中碳钢SWRCH35K盘条浅表面局部增碳原因分析与改进  

Analysis of the Causes of Localized Carbon Increase on the Shallow Surface of Medium Carbon Steel SWRCH35K Coils

作　　者：曾令宇 Zeng Lingyu(Steelmaking Plant,Baowu Group Guangdong Zhongnan Iron and Steel Co.,Ltd.,Shaoguan Guangdong 512123,China)

机构地区：[1]宝武集团广东中南钢铁股份有限公司炼钢厂,广东韶关512123

出　　处：《山西冶金》2024年第9期31-33,37,共4页Shanxi Metallurgy

摘　　要：分析SWRCH35K盘条浅表面“倒三角状”珠光体偏聚原因,发现铸坯浅表面局部增碳,浅表面增碳发生率26.19%,其中角部占比68.18%。研究结晶器保护渣、中间包塞棒、浸入式水口及受钢口结构、结晶器电磁搅拌参数对铸坯表面增碳发生率的影响。优化后保护渣相较于优化前保护渣,碱度降低0.11,熔化时间减少3 s,熔点升高25℃,黏度升高0.08 Pa·s,优化后保护渣渣层厚度8~11 mm。开发并应用了一种连铸中间包塞棒棒芯隔热装置和一种中间包受钢口内衬的修复方法及专用砖,同时优化浸入式水口碗部和内衬设计,实现塞棒精准控流,保证中间包和浸入式水口长寿命运行,降低结晶器液面异常波动发生率。结合上述优化结果,将结晶器电磁搅拌参数由350 A、3 Hz降低至200 A、2 Hz,实现结晶器液面波动±3 mm,铸坯表面增碳发生率由26.19%降低至3.57%。Analyzing the reasons for the "inverted triangular" pearlite segregation on the shallow surface of SWRCH35K wire rod,it was found that there was local carbonization on the shallow surface of the casting billet,with a carbonization rate of 26.19%,of which the corner accounted for 68.18%.Study the effects of crystallizer protective slag,intermediate plug rod,immersion nozzle and steel inlet structure,and crystallizer electromagnetic stirring parameters on the occurrence rate of surface carbonization of castings.After optimization,the alkalinity of the protective slag decreased by 0.11,the melting rate decreased by 3 seconds,the melting point increased by 25 ℃,and the viscosity increased by 0.08 Pa·s.The thickness of the protective slag layer after optimization was 8~11 mm.It has developed and applied a continuous casting intermediate ladle plug core insulation device,a repair method for the steel mouth lining of the intermediate ladle,and a special brick.At the same time,it has optimized the design of the immersion water outlet bowl and lining to achieve precise flow control of the plug,ensuring the long service life of the intermediate ladle and immersion water outlet,and reducing the occurrence rate of abnormal liquid level fluctuations in the crystallizer.Based on the above optimization results,the electromagnetic stirring parameters of the crystallizer were reduced from 350 A and 3 Hz to 200 A and 2 Hz,achieving a fluctuation of ±3 mm in the crystallizer liquid level and a decrease in the occurrence rate of surface carbonization of the casting billet from 26.19% to 3.57%.

关 键 词：SWRCH35K盘条 表面局部增碳 结晶器保护渣 电磁搅拌 中间包 

分 类 号：TF761.3[冶金工程—钢铁冶金]