单股铜导线一次短路熔痕的多层金相分析

The Primary Short Circuited Melted Mark's Multiple Metallographic Study of Copper Wire

金相法是电气火灾原因技术鉴定中最常用的方法之一,能为电气火灾的原因认定提供重要依据,而多层金相相比于单层金相分析更加精确,分析结果更加真实。采用多层金相法对一次短路熔痕进行试验分析,结果表明:一次短路熔痕的金相组织熔化区呈细小的柱状晶或胞状晶,非熔化区呈铜导线原始的等轴晶,气孔小而少。对比观察单股铜导线一次短路熔痕的金相组织,不同层的金相截面中晶粒形状、气孔分布都存在差异;同一温度不同截面金相组织中晶粒大小、形状有差异,气孔也有变化。试验为金相组织的研究与观察提供了新思路。

Metallographic method is one of the most commonly used method in the technical appraisal of an electrical fire cause and it can provide an important basis for the identification of fire causes. The experiment shows that in the melted zone, the sample appears in afterbirth- like crystal and cylindrical crystal while in the unmelted zone it appears in the original isometric crystal. The pores are both tiny and small. There are both huge differences in pore distribution and crystal shape in one metallographic section from various temperature, and in different metallographic section, the size, shape of the pores and crystals are very uneven. It proves a new method for the research and observation of metallographic analysis.