Influence of External Heat on Texture of Short Circuit Melted Mark in Electrical Fire

摘要

In order to demonstrate the relationship between the microstructure of copper short circuited melted mark and the external heat condition in electrical fire and develop the quantitative analyses of the PSM(the primary short circuited melted mark) and SSM(the secondary short circuited melted mark), some work to study the PSM and SSM has been did. This paper based on the experiment simulated the primary short circuit and secondary short circuit at different numbers of burning timber, and with the help of the powder X-ray diffraction, scanning electron microscope and energy dispersive spectroscopy. It is found that it is different for the trend of the grain size with the heat treatment time between PSM and SSM, and the curves of the texture coefficient with the heat treatment temperature between PSM and SSM also shows the change of their respective obviously, meanwhile, to further study the chemical composition, there are mainly some elements, C, O, Cu, especially, in deposition layer, the oxygen ratio for the PSM is about 6% and the oxygen ratio for the SSM is about 3%, in the melted mark substrate, the oxygen atomic ratio have not changed very much basically, and it is at around 3% for both PSM and SSM. The external heat has a special influence on microstructure of PSM and SSM.