With the help of the powder X-ray diffraction,scanning electron microscope and energy dis-persive spectroscopy,the PSM and SSM were studied to develop the quantitative analyses and demonstrate the relationship between the phase transition of copper melted mark the external heat condition in electri-cal fire.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 shows the respective trend obviously.The chemical composition,included mainly carbon,oxy-gen and copper.The ratios of oxygen for the PSM is about 6%,and the ratio of oxygen for the SSM is a-bout 3%in deposition layer.The atomic ratio of oxygen has not changed very much basically in the mel-ted mark substrate,and it is at around 3% both PSM and SSM.The external heat has a different influ-ence on phase transition of PSM and SSM,and the microstructure could reveal clearly,therefore,it is possible to set up the quantitative analyses for short circuit melted mark.%为建立电气火灾物证鉴定关于一次短路熔痕和二次短路熔痕的量化分析，研究外热条件对短路熔痕的影响，借助X射线衍射仪和扫描电镜及能谱仪，分析短路熔痕的微观结构和成份信息。实验结果显示：在特定的热处理时间变化趋势下，一次短路熔痕晶粒大小的发展趋势与热处理时间趋势一致，二次短路熔痕晶粒大小的发展方向与热处理时间的变化趋势相反，而且，一次短路熔痕织构系数的平均值随外热温度的上升，先增大后减小，二次短路熔痕织构系数的平均值只在较小数值范围内波动。进一步分析短路熔痕不同区域的化学成份发现，一次短路熔痕和二次短路熔痕主要含有C、O和Cu三种元素，在熔痕的沉积层，一次短路熔痕的氧含量约为6％，二次短路熔痕的氧含量约为3％，但在熔痕基体区，一次短路熔痕和二次短路熔痕的氧含量基本无变化，均在3％左右，不随外热温度和热处理时间变化。从研究结果可知，在600℃内的电气火灾中，短路熔痕随外热温度和热处理时间变化的相关数据可以成为短路熔痕量化分析的基础。
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