ESP工艺下低碳钢奥氏体演变行为

通过楔形铸坯直接轧制和带有中间坯补热工序的大道次变形量热轧实验，研究了铸坯直接轧制、大道次变形量以及中间坯补热工序对奥氏体组织演变的影响，并与常规热轧工艺进行了对比.结果表明:随铸坯压下率增加，变形后奥氏体晶粒尺寸逐渐细化.与铸坯再加热轧制工艺相比，当压下率为48%，53.6%和66.7%时，铸坯直接轧制工艺的奥氏体晶粒较为粗大，压下率为72.3%时，其变形组织更为细小均匀.与常规工艺相比，粗轧阶段大道次变形量促进奥氏体再结晶；中间坯补热工序提高了奥氏体晶粒尺寸均匀化程度.

Austenite Evolution in Low-Carbon Steel Under Endless Strip Production Process

The effects of the direct rolling of cast billet， large pass deformation and intermediate billet heating on microstructure evolution of austenite in low-carbon steel were studied in direct rolling experiment of wedge-shaped cast billet and hot rolling experiment of large pass deformation with intermediate billet heating， and were also compared with austenite evolution in the conventional hot rolling process. The results show that grain size of the austenite decreases gradually with increasing the reduction rate. Compared with the reheating rolling process， the austenite grains after the direct rolling process are coarser in the reduction rate of 48%， 53.6% and 66.7%， while the deformed microstructure becomes finer and more homogeneous when the reduction rate is 72.3%. In comparison with the conventional hot rolling process， the large pass deformation promotes austenite recrystallization in the rough rolling stage， while the intermediate billet heating process improves the uniformity of grain size in the austenite.