冶炼硼钢控制硼含量的工艺实践

Process Practice for Control of Boron Content in Boron Steels during Steelmaking

23～40MnB和27MnTiB等硼钢的炼钢流程为50 t EAF-LF+VD-CC工艺。通过控制EAF终点[C],出钢时用碳粉、钢芯铝、硅锰预脱氧,LF精炼前钢水溶解氧≤20×10^(-6),精炼渣碱度≥3.5,喂铝线控制LF末(FeO)+(MnO)≤1.5%,(SiO_2)≤15%,LF终点[Al]≥0.020%,喂钛铁包芯线,控制[Ti]0.030%～0.050%,同时喂硅钙包芯线控制钢中夹杂物形貌,并在VD脱气处理前底吹氩搅拌加入硼铁或喂入硼铁包芯线可有效地提高硼回收率至90%以上。

The steelmaking flow sheet for boron steels such as 23 ~ 40MnB and 27MnTiB etc is 50 t EAF-LF ＋ VD-CC process. It is available to increase the yield of boron to more than 90% by controlling EAF end [C], preliminary deoxidation by adding carbon powder, steel-cladding aluminium and silicon-manganese at tapping and before LF refining the solution oxygen in liquid ≤20 × 10^-6, controlling LF refining slag basieity ≥3.5 and feeding aluminium wire to control LF end （FeO） ＋ （MnO）≤1.5 % and （ SiO2 ） ≤ 15 %, LF end [ A1 ]≥ 0. 020%, feeding steel-cladding titanium to control [ Ti ] 0. 030% - 0. 050% and feeding cladding silicon-calcium wire to control the morphology of inclusions in steel, and before VD degassing treatment, bottom-blowing argon stirring and adding ferroboron or feeding cladding boron wire.