Effects of Sulfur and Manganese on the Hot Workability of Austenitic Stainless Steels

摘要

Effects of sulfur and manganese content on the hot workability of 316L, 309S and 310S stainless steels have been investigated by the hot tensile and the hot compressive tests. The hot ductility of 316L, 309S and 310S steels was decreased with increasing sulfur content and/or reheating temperature. A part of precipitated sulfides formed under the solidification process was redissolved during reheating. The solubility of sulfur is increased with increasing reheating temperatures and with decreasing manganese content. Under the hot rolling conditions the redissolved sulfur segregated at grain boundaries and/or reprecipitated as sulfides. The initiation of reprecipitation occurred at relatively lower level of sulfur as the manganese content is higher. This segregation or reprecipitation behavior plays a major role on the loss in ductility. The ductility was also strongly governed by the morphology or composition changes of reprecipitated sulfides. It was suggested that a lowering in reheating temperature would minimize sulfur effect during hot rolling for austenitic stainless steels.