转炉-连铸工艺流程生产高合金钢Mn13技术开发及应用

Technological Development of High-alloy Steel Mn13 by Converter-Continuous Casting Process and Its Application

通过优化转炉-连铸工艺路线,精准控制钢水冶炼成分,进行了高合金钢Mn13的生产探索。结果表明,铁水预脱硫利用KR控制出站w [S]≤0.002%;转炉出钢w [P]≤0.012%,合金总量的1/3在转炉出钢时加入,其余在精炼LF完成,RH控制出站钢水w[H]<0.000 2%,w[N]<0.008 0%;连铸工序控制拉速为0.8~1.0 m/min,结晶器宽边水量为3 900~4 100 L/min,窄边水量为560~590 L/min;连铸结束后需做好封顶工作。采取上述措施后,高合金钢Mn13成坯合格率从原来的50%以下提升到95%以上。

By means of optimizing the process route for converter-continuous casting,precisely controlling the compositions in molten steel,the investigations for producing the high-alloy steel Mn13 was carried out.The results showed that the content of sulfur in hot metal in pretreatment process should be controlled less than 0.002%by KR method,while tapping from the converter the content of phosphorus in molten steel should be controlled less than 0.012%.At the same time one third of total amount of alloy should be added just in tapping from the converter and the rest alloy added during LF process,and the content of both hydrogen and nitrogen in molten steel at the end of RH process should be controlled less than 0.0002%and 0.0080%respectively.As for the operating procedures on continuous casting,the casting speed should be controlled in the range from 0.8 m/min to 1.0 m/min,while the water volume at the broad brim of the crystallizer should be controlled in the range from 3900 L/min to 4100 L/min,the water volumeat the narrow brim in the range from 560 L/min to 590 L/min.At last,the capping operation should be done well after finishing continuous casting process.After the above-metioned measures were taken the pass percent of finished casting blanks made of the high-alloy steel Mn13 was improved to over 95%from less than 50%.