2205双相不锈钢连铸过程中夹杂物的形成机制

为了研究2205双相不锈钢连铸过程中夹杂物的特征及形成机制,从2205双相不锈钢连铸中间包和板坯上分别取试样,利用扫描电镜分析夹杂物的类型及形貌特征,并结合热力学计算探讨夹杂物的演变规律及其形成原因。结果表明,2205双相不锈钢中间包中存在大于10μm的夹杂物,中间包中夹杂物类型主要为CaO-Al_2O_3和CaO-Al_2O_3-MgO球形夹杂物,板坯中夹杂物尺寸都小于10μm,板坯中CaO-Al_2O_3和CaO-Al_2O_3-MgO球形夹杂物外面包裹了一层TiN。错配度和热力学计算表明凝固过程中CaO-Al_2O_3和CaO-Al_2O_3-MgO球形夹杂物为TiN的析出提供了形核质点。

Formation mechanism of inclusions in 2205 duplex stainless steel during continuous casting

In order to research the characteristics and formation mechanism of inclusions in 2205 duplex stainless steel during continuous casting，the samples taken from tundish and slab of 2205 duplex stainless steel were investigated and identified through the scanning electron microscope to characterize the type and morphology of inclusions. The evolution and formation reason of inclusions were analyzed by thermodynamic calculation. The results show that the inclusions with size larger than 10μm exist in the tundish. The inclusions in tundish are mainly spherical CaO Al2O3 and CaO Al2O3 MgO ones, while in slab, the spherical CaO Al2O3 and CaO Al2O3 MgO inclusions, with size less than 10μm, are enwrapped by a TiN layer. The mismatch and thermodynamic calculation showed that the spherical CaO Al2O3 and CaO Al2O3 MgO inclusions can be used as the nucleation points of TiN.