Abstract: EAF→LF→VD technological test was conducted to replace VIM-ESR in order to increase the production efficiency and to reduce process cost of over 2 000 MPa grade ultrahigh strength low alloy steel for mass production capacity. The test result shows that the total mass fraction of O, N and H in steel is smaller than 50×10-6；the nonmetallic inclusion of A, B and C class is evaluated as 0 grade and class D inclusion is less than 1.0 grade. The tensile strength of finished steel plate is more than 2 100 MPa after quenching and low tempering and its elongation is greater than 7 %, which is equivalent to the result of using VIMESR technology. By using the new technology, the cost is reduced by over 44 % and the production efficiency is increased. The new technology is suitable for large-scale production of ultra-high strength low alloy steel.

Key words: ultra-high strength steel, electric arc furnace, refining, technological test