低碳钢盘条氧化铁皮形成机理及其控制研究

Research on the Forming Mechanism and Control of Oxide-scale of Low Carbon Steel Wire Rod

低碳钢盘条表面氧化铁皮的质量是影响冷拉丝前除磷效果影的主要因素之一,采用热模拟试验机研究了对低碳钢盘条在不同加热温度和冷却工艺下形成氧化铁皮的厚度、显微组织、相结构及其组成成分、相对含量和分布特征,分析出了生成氧化铁皮控制方向和理想的吐丝温度和冷却工艺。研究结果表明,温度过高,生成氧化铁皮疏松易脱落,温度过低,生成氧化铁皮太薄起不到保护作用;冷却速度越快,生成氧化铁皮越致密,表面质量越好,Fe3O4层的厚度较厚,冷却速度过快则氧化皮就过薄。终轧温度950℃、吐丝温度930℃、冷却速度0.5~1℃/s的冷却工艺能得到厚度适中,致密度较高的氧化铁皮,且容易机械除鳞。

The quality of surface oxide-scale of low carbon steel wire rod is one of main influence factors for mechanical descaling before drawing. By means of thermal simulation test machine, the author researched the oxide-scale thickness, microstructure, phase structure and its composition, the relative content and distribution characteristics formed under different heating temperature and cooling rate in rolling process for the low carbon steel wire rod. The results showed that the oxide-scale would be loose and easy to fall off when rolling temperature too high, the oxide-scale would be too thin to play protecting function when rolling temperature too low. The larger the cooling rate is, the denser the oxide-scale is, the better the rod surface quality is and the thicker the ferroferric oxide layer is, and the oxide-scale would be too thin if the cooling rate is too large. When the final rolling temperature is 950 ℃, the laying temperature is 930 ℃, the cooling rate is 0.5-1℃ /s, the oxide-scale with moderate thickness and higher density can be obtained and descaled easily.