# Study on Formability and Microstructure Evolution of Usibor®2000 Sheet Under Different Forming Temperatures in Deep Drawing Process

## TL;DR

This study examines how forming temperature affects the formability and microstructure of Usibor®2000 steel used in automotive lightweighting.

## Contribution

The paper provides new insights into the temperature-dependent formability and microstructure evolution of Usibor®2000 during deep drawing.

## Key findings

- Increasing temperature improves the forming limit and quality of Usibor®2000 sheets.
- Microstructure evolution under warm and hot forming conditions was characterized and analyzed.
- Phase composition analysis at 860 °C offers guidance for automotive lightweight applications.

## Abstract

Due to the need for weight reduction in the automobile structure, effective and accurate forming is demanded to take advantage of ultrahigh-strength steels. Research on the deep-drawing formability of Usibor®2000 has an important impact on the application of lightweight automotive bodies. The microstructure and formability of Usibor®2000 sheets at different temperatures were investigated by the Swift test. The positive effects of increasing the temperature on improving the forming limit and forming quality of Usibor®2000 were demonstrated by LDR results, thickness, and hardness measurement. The microstructure evolution of Usibor®2000 steel plates under warm forming and hot forming conditions was discussed in terms of microstructure characterization and precipitate morphology. The phase composition of the sample deformed at 860 °C is analyzed by two-step etching metallographic analysis and numerical simulation, which provides a reference for the application of Usibor®2000 ultrahigh-strength steel in automotive lightweight.