模拟火灾现场中铜包钢导线熔痕产生的条件,制备一、二次短路熔痕和火灾热作用导线痕迹。使用金相分析法,寻找最佳金相浸蚀剂,研究一、二次短路熔痕的金相组织特点。结果表明,4%硝酸酒精是最佳浸蚀剂,一次短路熔痕的组织以较细的马氏体为主,及少量暗色托氏体,存在气孔;二次短路熔痕中以马氏体为主,晶界处有铁素体析出,不存在托氏体,几乎没有气孔存在。 Simulate the conditions of the copper clad steel wire weld marks in the fire scene and prepare the first and second short-circuit weld marks and the thermal trace traces of the fire. Metallographic analysis was used to find the best metallurgical etchant to study the microstructure of primary and secondary short-circuit weld marks. The results show that 4% nitric alcohol is the best etchant. The microstructure of a short-circuit weld is mainly martensite with a small amount of dark-colored tuff. There are pores in the secondary short- Mainly ferrite precipitation at the grain boundaries, there is no presence of Tungsten, almost no pores exist.