Fe_2O_3对自保护药芯焊丝性能的影响

Effect of Fe_2O_3, on self-shielded flux cored wire

通过改变自保护药芯焊丝药芯中Fe2O3的加入量,系统地研究Fe2O3对预处理剂熔点、熔敷金属残留铝含量、焊缝的力学性能和断口的影响。结果表明,在一定范围内,随着药芯中Fe2O3含量的增加,预处理药粉的熔点增高,熔敷金属残留铝量减少,焊缝的抗拉强度和屈服强度下降而延伸率和低温冲击韧度提高,拉伸试棒的韧窝断口比例增加,夹杂物的尺寸和数量减少。焊缝中的夹杂物是由Ba、Ca、Al、Mg为主的复合夹杂物,形态以圆形和长形为主。但是,Fe2O3的加入量是有一定限制的,当Fe2O3的加入量大于焊丝总量的4.5%时,焊丝在焊接过程中对电弧电压十分敏感,甚至出现气孔。综合考虑焊接工艺性能和力学性能,药芯中Fe2O3的加入量应该占焊丝总重的2.5%～3.5%。

The effect of Fe2O3 on retained aluminum in deposited metal, mechanical properties and fracture analysis has been elucidated. The results show that with the increasing of Fe2O3 in the flux core, the melting point of the pretreated compounds, the content of retained aluminum in deposited metal, the size and the number of inclusion, yield strength and tensile strength decrease, while the toughness of the deposited metal and the dimple proportion of the fracture increase. The inclusions in the weld are Ba,Ca,Al,Mg in round and rectangular form predominantly. However, electrode with the Fe2O3 content exceeding 4.5% is extremely sensitive to voltage and macro-porosity can be found in the weld metal. So, in the view of the processing properties and the mechanical properties, the range of 2.5-3.5 percent by weight of core to electrode is preferred.