Effect of Sulfur Content on the Hot Ductility of Sulfur-Containing Steel
摘要
This study investigates the impact of sulfur content on the hot ductility behavior of sulfur-containing steel. The hot ductility of experimental steels with sulfur contents of 0.005, 0.026, and 0.053 pct was evaluated using the Gleeble-3500 thermal-mechanical simulator. The microstructural characteristics, including crystal properties and dislocation distribution, were analyzed through transmission electron microscopy, while crystal orientation was assessed using electron backscatter diffraction. The findings indicate that as sulfur content increases from 0.005 to 0.053 pct, the DRX rate decreases, resulting in a reduction of RAmin from 74.2 to 60.4 pct at 900 °C to 1000 °C. Simultaneously, the precipitation of MnS inclusions increased by 0.122 pct. Given that Mn is an austenite-stabilizing element, the Mn-depleted zone around the MnS inclusions is beneficial to the precipitation of ferrite. Thus, the precipitation temperature of ferrite by 20 °C and increased the precipitation quantity by 10 pct at 650 °C to 900 °C. The rise in proeutectoid ferrite precipitation resulted in a decrease in RAmin from 43.4 to 25.8 pct. The increased precipitation temperature and quantity of intragranular ferrite raised the initial temperature for RA recovery in the experimental steel, with the recovery quantity increasing from 8.9 to 13.9 pct.