The influence of intrinsic formability parameters on the sheared-edge ductility of 120K-class AHSS

Abstract

Abstract With enduring versatility, advanced high-strength steels (AHSS) play an increasingly important role in securing automotive safety, performance and sustainability targets in future automotive architectures. However, local formability (resistance to cracking) is of specific relevance to AHSS, and various intrinsic fracture-related concepts have emerged with the goal of understanding and improving the local formability of AHSS (sheared-edge ductility, bendability). This analysis is focused on the relationships between intrinsic formability parameters and other laboratory-scale performance indicators—i.e. the ISO 16630 hole expansion ratio (HER). Included is the AHSS material with minimum tensile strength designation above 1.2GPa: 120K-class 3rd generation AHSS. Additionally, the impact of material property uniformity on HER, and local toughness concept based on the true fracture strain is explored.