纯铁电渣重熔的碳-硫控制

Control of Carbon and Sulfur Content in Electroslag Remelting Pure Iron

分析了5t锭纯铁电渣重熔过程增碳和脱硫率低的原因。通过将～70%萤石、～30%氧化铝粉、3%～7%SiO_2、0.05%～0.09%C的原渣系改成65%萤石、25%氧化铝粉、10%生石灰、≤1%SiO_2、≤0.02%C的新渣系,采用1t电渣锭并将结晶器填充比由30%提高到45%、电渣重熔过程向渣中加铝粉等工艺措施,使电渣重熔纯铁的最大增C量由0.067%降至0.001%,平均脱硫率由41%～46%增至53.4%～78.0%,电渣锭碳、硫含量均≤0.003%,满足了超低碳-超低硫纯铁YT01B的质量要求。

The main reasons of 5 t ingot carbon-pickup and low desulphurization ratio for pure iron during electroslag remehing （ESR） process are analyzed. With the process measures including to replace original remelting slag （%） -70 fluorite, -30 alumina powder, 3 -7SiO2, 0. 05 -0. 09C by new remelting slag （%） 65 fluorite, 25 almnina pounder, 10 limestone, ≤SiO2 , ≤0.02C; adopting the process measures such as using 1 t ESR ingot with increasing mold packed ratio from 30% to 45% , and adding aluminum powder during electroslag remelting, the maximum carbon-pickup in ESR pure i- ron decreases to 0. 001% from original 0. 067% , the average desulphurization ratio increases to 53.4% -78% from origi- nal 41% -46% and the carbon and sulfur content in ESR ingot are all ≤0. 003% , to meet the requirements of quality of ultra-low carbon-uhral-low sulfur prue iron YT01B.