Fe_2SiO_4相析出行为对焊线钢丝表面镀铜的影响

Effect of Fe_2SiO_4 phase precipitation behavior on surface copper of welding wire

采用扫描电镜(SEM)、背散射电子成像(BSE)的方法,研究了Fe_2SiO_4相析出行为对焊线钢丝表面镀铜的影响。结果表明:在工业加热炉气氛(残氧≤2.5%)条件下,形成的液态Fe_2SiO_4相酸洗难以去除,且在高线多道次轧制及用户多道次拉拔后具有遗传性,是镀铜层呈现暗灰色或黑色的原因。在试验钢Si含量为0.9 mass%的条件下,在温度≤1150℃时,Si元素对氧化有阻碍作用;在温度>1150℃时,Fe2Si O4相熔化成为氧、铁离子的快速扩散通道,与FeO呈相互包裹状态成为酸洗难以去除的FeO-Fe_2SiO_4相。

Effect of Fe2SiO4 phase precipitation on copper plating of welding wire was investigated by scanning electron microscopy（SEM）and back scattered electron（BSE） imaging.The results indicate that liquid Fe2SiO4 phase forms under industrial furnace atmosphere（residual oxygen ≤2.5%） which is difficult to remove by pickling.Moreover,the liquid Fe2SiO4phase has certain heredity thus it exists after high line multi-pass rolling and drawing process which induce black or dark gray copper layer on the wire.Under the condition of the testing steel with Si content of 0.9 mass%,when temperature is less or equal to 1150 ℃,Si hindered the formation of ferrous oxides.When temperature is greater than 1150 ℃,Fe2SiO4becomes liquid and accelerates diffusion of oxygen and iron ions,and forms FeOFe2SiO4 which is hard to remove after pickling.