半固态过共晶高铬铸铁的制备及组织定量分析

Preparation of Semisolid Hypereutectic High Chromium Cast Iron and Quantitative Analysis of Microstructure

为改善过共晶高铬铸铁组织中粗大初生碳化物的形貌 ,采用冷却体法制备了碳化物明显细化、圆整的半固态坯料。通过分别改变浇注温度、冷却体斜度获得六组不同半固态浆料温度的凝固组织 ,并借助Leica图像分析仪分别定量分析了初生碳化物的形状系数和等效直径变化特征。研究表明 :采用本方法可明显改善碳化物的形象 。

In order to improve the morphologies of bulky initial carbides in hypereutectic high Cr cast iron, the ingot fine and round carbides within microstructure of the ingots were prepared by cooling-body method. The six solidified structures with different semisolid slurry temperature were obtained through the changing of pouring temperature and cooling-body gradient respectively, and the changing characteristics of the shape factor and equivalent diameter of initial carbides were quantitatively Analyzed via Leica image analyzer. The result indicated that the morphology of carbide is improved obviously by the cooling-body method, and the semisolid structure is affected greatly through the changing of pouring temperature and cooling-body gradient.