连铸结晶器喂稀土处理的碳锰钢夹杂物研究

Inclusions of C-Mn Steels in Continuous Casting Crystallizer by Rare Earths Treatment

为研究钢中添加稀土带来的夹杂物问题,采用金相夹杂物评级、电解夹杂分析以及电子探针和扫描电镜观察分析,对经稀土处理的微合金化碳锰钢夹杂物进行了研究。结果表明,采用铝脱氧和RH真空充分脱气的微合金化碳锰钢,经连铸结晶器喂稀土处理后,钢中的A,B,C,D类夹杂物分别不大于1.0级、1.5级、0.5级、1.5级,氧化物夹杂总量约为0.0030%。试验钢中主要形成球状稀土硫化物,同时还形成有链状"稀土硫化物包围氧化铝"的复合夹杂物,而稀土氧化物难以生成。

The inclusions in microalloying C-Mn steels with rare earths treating were investigated by means of optical microscopy,electrolytic inclusion analysis,EPMA and SEM.The results showed that the A,B,C and D type inclusions in the trial steels,which were treated by aluminum deoxidizing and RH vacuum degassing and then were fed by core-spun yarn of rare earths in continuous casting crystallizer,were not more than 1.0,1.5,0.5,1.5 grade respectively,and the total amount of oxide inclusions was about 0.0030%.The inclusions in the trial steel were mainly spherical rare-earth sulfides and chain compound inclusions of alumina surrounded by rare-earth sulfide,and at the same time,the rare earth oxides were difficult to generate.