【摘要】 本文通过控制铸铁生产中的合金元素量、浇注温度、孕育剂量,得到在模具壁厚方向形成三级梯度石墨灰铸铁。利用SEM观察金相试样评价石墨形态、尺寸、分布;测试试样各梯度石墨区域的布氏硬度值评价铸铁的力学性能;观察热疲劳试样的疲劳裂纹的扩展评价试样的热力学性能。试验结果发现合金元素量V:0.11%~0.15%、Ti:0.15%~0.21%、浇注温度1360~1320℃、孕育剂量在0.35%~0.50%,模具在内腔区形成细小D型石墨,模具腔壁石墨逐渐长大B型,最后形成A型石墨的三级梯度石墨结构;梯度石墨结构兼顾内腔区模腔表面质量良好、径向高效散热能力和优异的耐热疲劳性能。更多还原

【Abstract】 By controlling the pouring temperature,alloying elements & the inoculant,a triple grades of graphite gradient cast iron in radius orientation of the glass mould are made.The morphology of the metallographic samples was studied by scanning electron microscopy;By testing of brinell hardness on the different region of samples,different hardness value are obtained;Test results showed that the alloy contains 0.11 ~ 0.15% V,0.15% ~ 0.21% Ti and 0.35% ~ 0.50% inoculant,The glass mold consists of three layers,where the fine D-type graphite was main composition of inner layer and A-type graphite covered the outer layer of the mold.The dies made from a structure gradient offers high surface smoothness of the mold,high thermal conductivity and thermal fatigue resistance along the die wall.更多还原