Abstract: The experimental data of 400 heats of steel produced by 110 t EAF + LF/VD refining + continuous casting + hoi rolling in a special steel plant are statistically analyzed. The hardenability [at (920 ± 10) °C for 50 min and then air cooling to room temperature,followed by holding at (880 ±5) °C for 30 min water quenching] and chemical composition of 20CrMnTiH steel are obtained by means of Jominy test and spectral analysis to get a linear relationship between the hardenability and the content of residual boron. By each steelmaking practice analysis it is found that the main source of B in steel is EAF tapping slag. The content of B in steel can be effectively controlled by controlling the amount of tapping slag in EAF tapping. In addition, when the amount of Al₂O₃ in the refining slag decreases from 30 % to 15% ~20% ,the content of B in steel can be controlled below 0. 000 2%.

摘要： 通过对特钢厂经110 t电弧炉+LF/VD精炼+连铸+热连轧工艺流程生产的400炉钢棒材的数据进行统计,利用末端淬透性实验[（920±10）℃50 min后空冷至室温,随后（880±5）℃ 30 min水淬]和光谱分析获得了20CrMnTiH系列钢的淬透性和化学成分,发现淬透性与残余硼元素存在线性关系。通过对各冶炼工序的分析,得出钢中B的主要来源是电弧炉下渣,控制电弧炉出钢下渣量,可以有效控制钢中B含量。此外,还须将精炼渣中Al₂O₃含量从～30%降至15%～20%,可将钢中B含量控制在0.000 2%以下。