# Improved Wire Quality of Twinning-Induced Plasticity Steel During Wire Drawing Through Temperature Gradient with Warm Die

## TL;DR

A new method improves the quality of TWIP steel wires by using a temperature gradient during drawing, enhancing their performance and uniformity.

## Contribution

A temperature gradient with a warm die improves TWIP steel wire drawability and microstructural homogeneity by controlling stacking fault energy.

## Key findings

- Using a warm die increases wire drawability by 33% compared to a cold die.
- Higher surface temperatures suppress twinning at the surface, leading to a uniform twinning rate.
- Controlling stacking fault energy through temperature improves formability in TWIP steels.

## Abstract

The drawability and microstructural homogeneity of twinning-induced plasticity (TWIP) steel were improved during the wire drawing process by utilizing a temperature gradient along the wire’s radial direction. The surface temperature of the wire increased by applying heat to the die during the drawing process, thereby creating a temperature gradient across the wire during wire drawing. The drawability of the wire subjected to the temperature gradient with warm die (WD) increased by approximately 33% compared to that of conventional wire drawing with cold die (CD). The higher temperature of about 300 °C at the surface region of the wire with the WD suppressed the twinning rate at the surface region owing to the increase in the stacking fault energy (SFE) from 34 to 55 mJ/m2, leading to a uniform twinning rate along the wire’s radial direction compared with the CD wire, finally resulting in the improvement of the homogeneity in the microstructure and mechanical properties of TWIP steel. As a result, the drawability of the TWIP steel improved. Therefore, the general conclusion was derived that controlling the SFE within the area of the workpiece by tailoring the temperature can improve the formability in TWIP steels during the plastic forming process.