针对某些承受热循环工况的铸件，采用实验室手段，研究了不同石墨形态铸铁──灰铁、蠕铁、球铁在＞５０～４０℃循环温度下的热疲劳性能。结果表明，在本试验条件下，以球铁的热疲劳抗力最好，灰铁次之，蠕铁最差，研究结果可供实际生产中，选材时的参政。 For some castings subjected to thermal cycling conditions, the thermal fatigue properties of cast iron with different graphitic forms-gray iron, vermicular iron and ductile iron at> 50 ~ 40 ℃ were investigated by laboratory methods. The results show that under the test conditions, the thermal fatigue resistance of ductile iron is the best, followed by gray iron followed by that of vermicular iron. The results of this study are available for political participation in actual production and material selection.