The metallurgy flowsheet of developed steel Q460D (/% : 0. 16 - 0. 18C

0. 42 ~ 0.48Si

1.40 ~ 1.46Mn

0.012 ~0. 020P

≤ 0.005S

0.11 ~12V

0.020 ~ 0.050A1

0.0102 ~0.0139N) is ≥40% hot metal + scrap- 50 t EAF-LF-VD-260 mm x 300 mm bloom casting- hot rolling to 070 ~ 100 mm products. With the process measures including controlling EAF end [C] 07% and [P]≤0.015%

LF refining slag basicity ≥ 3.0

feeding Al and Ca wire

controlling Al 0. 030% ~ 0. 05% and [S]≤0.005%

and feeding manganese-nitride wire before LF tapping

the mechanical properties of steel is stable i. e. yield and tensile strength

elongation and impact energy of steel being respectively 470 - 504 MPa

576 ~ 695 MPa

19.0% ~ 27. 5% and 32 ~ 60 J

the qualified rate of nondestructive testing is 93. 7%

and the stability of composition and each performance of steel is high to meet the of high cleanliness

high homogeneity and high stability of properties of steel for auto axle head.