高铬铸铁耐磨材料在泥沙磨损条件下耐磨性影响因素分析

Wearability of High Chromium Cast Iron at Sand Slurry Wear Condition

分析了碳化物形态与分布、基体组织和稀土变质处理对高铬铸铁耐磨材料在泥沙磨损条件下的耐磨性影响。结果表明 :碳化物的形态和分布对高铬铸铁的耐磨性有直接影响 ,块状或短杆状且分布均匀的碳化物对提高材料的耐磨性有利 ,网状或长针状碳化物对耐磨性不利 ;在泥沙磨损试验条件下 ,提高高铬铸铁中基体组织的显微硬度和基体组织与碳化物的结合强度有利于提高高铬铸铁材料的耐磨性 ;稀土元素的加入 ,使高铬铸铁的晶粒细化 ,碳化物颗粒变得细小 ,分布更为均匀 ,有利于提高高铬铸铁在泥沙磨损条件下的耐磨性。

Tests of several high chromium cast iron samples were made by self regulati ng sand slurry wear test machine. Wearability of the samples was measured and th e microstructures were observed by SEM. The influence of form and distribution o f carbide, base structure and rare earth treatment on wear resistance of high c hromium cast irons was analysed at sand slurry condition. The resluts show that the form and distribution of carbide have great influence on wearability of high chromium cast iron. Bolck or short shaft shape and uniformly distributed carbid es contribute to the wearability. Net or long needle shape carbides are not bene ficial to the wear resistance. The wearability can be improved by increasing mic rohardness of base structure and bond strength of base structure and carbides. T he addition of rare earth elements can also improve the wear resistance of the h igh chromium cast irons at sand slurry wear condition.