制动盘用灰铸铁热疲劳性能的研究

Study on Thermal Fatigue Property of Gray Cast Iron Brake Disc

灰铸铁具有优良的导热性、良好的耐摩性,是制动盘的主要材质。对3种碳当量较高的灰铸铁组织及性能进行了测定和分析,采用板状带V型缺口试样,通过循环加热、冷却的方法研究热疲劳性能。结果表明:碳当量比较低、石墨数量少,即使强度和硬度比较高,抗热疲劳性能也较差;当基体以珠光体为主时,碳当量高且含有一定量D型石墨的灰铁抗热疲劳性能好。

Gray cast iron was the main materials of brake discs for its excellent thermal conductivity and wear resistance.Microstructure and properties of three kinds of gray cast iron with high carbon equivalent were measured and analyzed.Under the condition of cyclic heating and cooling,and plate type specimens with'V'notched was used,their thermal fatigue resistance was studied.The results show that if relatively low carbon equivalent,thus less graphite,even with high strength and hardness,thermal fatigue resistance is also poor.When the matrix is mainly pearlite,gray cast iron with high carbon equivalent and a certain amount of D-type graphite has good thermal fatigue property.