适用于增压器壳体材料的高镍球墨铸铁的高温氧化性能

High-temperature Oxidation Resistance of High-nickel Ductile Iron Applied for Turbocharger Housing Material

针对增压器壳体材料使用温度的日益升高,采用增重法研究了高镍Hi-Ni球墨铸铁和普通球墨铸铁QT400-18在500~900℃的高温氧化行为,并结合X射线衍射和扫描电镜等分析手段,对氧化膜的形貌和相组成进行了评价。研究发现:在500~900℃下,Hi-Ni材料的高温抗氧化性能明显优于QT400-18材料的高温抗氧化性能,其主要氧化产物为Fe2O3和Fe3O4,膜层对基体的保护性较好。从耐氧化性的角度评价,Hi-Ni材料可满足涡轮增压壳体材料在900℃下的使用要求。而QT400-18材料在700℃以上氧化后的产物为Fe2O3,Fe3O4和FeO,膜层对基体的保护性较差。

Working temperature of turbocharger housing material increases steadily due to increasing technique demands.High-temperature oxidation resistance at 500-900℃of two kinds of ductile iron,high-nickel ductile iron and QT400-18,was studied by gaining in weight method.Morphology and phase analysis of oxidation resultants were investigated using XRD and SEM.The results indicated that,high-temperature oxidation resistance of high-nickel ductile iron was obviously better than that of QT400-18,and the main resultants of the former were Fe2O3 and Fe3O4,which were characterized by agood oxidation protection on the substrate.Based on evaluation of oxidation resistance of materials,high-nickel ductile iron could been applied as a turbocharger housing material worked at 900℃.But for QT400-18,the resultants were Fe2O3,Fe3O4 and FeO when oxidation temperature was over 700℃,and the oxidation films were characterized by apoor oxidation protection on the substrate.