半固态高铬铸铁初生相的形貌及其定量分析

Morphology of Primary Phase in Semisolid High Chromium Cast Iron and Its Quantitative Analysis

为改善高铬铸铁组织中初生枝晶奥氏体的形貌,采用倾斜冷却体法制备了奥氏体明显细化、圆整的半固态高铬铸铁坯料。在冷却体斜度及熔体在其表面流经长度不变的条件下,通过改变浇注温度获得三组不同半固态成型温度所对应的凝固组织,并借助Leica图像分析仪分别定量分析了初生奥氏体的形状系数和等效直径的变化特征。研究工作表明采用本方法可明显改善奥氏体的形貌,浇注温度的变化对半固态组织有较大影响。

In order to improve the morphology of primary dendritic austenitic in high Cr cast iron the semisolid high Cr cast iron ingots with fine and round austenite were prepared by cooling the metal stream through an inclined cooling channel. Under fixed inclination angle and cooling length of the cooling channel three groups of solidified structures were obtained by changing pouring temperature. The shape factors and equivalent diameters of primary austenitic were quantitatively analyzed using a Leica image analyzer. The result indicated that the morphology of primary austenitic is improved significantly by the cooling method; semisolid structure is affected greatly by changing pouring temperature.