperature-controlled tooling to perform the forming stroke at speeds up to 60 mm/s. Digital image correlation (DIC) techniques with in situ high speed stereo cameras were used to measure the local major and minor strains at the fracture location. The forming limit strains were then identified using both time-dependent and surface curvature-based necking detection methods for Nakazima tests, and using the ISO method for Marciniak and hybrid tests. Due to friction between the sample and the punch as well as rapid quenching at the apex of the punch, necking occurred within the higher temperature unsupported region between the punch and die for Nakazima tests. Numerical simulations of the Nakazima tests using LS-DYNA were developed to provide insight into the forming process and were modified to evaluate the alternative formability tests. The simulations and experimental results of the Marciniak and hybrid tests demonstrated that the carrier blank can be used to quench the region of the sample between the punch and die, thereby shifting necking toward the apex of the punch under a near monotonic strain path.
||Definite: At-meeting proceedings