【作者】 鲍道华； 成国光； 陈兴润； 乔通； 潘吉祥；

【Author】 BAO Daohua;CHENG Guoguang;CHEN Xingrun;QIAO Tong;PAN Jixiang;State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing;Hongxing Iron and Steel Co.,Ltd.,Jiuquan Iron and Steel Group Corporation;

【机构】 北京科技大学绿色低碳钢铁冶金全国重点实验室； 酒钢集团宏兴钢铁股份有限公司；

【摘要】 本文探究了2507双相不锈钢表面起皮缺陷的特征和形成机理,并分析了冶炼工艺对起皮缺陷的影响。研究发现,板材表面缺陷主要为起皮缺陷。在缺陷处存在大量的CaO-Al₂O₃-SiO₂类夹杂物,其平均成分为:39%CaO、34%Al₂O₃和27%SiO₂。单个夹杂物的尺寸主要在20μm以上,聚集型夹杂物的尺寸可达200μm。这些大尺寸和聚集型夹杂物是导致起皮缺陷的直接原因,它们的形成与冶炼工艺有关。当AOD还原期钢中Si含量较低时,Si还原渣中Cr₂O₃不充分,造成钢中O含量较高,从而导致AOD脱硫期和LF阶段钢中较低的Al含量。而炉渣成分设计的不合理又进一步降低了钢中Al含量。当Al含量小于0.006%时,会促使内生CaO-Al₂O₃-SiO₂类夹杂物的形成。这类夹杂物不易从钢液中去除,最终会遗传到板材中。通过提高Al含量可以有效抑制CaO-Al₂O₃-SiO₂类夹杂物的形成,但需要对整个冶炼工艺进行优化。更多还原

【Abstract】 In this paper,the characteristics and causes of surface peeling defects in 2507 duplex stainless steel are investigated.The effect of the smelting process on these defects was analyzed.The surface defects of the sheet are mainly peeling defects.A significant number of CaO-Al₂O₃-SiO₂ inclusions are identified in the defects,with an average composition of 39% CaO,34%Al₂O₃,and 27% SiO₂.The size of individual inclusions is generally above 20 μm,while the size of aggregated inclusions can reach up to 200 μm.These large and aggregated inclusions are the direct causes of the peeling defects.Their formation is associated with the smelting process.When the Si content in the steel during the AOD reduction stage is low,Si insufficiently reduces Cr₂O₃ in slag.This results in higher O content in the steel and subsequently lower Al content during the AOD desulfurization stage and LF stage.The unreasonable design of slag composition further diminishes the Al content in the steel.When the Al content is less than 0.006%,it promotes the formation of endogenous CaO-Al₂O₃-SiO₂ inclusions.These inclusions are difficult to remove from the liquid steel and are eventually inherited into the sheet.Increasing the Al content can effectively inhibit the formation of CaO-Al₂O₃-SiO₂ inclusions,but the entire smelting process needs optimization.更多还原