Abstract: Based on the analysis of 55SiCrA spring steel produced by "120 t LD → LF→ RH →150 mm x 150 mm continuous casting billet → wire rolling” process, the thermodynamic calculation is carried out by using Factage thermodynamic calculation software to optimize the refining process. The results show that the inclusions in CaO-SiO₂ -Al₂O₃ system can be transformed into plastic inclusions with the content of SiO₂ 41% ~ 46% , CaO 36% ～ 41% ,Al₂O₃ 0% ~3% , MgO 10% refining slag and slag basicity 0. 8～1. 0. Using low Ti, Al alloy and non-aluminum refractory material, the smelting end [Al] reduces to 0.0018% ~ 0. 0022% , [Ti ]reduces to 0.001 0% ~ 0. 001 2% , the undeformed inclusions such as aluminum magnesium spinel and TiN in the steel are obviously reduced, the content of Al2O3 in the inclusions is reduced to about 15%. The inclusion ingredient are all located in the low melting point region.

摘要： 在分析"120 t LD→LF→RH→150 mm×150 mm连铸坯→线材轧制"工艺流程生产的弹簧钢55SiCrA的基础上,应用Factsage热力学计算软件进行热力学计算,对精炼工艺进行优化研究。结果表明:精炼渣系中含SiO₂ 41%～46%、CaO 36%～41%、Al₂O₃ 0%～3%、MgO 10%,渣碱度0.8～1.0,可使CaO-SiO₂-Al₂O₃系夹杂物成为塑性夹杂物。使用低Ti、低Al合金及无铝耐材,冶炼终点[Al]降至0.001 8%～0.002 2%,[Ti]降至0.001 0%～0.001 2%,钢中铝镁尖晶石和Ti N等不变形夹杂物明显降低,夹杂物中Al₂O₃含量降至15%左右,夹杂物成分全部位于低熔点区。

关键词: 弹簧钢 55SiCrA, 精炼渣, 夹杂物塑性化