空蚀过程中灰口铸铁的剥蚀机制  

Dropping Mechanism of Grey Cast Iron Surface During Cavitation Erosion

作　　者：于志伟[1] 

机构地区：[1]大连海运学院

出　　处：《材料科学与工艺》1994年第4期71-74,共4页Materials Science and Technology

摘　　要：本采用空泡剥蚀与定位跟踪观察交替进行的方式研究了灰铸铁在自来水中空蚀过程的表面组织形貌变化。结果表明，空蚀期间，首先灰铸铁表面上的共晶片墨由表及里脱落，形成了表面凹沟并逐渐发展成为与其表层墨片空间形状相同的表面微裂纹。然后，这些微裂纹通过与其附近的蚀坑相联接或以自身短距离扩展的方式汇合，最后导致被裂纹包围的珠光体团整块剥落。此外，上述剥蚀过程还与石墨片的空间取向有关，墨片取向愈倾向平行于试样表面，其脱落、形成表面裂纹的时间愈短，这类石墨片所包围的珠光体团的剥落速度也愈快。The surface morphology of grey cast iron during cavitation erosion by water has been studied carefully with caviration erosion and observation in situ in turn. the results show that during the cavitation erosion period, some graphites drop off from the surface and form surface hollow and develop gradually the surface microcracks with the same shape as the flake giaphites, which propagate along the phase interface and pearlitic matrix on the effect of the mode Ⅰ,Ⅱ and Ⅲ impact load and lead to pearlitic colony dropping in “bulk”.The above process is related to the spacial orientation of the flake graphites. The more parallel to the specimen surface the flake graphites are,the more fast they drop, and so does those pealitic colonies surrounded by the flake graphite.

关 键 词：灰口铸铁 空蚀 剥蚀机制 

分 类 号：TG172.9[金属学及工艺—金属表面处理] TG143.2[金属学及工艺—金属学]