Abstract: Steel 26CrMoNbTiB is melted by 45 t EAF-LF ( VD) -Φ80 〜180 mm tube billet HCC flow sheet. Test results of cleanliness of the steel at each melting process showed that the oxygen content in steel after LF-VD is (8 ~ 18) x 10 ^-6 with lowest average inclusion amount i. e. 2. 31 inclusions/mm² and that is 3. 66 inclusions/mm²  in casting billet and the average content of ≥50μm micro inclusions in billet is 4. 08 mg/10 kg. To tighten the sealed shield of long nozzle from ladle to tundish, use monitoring instrument for ladle slagging out, increase tundish capacity and use dam in tundish are the key process measures to further improve cleanliness of billet。

摘要： 26CrMoNbTiB钢由45 t EAF-LF(VD)-Φ80～180mm管坯HCC流程冶炼。该钢各工序的洁净度试验结果表明,LF-VD后钢中氧含量为(8～18)×10^-6,平均夹杂物数量最低为2.31个/mm²,连铸坯平均夹杂物数量为3.66个/mm²,≥50μm大型夹杂物平均含量为4.08 mg/10 kg。加强钢包到中间包长水口的密封保护和采用钢包下渣检测装置,提高中间包容量和采用挡渣墙是进一步提高铸坯洁净度的关键工艺措施。

关键词: 钻杆管用钢26CrMoNbTiB, EAF-LF(VD)-HCC, 洁净度