Leaf and volute springs, road and railway vehicle springs including helical and plat spring. This steel is capable of taking up a good hardness and possesses an increased stability in tempering.
Typical Analysis In %
| C |
Si |
Mn |
Cr |
W |
V |
Co |
Mo |
Ni |
| 0.50/0.60 |
1.50/2.00 |
0.70/1.00 |
- |
S&P each 0.05 (max) |
- |
- |
Heat Treatment & Processing
| Forging Temp. °C |
Annealing Temp. °C |
Hardening Temp. °C |
Quenching Medium |
Tempering Temp. °C |
Hardness Rockwell °C |
| 900-830 |
650-680 |
830-860 |
O |
470-540 |
BHN 235 |
Equivalent Grades
| BS 970 (REVISED) 1970-1972 |
BS 970-1955 En No. |
AISI/SAE |
DIN |
Japan |
U.S.S.R. |
IS |
| 250A53 |
45 |
9255 |
55Si7 |
- |
55C2 |
| Grade |
Specification |
| T55Si7 |
3749/1978 |
|
High duty volute and leaf springs, Heavy engine valve springs, helical and torsional bar springs. It has a high ratio of yield point to tensile strength and high torsional fatigue strength.
Typical Analysis In %
| C |
Si |
Mn |
Cr |
W |
V |
Co |
Mo |
Ni |
| 0.45/0.55 |
0.5 |
0.50/0.80 |
0.80/1.20 |
- |
0.15 (max) |
S&P each 0.05 (max) |
- |
Heat Treatment & Processing
| Forging Temp. °C |
Annealing Temp. °C |
Hardening Temp. °C |
Quenching Medium |
Tempering Temp. °C |
Hardness Rockwell °C |
| 900-830 |
650-680 |
830-860 |
O |
470-540 |
BHN 235 |
Equivalent Grades
| BS 970 (REVISED) 1970-1972 |
BS 970-1955 En No. |
AISI/SAE |
DIN |
Japan |
U.S.S.R. |
IS |
| 735A50 |
47 |
6150 |
50CrV4 |
- |
- |
| Grade |
Specification |
| T50Cr4V2 |
3749/1978 |
|