弹簧钢洁净化生产工艺研究

Research on Clean Production of Spring Steel

采用系统取样,结合金相观测、全氧分析、大样电解、电子探针和稀土氧化物示踪等手段,对八钢电炉厂电弧炉—LF—小方坯连铸生产60Si2Mn的洁净度进行了系统研究,精炼后钢液w(TO)为95×10-6,中间包内w(TO)为94×10-6,铸坯中w(TO)为54×10-6。了解了各阶段夹杂物数量、尺寸分布和类型,找出了大型夹杂物的来源。根据影响钢质量的主要因素,提出了有针对性的改进方案,优化设置了控流装置。改进后,钢中有害夹杂物数量大大减少,质量明显提高,铸坯w(TO)由54×10-6下降到28×10-6。

With systematic sampling in each process, the cleanliness of 60Si2Mn produced by EAF（electric arc furnace）-LF（ladle furnace）-CC（continuous casting） route at Bayi Steel was studied by metallographical observation, oxygen analysis, large sample electrolysis, EPMA, rare earth oxides tracing, etc. It was found that total oxygen content of liquid steel was 95×10^-6 after LF refining, 94×10^-6 in tundish and 54×10^-6 in billet respectively. The amount, size distribution and type of inclusion at different stages were investigated, and the source of large inclusions was also found. Based on the research results, some useful suggestions were proposed aiming at the main affecting factors of steel cleanliness, and the flow control device in tundish was optimized. After modification, the amount of harmful inclusions was decreased, and the quality of spring steel was greatly improved, and the content of total oxygen was reduced to 28 ×10^-6 from 54×10^-6.