热变形低铬白口铸铁颗粒状碳化物形成的探讨

STUDY ON THE FORMATION OF GRANULAR CARBIDES IN LOW CHROMIUM WHITE CAST IRON THROUGH HOT DEFORMATION

通过金相显微镜和扫描电镜的观察 ,探讨了热变形低铬白口铸铁中颗粒状碳化物的形成 ,分析认为 :尺寸较大的碳化物来源于铸态中棒状碳化物 ;尺寸较小的碳化物直接从基体中形核 ;尺寸介于两者之间的来自热变形诱发析出 ,且变形量越大则细小的颗粒状碳化物数量越多。

The granular carbides formed by hot deformation in low chromium white cast iron were studied through the observation with optical microscope and scanning electron microscopy.The experimental results showed that carbides of large size formed from bar like shape carbides,those of small size directly nucleated in the matrix,while the carbides with the sizes between the above mentioned formed from precipitation induced by hot deformation.The heavier the deformation was,the larger the number of microsized granular carbides was.