微合金钢连铸坯热送热装析出物的研究

Study on precipitation of micro-alloyed steel slab in process of hot-charging

利用Gleeble-3500热力模拟试验机模拟了热送热装和冷装工艺下微合金钢连铸坯动态析出物状况,试验结果表明:铸坯压力加工试验初始温度越高、析出物的尺寸越大;冷却速率越小,析出物的数量越多。钛的加入可以细化奥氏体晶粒,由于TiN的形成温度较高、Nb(CN)形成温度较低,TiN可以作为新的析出相的核心,有效的抑制了铌多而细小的弥散析出。

The dynamic precipitation of micro-alloyed steel slab was investigated through simulating the process of hot-charging and cold-charging performed on Gleeble-3500 thermal-mechanical simulator in laboratory. The experimental results show that precipi- tation size increases with the rise of experimental initial temperature, and the cooling rate is the lower, the amount of precipitation is the larger. The austenitic grain was re- fined by adding titanium, TiN acting as the nucleation of the newly precipitating phases was prevented Nb from being precipitated dispersedly because of the higher formation temperature of TiN and the lower formation temperature of Nb（CN）.