电流强度对铜导线过电流迸溅熔珠晶粒特征的影响分析

Influence of Current Intensity on the Crystal Characteristics of Over Current Melting Bead Markers Splashed from Copper Wire

在不同电流强度条件下制备过电流铜导线迸溅熔珠,使用金相法对迸溅熔珠进行归类分析,借助Image-Pro Plus从大小和形状两个方面定量分析电流强度对晶粒特征的影响。实验结果表明:过电流迸溅熔珠的金相组织共有4种类型,其中大部分熔珠的金相组织为细小柱状晶,不同电流强度对4类金相组织的出现频率没有明显影响,且电流强度为额定电流的5.5倍时,细小柱状晶的面积和圆度出现极小值。实验所得结论可为实际火灾调查中判别线路故障类型提供参考。

The melted bead marks ejected from over-current copper wire were prepared under different current intensity conditions. The beads were classified and analyzed by metallographic method and the current intensity influence on crystal particle features was quantitatively analyzed from size and shape via means of Image-Pro Plus. The experimental results showed most of the four metallographic structure types of the beads were fine columnar crystals,different current intensity had no significant effect on the occurrence frequency of microstructure types,and the minimum crystal area and roundness appeared with the 5. 5 times rated current intensity. The conclusion could technically support identifying the wire fault type in actual fire investigation.