钛含量对中铬铸铁组织和性能的影响

Influences of Ti Content on Microstructure and Property of Medium-chromium Cast Iron

设计并制备了5种不同钛含量的中铬铸铁,借助OM、XRD、SEM、洛氏硬度计和冲击试验机、磨损实验机等研究了钛含量对材料的组织和性能的影响。结果表明,随钛元素含量增加,M7C3型碳化物的数量减少,而TiC数量增多,平均直径增大。钛含量超过2.0%(质量分数),TiC颗粒出现团聚。材料的硬度随钛含量变化很小,保持在55HRC左右,冲击韧度增加至5.6J/cm2。以Cr26型高铬铸铁做参照,干摩擦条件下的相对耐磨性最大达到1.63,磨损表面形成的犁沟深度随钛含量增加而变浅。

Medium-chromium cast irons with different Ti content were designed and casted. The microstruc tures and properties were studied with OM, XRD, SEM, rockwell hardness tester, impact testing machine and abra sion tester. The results showed that with the Ti content increasing, the fraction of M7C3 carbides decreased, howcver, TiC particles and the particles size increased. As Ti content beyonding 2.0 wt%, TiC particles agglomerate. The hardness changed little with Ti content and keep around 55HRC, while impact toughness increased to 5.6 J/cm^2. Comparing to high chromium cast iron of Cr26 type, the relative wear resistance in the dry sliding condition reached 1.63, and the furrow depth on the worn surface became lower with Ti content increased.