稀土变质后低合金耐磨铸铁的热疲劳性能

Thermal Fatigue Property of RE Modified Low Alloy Wear Resisting Cast Iron

摘要: 分别对未变质和经稀土变质处理的低合金耐磨铸铁进行了热疲劳循环试验,研究了稀土变质处理对低合金耐磨铸铁热疲劳性能的影响.结果表明:该耐磨铸铁经稀土变质处理后,其共晶碳化物由未变质的网状分布变成断续网状和孤立块状分布,热疲劳裂纹扩展激活能由变质前的26.52 kJ·mol-1增大到变质后的30.15 kJ·mol-1,热疲劳裂纹扩展速度降低,变质处理提高了该耐磨铸铁的热疲劳性能.

Abstract: Thermal fatigue cycling tests for low alloy wear resisting cast iron with RE modification and without RE modification were carried out,and the effect of RE modification on the thermal fatigue property of the low alloy wear resisting cast iron was investigated. The results show that after RE modification,the eutectic carbide of the cast iron became broken netlike and separate blocks distribution from original netlike distribution. The thermal fatigue crack propagation activation energy increased from 26.52 kJ·mol-1 for the sample without RE modification to 30.15 kJ·mol-1 for the sample with RE modification,and the thermal fatigue crack propagation rate decreased after RE modification. As a result,RE modification can improve the thermal fatigue property of the cast iron.