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