半固态过共晶高铬铸铁的冲击及磨损性能研究

Impact and Wear Properties of Semisolid Hypereutectic High Chromium Cast Iron

通过倾斜冷却体法制备了组织中初生碳化物明显细化的半固态过共晶高铬铸铁,其冲击韧性值较常规过共晶高铬铸铁试样提高了大约1倍以上;以常规亚共晶高铬铸铁为标样进行三体磨料磨损试验,结果表明半固态过共晶高铬铸铁与常规过共晶高铬铸铁的相对耐磨性分别比亚共晶高铬铸铁提高了32%和49%.对半固态过共晶高铬铸铁试样的微观分析表明,组织中存在大量的缩松,这对于半固态高铬铸铁韧性、硬度及耐磨性的提高产生了不利的影响,减少或消除缩松对于进一步提高半固态过共晶高铬铸铁的性能具有重要意义.

A semisolid hypereutectic high chromium cast iron with finer initial carbide in the microstructure was obtained by slope cooling body method, and the impact toughness reached above twice that of conventional hypereutectic high chromium cast iron. Three-body abrasion tests for the two sorts of hypereutectic high chromium cast iron and the hypoeutectic high chromium cast iron in common use were conducted to compare their wear resistances. The results indicate that the wear resistances of both hypereutectic ones are improved by 32% and 49%, respectively, compared with that of the hypoeutectic one. The microstructural analysis of the semisolid hypereutectic cast iron shows that a great quantity of shrinkage porosities hinder the improvement of impact toughness, hardness and wear resistance of the specimens, and it is significant to develop the properties of the semisolid hypereutectic ones by reducing or eliminating the shrinkage porosities.