高钛焊丝钢ER70S-G冶炼工艺优化实践

Practice of smelting process optimization of high titanium welding wire steel ER70S-G

高钛焊丝钢ER70S-G研发时经常出现水口结瘤、结晶器“结鱼”、铸坯夹渣等问题,尤其是铸坯夹渣导致轧制后盘条表面出现连续性锯齿状结疤缺陷,严重影响盘条表面质量。引起水口结瘤、结晶器“结鱼”的主要原因是存在TiO_(x)、TiN等高熔点非金属夹杂物。通过控制钢水中氧氮含量、使用纯净合金、降低渣中SiO_(2)活度、调整钛合金化时机及温度等手段,解决了水口结瘤、结晶器“结鱼”、铸坯夹渣等问题,将高钛焊丝钢ER70S-G连浇炉数提高至10炉,盘条成材率提高至97%,优化效果显著。

During research and development of high titanium welding wire steel ER70S-G,problems such as nozzle nodule,crystallizer floater,billet slag and so on often occur,in particular,billet slag leads to continuous serrated scar defect on wire rod surface after rolling,which seriously affects surface quality of wire rod.It is considered that non-metallic inclusions with high melting point,such as TiO_(x) and TiN,are main causes of nozzles nodule formation and crystallizer floater formation.By controlling content of oxygen and nitrogen in molten steel,using pure alloy,reducing activity of SiO_(2) in slag,adjusting time and temperature of titanium alloying,etc.,the problems such as nozzle nodule,crystallizer floater and billet slag were solved.The number of continuous casting furnaces for high titanium welding wire steel ER70S-G was increased to 10 furnaces,and yield of wire rod was increased to 97%,optimization effect is significant.