电气火灾中的电弧熔痕特征与外热关系
发布时间：2019-04-26 06:17
【摘要】：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。
[Abstract]:In order to establish the quantitative analysis of primary and secondary short-circuit melting marks and to study the influence of external heat conditions on short-circuit melting marks, X-ray diffractometer, scanning electron microscope and energy spectrometer were used to establish the evidence of electrical fire. The microstructure and composition information of short-circuit melting mark are analyzed. The experimental results show that the development trend of the grain size of the primary short-circuit melting mark is consistent with that of the heat-treatment time, and the developing direction of the grain size of the secondary short-circuit melting mark is opposite to that of the heat-treatment time under the changing trend of the specific heat treatment time. Moreover, the average value of the texture coefficient of the primary short-circuit melting mark increases at first and then decreases with the increase of the external heat temperature, and the average value of the texture coefficient of the secondary short-circuit melting mark fluctuates only in the smaller range of the numerical value. Further analysis of the chemical composition of different regions of short-circuit melting marks shows that the primary and secondary short-circuit fuses mainly contain C, O and Cu elements, and the oxygen content of the primary short-circuit melting marks is about 6% in the deposition layer of the melting marks, and the oxygen content of the primary short-circuit melting marks is about 6%. The oxygen content of the secondary short-circuit weld is about 3%, but the oxygen content of the primary-short-circuit and the second-short-circuit fusion is almost unchanged in the base region of the weld, and is about 3%, not with the external heat temperature and heat treatment time. The results show that in the electric fire at 600 鈩，
本文编号：2465826
[Abstract]:In order to establish the quantitative analysis of primary and secondary short-circuit melting marks and to study the influence of external heat conditions on short-circuit melting marks, X-ray diffractometer, scanning electron microscope and energy spectrometer were used to establish the evidence of electrical fire. The microstructure and composition information of short-circuit melting mark are analyzed. The experimental results show that the development trend of the grain size of the primary short-circuit melting mark is consistent with that of the heat-treatment time, and the developing direction of the grain size of the secondary short-circuit melting mark is opposite to that of the heat-treatment time under the changing trend of the specific heat treatment time. Moreover, the average value of the texture coefficient of the primary short-circuit melting mark increases at first and then decreases with the increase of the external heat temperature, and the average value of the texture coefficient of the secondary short-circuit melting mark fluctuates only in the smaller range of the numerical value. Further analysis of the chemical composition of different regions of short-circuit melting marks shows that the primary and secondary short-circuit fuses mainly contain C, O and Cu elements, and the oxygen content of the primary short-circuit melting marks is about 6% in the deposition layer of the melting marks, and the oxygen content of the primary short-circuit melting marks is about 6%. The oxygen content of the secondary short-circuit weld is about 3%, but the oxygen content of the primary-short-circuit and the second-short-circuit fusion is almost unchanged in the base region of the weld, and is about 3%, not with the external heat temperature and heat treatment time. The results show that in the electric fire at 600 鈩，
本文编号：2465826
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