重型车长寿命制动鼓的开发

Development of Long Working Life Brake Drum Used for Heavy Truck

对重型车制动鼓开裂问题进行了分析,研究表明:(1)重型车制动鼓产生开裂的原因是制动鼓工作温度高,摩擦部位截面存在大的热应力,以及制动鼓材料导热性不足;(2)铸件材料牌号达到HT250并且铸件本体强度190～230 N/mm2,制动鼓强度已足够,使用中不会因为制动鼓强度不足产生开裂问题。试验表明:HT250制动鼓的w(C)量从3.30%提高到3.40%～3.70%,适当加入合金元素,大大改善了制动鼓的抗热裂能力,提高了制动效能,解决了重型车制动鼓使用过程出现的开裂、摩擦面硬斑等失效问题,提高了汽车的安全性。

The cracking problem of the heavy truck brake drum was analyzed.Investigation indicated：（1）The reason causing heavy truck brake cracking was that its working temperature was too high that led to high thermal stress in the section of friction area,as well as the low thermal conductivity of the brake drum material;（2）as long as the strength of the casting material reached HT250 grade and the strength of the casting body reached 190-230 MPa,the strength of the brake drum would be enough to avoid cracking problem.Test showed that by increasing the C content from 3.30% to 3.4%～3.7% and adding proper amount of alloying elements,the anti-thermal cracking ability of the brake drum was obviously improved,the braking effect was increased,and thereby the braking drum cracking problem and hard spots problem of the friction surface has been solved and so that the truck safety of the truck was also improved.