灰口铸铁空泡腐蚀过程的SEM跟踪观察

采用空泡腐蚀与定位跟踪观察交替进行的方式,研究了灰口铸铁在自来水中空泡腐蚀过程的表面形貌演变。结果表明:灰铸铁空泡腐蚀系由两个相继发生而又彼此联系的过程组成:(1)片状石墨由表及里脱落形成表面缝隙;(2)表面缝隙的扩展与交汇导致珠光体团块状剥落。还讨论了石墨片的空间取向对珠光体团剥落的影响。

IN STTU SEM OBSERVATION ON THE SURFACE OF GREY CAST IRON DURING CAVITATION CORROSION

The surface morphology progression of grey cast iron due to cavitation erosion induced by tap water has been studied carefully by cavitation corrosion test and SEM observation in turn.The results show that cavitation corrosion of grey cast iron is composed of two o processes which occur in succession and are related to each other:(1)flake graphites spall off forming hollows:(2)development of the hollows leads to the spallation of pearlite colony. The influence of the orientations of the flake graphites on the spallation of pearlite colony is also discussed.