电渣重熔工艺对GH4169脱硫的影响

Effect of Electroslag Remelting Process on Desulphurization of GH4169

为进一步降低GH4169中的硫含量,进行了大气下、氩气氛保护及氩气氛保护下向渣池加钙精炼3种工艺条件对脱硫效果影响的电渣重熔试验。结果表明,大气下重熔时脱硫效果明显,硫含量(质量分数,下同)由18×10-6降低到6×10-6,渣中的硫通过气化反应脱除;氩气氛保护不利于电渣重熔工艺的脱硫,硫含量降低到7×10-6后提高到9×10-6,熔渣中的硫不断富集;硫分配比的计算值与实测值的对比研究表明,电渣重熔脱硫热力学条件优越,动力学条件是限制实际脱硫效率进一步提高的主要因素;氩气氛保护下通过向渣池加钙后,熔渣中钙元素能够对合金进行脱硫且脱硫率有较大幅度的提升,合金中硫含量随钙含量的增加而减少,重熔结束时硫含量降至3×10-6。

For further reducing sulphur content in GH4169,three experimental electroslag remelting（ESR） process [in air,under inert gas protection（PESR） and inert gas protection with Ca addition in slag pool] were taken for desulphurization of GH4169.The results indicate that desulphurization via ESR in air is excellent,sulphur content can be reduced from 18×10-6 in electrode to 6×10-6 in ingot and the sulphur in slag is decreased by gasification;desulphurization via PESR influenced by accumulating sulphur content in slag,sulphur content in ingot is increased from 7×10-6 to 9×10-6.By comparing calculated LS and measured LS,it is show that thermodynamic condition is perfect for desulphurization,and reality desulphurization is limited by dynamic condition.For PESR with Ca addition in slag pool,calcium can remove sulphur to improve desulphurization.During remelting,calcium content in ingot increases and sulphur content decreases continually.Finally,sulphur content can be reduced to 3×10-6.