The structure of high stength-toughness spring steel 38SiMnVB -0.39C

1.48Mn

1.21Si

0.09V

0.0019B was pearlite + ferite with grain size less than No 10

HRC value 26

tensile strength 925～1010 MPa and elongation 45%～58% by finishing rolling between 750 ℃ and 820 ℃ with finished temperature 700~720 ℃ than slow cooling.After rolled it could be cold drawn directly.With 870 ℃ quenched and 320 ℃ tempered the super-fine grain spring steel 38SiMnVB as a spring for cars had excellent comprehensive mechanical properties-tensile strength 2030～2140 MPa

yield stength 1900~2010 MPa

elongation 12%～15%

reduction of area 48%～55%.