论文部分内容阅读
本研究的主要目的是优化15%Cr-2%Mo过共晶白口铸铁的冲击韧性和耐磨性。研究了动态凝固、铌元素添加和二者共同作用及热处理的影响。采用图像分析仪,扫描电子显微镜(SEM),能量色散光谱仪(EDS)和X射线衍射仪等仪器,对冲击韧性和耐磨损性能进行了测试,还对断口和磨损表面进行了研究。结果表明,对于过共晶(白口)铸铁,凝固过程中的微观组织控制是取得冲击韧性和耐磨性之间的最佳组合的最重要手段。在提高冲击韧性和耐磨性上,添加铌和动态凝固综合作用比每个单一因素更有效。在铸态条件下,动态凝固的冲击韧性和耐磨性比静态凝固分别提高71.4%和10%。加入2%铌后,分别进一步提高到114.3%和28.8%。较低的回火温度260℃比亚临界回火温度500℃显示出更好的耐冲击性和耐磨性。
The main objective of this study was to optimize the impact toughness and wear resistance of 15% Cr-2% Mo hypereutectic white cast iron. The effects of dynamic solidification, addition of niobium and their interaction and heat treatment were studied. The impact toughness and wear resistance were tested by using image analyzer, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffractometer. Fracture and wear surface were also studied. The results show that for hypereutectic (white cast iron) microstructure control during solidification is the most important means of achieving the best combination of impact toughness and wear resistance. In terms of improving impact toughness and wear resistance, adding niobium and dynamic coagulation is more effective than each single factor. Under the as-cast condition, the dynamic toughness and impact resistance of static solidification increased by 71.4% and 10% respectively. After adding 2% niobium, it further increases to 114.3% and 28.8% respectively. Lower tempering temperature of 260 ℃ than the subcritical tempering temperature of 500 ℃ showed better impact resistance and wear resistance.