铸造铝硅合金熔炼过程中Ca含量的变化规律
发布时间：2019-04-29 12:42
【摘要】：以A356回炉料为对象,研究了熔炼温度和保温时间对Ca含量的变化规律。结果表明:Ca含量随着保温时间延长以二次曲线规律逐渐下降,低温时下降速率线性增大,高温时下降速率线性减小。当熔炼温度升高,Ca含量下降速率加快,在760℃熔炼时只经过3h就能达到最低含量6×10~(-6)。通过热力学和动力学分析可知,[Ca]主要通过前期被氧化和中后期扩散至熔体表层还原氧化铝的方式降低。温度越高,[Ca]与氧化铝开始反应的时间越短。在660~720℃熔炼初期,Ca氧化速率随温度变化满足K=578 749exp[-176 500/(RT)]规律。
[Abstract]:The effect of melting temperature and holding time on the content of Ca was studied by taking A356 recharging material as an object. The results showed that the content of Ca decreased gradually with the prolongation of the holding time, the decrease rate increased linearly at low temperature, and decreased linearly at high temperature. When the melting temperature is increased, the decrease rate of Ca content is accelerated, and the lowest content of 6 脳 10 ~ (- 6) can be achieved only after 3 hours of melting at 760 鈩，
本文编号：2468252
[Abstract]:The effect of melting temperature and holding time on the content of Ca was studied by taking A356 recharging material as an object. The results showed that the content of Ca decreased gradually with the prolongation of the holding time, the decrease rate increased linearly at low temperature, and decreased linearly at high temperature. When the melting temperature is increased, the decrease rate of Ca content is accelerated, and the lowest content of 6 脳 10 ~ (- 6) can be achieved only after 3 hours of melting at 760 鈩，
本文编号：2468252
本文链接：https://www.wllwen.com/kejilunwen/jiagonggongyi/2468252.html
