Numerical and Experimental Investigation on Hot Stamping of TWB B-Pillar

Abstract

In order to achieve the targeted crashworthiness performance, the application of Tailor-Welded-Blank (TWB) on the crash-relevant components has become a trend in the automotive industry. This paper aims to investigate the mechanical property and structural performance of the hot stamped TWB B-pillars. After hot stamping, the strength grade for the hard zone is 1500 MPa while the soft zone’s strength grade is 590 MPa. The CAE model shows that the intrusion distance is decreased for the TWB design compared to the monolithic material B-pillar. The three point bending performance could be adjusted by changing the range of the soft zone. It is observed that the weld line has a low crack sensitivity during hot stamping. The transition zone between the hard zone and soft zone is less than 1mm. The ATOS scanning results show that no significant effect on the part’s size deviation for the TWB design compared to the monolithic material B-pillar.

Low-Carbon-Emission Hot Stamping: A Review from the Perspectives of Steel Grade, Heating Process, and Part Design

“…Conversely, the lower section of the B-pillar requires lower strength but high plasticity to effectively absorb the car's impact energy, thereby maximizing passenger safety [88]. Huang et al [89] investigated the mechanical property and structural performance of the hot-stamped TWB B-pillars. According to the CAE results, the TWB design can reduce the intrusion distance at the passenger's chest height.…”