玻璃模具用梯度石墨铸铁的组织与性能

Microstructure and Performance of Cast Iron With Gradient Graphite Structure for Glass Mold

国内外广泛采用梯度石墨结构铸铁作为瓶罐类玻璃模具材料,但使用寿命存在显著差距。对实际使用的梯度石墨铸铁模具进行了对比分析,结果表明:国内外模具材料石墨形态与分布相似,由内侧的D型石墨过渡到外侧的A型石墨时,材料抗压强度下降;石墨形态为D型时,抗压强度与基体显微硬度呈线性关系;进口玻璃模具材料基体组织基本为铁素体,塑性较好,国产玻璃模具材料基体含约10%(体积分数)的片状珠光体,强度高,但是塑性较差;玻璃模具使用寿命与模拟热疲劳寿命趋势一致,均属于低周疲劳破坏,寿命主要决定于模具材料的塑性。

Cast iron with gradient graphite structure is widely used as glass mold material for producing bottles and cans. However, there is a significant difference in service life between domestic and imported glass molds. Both domestic and imported cast iron molds were investigated. The results show that the morphologies and distributions of graphite in different materials are similar. The compressive strength declines as the morphology of graphite changes from D-type in inner side to A-type in periphery. There is a liner relationship between the compressive strength and the micro-hardness of matrix when the graphite morphology is D-type. The matrix of imported mate- rial is essentially ferrite, thus possessing better plasticity. But the one in domestic material contains approximately flake pearlite of 10% （volume fraction）, thus possessing better strength and worse plasticity. The service lifes of glass molds are consistent with thermal fatigue lifes. Both of them are low cycle fatigue fracture. The mold life de- pends on the plasticity of material.