不同受热温度下一次短路熔珠显微特征分析

为考查冷却条件对导线一次短路熔珠显微组织的影响,实验模拟室内火灾的热环境,对一次短路熔珠进行加热处理,观察温度、加热时间对不同线径铜导线一次短路熔珠金相组织的影响.实验结果表明:温度及加热时问对铜导线一次短路熔珠的金相组织有较大影响,随着温度的升高,时间的增加,在达到某一温度后,细小的柱状晶逐渐长大,一次短路熔珠的细小晶粒变成粗大的柱状晶或胞状晶,有的甚至表现为等轴晶,与铜导线的火烧熔珠的金相组织特征有些相似.

The Metallographic Microcosmic characteristics Analysis on the Primary Short Circuited Melted Beads of Copper Wire Heated in Different Temperature

In this paper, primary short circuited melted beads were made and heated in a simulating fire scene and the crystal structure of the primary short circuited melted bead was observed. The result shows the temperature and duration have great influences on the crystal structure of the primary short circuited melted bead. With the increasing of the temperature and prolonging of the heating time, exiguous cylindrical crystal grew up gradually and turned to bulky cylindrical crystal or afterbirth-- like crystal, even isometric crystal was found in the melted bead.