Work

Experimental Investigation of Delayed Fracture Initiation in Advanced High-Strength Steel Under Accelerated Bending

Year: 2025

Type: article

Abstract: Predicting bending fractures in advanced high-strength steel (AHSS) is challenging due to complex microstructural behaviors and strain rate dependencies, particularly in industrial forming processes. Current models and standards primarily focus on quasi-static tension or slow bending speeds, leaving a gap in understanding the accelerated failure of AHSS without necking. In this study, direct bending experiments were conducted on dual-phase, complex-phase, and martensitic AHSS grades under varying bending speeds and radii. Since the bending crack is irrelevant to the load drop, surface crack evolution was measured using three-dimensional surface profile analysis. The results showed that accelerated bending significantly delayed crack initiation across all tested materials, with small-radius bending showing reduced strain localization due to strain rate hardening. Larger-radius bending benefited primarily from increased fracture strain.

Source: Materials

DOI: 10.3390/ma18143415

Authors: Kyucheol Jeong, Jaewook Lee, Jonghun Yoon

Institutions: Hanyang University, Pohang Iron and Steel (South Korea)

Language: English

Topic: Metal Forming Simulation Techniques

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,137

Funders: Ministry of Trade, Industry and Energy, Korea Institute for Advancement of Technology