Work

Global and High-Resolution Damage Quantification in Dual-Phase Steel Bending Samples with Varying Stress States

Year: 2019

Type: article

Abstract: In a variety of modern, multi-phase steels, damage evolves during plastic deformation in the form of the nucleation, growth and coalescence of voids in the microstructure. These microscopic sites play a vital role in the evolution of the materials’ mechanical properties, and therefore the later performance of bent products, even without having yet led to macroscopic cracking. However, the characterization and quantification of these diminutive sites is complex and time-consuming, especially when areas large enough to be statistically relevant for a complete bent product are considered. Here, we propose two possible solutions to this problem: an advanced, SEM-based method for high-resolution, large-area imaging, and an integral approach for calculating the overall void volume fraction by means of density measurement. These are applied for two bending processes, conventional air bending and radial stress superposed bending (RSS bending), to investigate and compare the strain- and stress-state dependent void evolution. RSS bending reduces the stress triaxiality during forming, which is found to diminish the overall formation of damage sites and their growth by the complimentary characterization approaches of high-resolution SEM and global density measurements.

Source: Metals

DOI: 10.3390/met9030319

Authors: Rickmer Meya, Carl F. Kusche, Christian Löbbe, Talal Al-Samman, Sandra Korte-Kerzel, A. Erman Tekkaya

Institutions: TU Dortmund University, RWTH Aachen University

Language: English

Topic: Metal Forming Simulation Techniques

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,520

Funder: Deutsche Forschungsgemeinschaft