The main reasons of 5 t ingot carbon-pickup and low desulphurization ratio for pure iron during electroslag remelting (ESR) process are analyzed. With the process measures including to replace original remelting slag (% ) ~70 fluorite
~30 alumina powder
3 -7SiO
2
0. 05 ~0. 09C by new remelting slag (% ) 65 fluorite
25 alumina powder
10 limestone
≤SiO
2
≤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 original 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-ultral-low sulfur prue iron YT01B.