含硼中碳钢的保护渣

Casting Powder of Medium Carbon Steel Containing Borbon

针对含硼中碳钢铸坯角部裂纹问题,通过检测保护渣凝固液渣层硼含量发现钢中硼的质量分数为0.001 3%时,进入渣中B2O3的质量分数为0.74%,并测得原渣样和液渣样粘度分别为0.122、0.12Pa·s(1 300℃),认为钢中硼含量对保护渣性能影响较小,无需针对含硼钢设计特殊保护渣。对原中碳钢保护渣性能进行了优化,碱度(R)从1.23增加到1.27;1 300℃下粘度从0.165Pa·s降低到0.123Pa·s;1 350℃下熔速从22kg/h增加到27kg/h;熔点从1 085℃增加到1 155℃,铸坯角部裂纹得到了明显的控制。

Aimed at the problem of corner crack of medium carbon steel containing boron, by analyzing the boron content in concretion fluid slag blanket of casting powder, it was found that, when the boron content in steel is 0. 001 3%, the percentage composition of B2O3 in slag is 0.74%, and the viscosity of original slag specimen and fluid slag specimen is 0. 122 Pa·s and 0.12 Pa·s （1 300℃）, respectively. The content of borbon in steel has little influence on the per- formance of casting powder, and it is needless to design special casting powder for boron steel. The performance of original medium carbon casting powder has been optimized.. R increases from 1. 23 to 1. 27, viscosity decreases from O. 165 Pa·s to O. 123 Pa·s （1 300℃）, melting speed increases from 22 kg/h to 27 kg/h, fusion point in- creases from 1 085 ＂C to 1 155℃, and the corner crack of casting blank is obviously well controlled.