载重125t矿用车球墨铸铁大轮毂铸造工艺研究

Research on Casting Technology of Ductile Iron Large Wheel Hub for 125 Tons Mining Trucks

所述矿用车载重量125t,其轮毂尺寸较大、壁厚较厚,法兰直径是一般重卡的2倍,重82kg。在实际设计开发中出现本体屈服强度偏低、热节位置出现缩松缩孔缺陷、厚大部位产生金相石墨漂浮等问题。结合轮毂特点,通过增加Cu元素提高屈服强度,下调碳当量和降低浇注温度根除石墨漂浮,采用自制易隔片缩短补缩距离,降低和消除轮毂内部缩松缺陷倾向,对工艺进行了优化。结果表明,工艺优化后最终实现了轮毂的批量生产。该轮毂与普通商用车轮毂铸造工艺差别较大,需要在材质、工艺参数方面进行优化调整;提高冒口的补缩效率是改善轮毂内部质量关键;合理的补缩工艺不仅能够提高产品质量,还能提高工艺出品率、降低生产成本。

The load weight of the mining truck is 125 tons,its wheel hub size is larger,the wall thickness of wheel hub is thicker,the flange diameter is 2 times of the general heavy truck,the weight is 82 kg.In the actual design and development,there are some problems such as low yield strength of the wheel hub,shrinkage porosity and cavity defects in the hot spot,and floating of metallographic graphite in the thick part.Combined with the characteristics of the wheel hub,the process was optimized by increasing the yield strength by adding Cu element,reducing the carbon equivalent and the pouring temperature to eliminate the graphite floating,and reducing the feeding distance by using self-made easy inserts to reduce and eliminate the defect tendency of shrinkage cavity inside the wheel hub.The results show that the batch production of wheel hub is finally realized after the process optimization.The casting process of the wheel hub differs greatly from that of ordinary commercial vehicles,so the material and process parameters need to be optimized and adjusted.Improving the feeding efficiency of riser is the key to improve the internal quality of the wheel.Reasonable feeding process can not only improve the product quality,but also improve the production rate and reduce the production cost.