【摘要】 报道了一种新颖的热剂焊接方法,采用该种热剂焊接方法可以在无电条件下,不借助任何辅助设备,便可十分方便的进行手工焊接作业。通过分别添加不同含量的微硅粉和硅灰石作为稀释剂对热剂反应进行调控,获得了不同燃烧速率的热剂焊条;对在不同燃烧速率下焊接所得的焊接接头进行了显微组织分析。结果表明:在高的燃烧速率下焊接时,焊缝组织中易出现缩松和夹渣缺陷;随着燃烧速率的降低,焊缝显微组织中的缩松和夹渣缺陷逐渐消除;当燃烧速率进一步降低时,焊缝组织中开始出现大量气孔缺陷。分析表明:这种显微组织的演变与不同燃烧速率下焊接熔池所经历的升温过程有关。更多还原

【Abstract】 A novel method of thermite welding was presented. A hand-operated portable welding can be conveniently realized by using thermite welding pencil without any outside energy sources and auxiliary equipments. Different thermite burning rates were obtained by varying addition of micro-silica fume and wollastonite as diluent respectively. The results show that massive shrinkage porosities and inclusions were formed in the fusion zone at high burning rate. With decreasing burning rate, those defects disappeared gradually. However, with further decreased burning rate, lots of porosities were obtained in the fusion zone. The investigation demonstrates that the change in microstructure of weld is most likely related to the solidification process of weld pool at different burning rates.更多还原