4330M, 4330 MOD, 4330V is a low alloy high strength steel melted as AOD + VAR or EAF+LF+VD+VAR. It has added vanadium which improves impact strength as well as hardenability. It's high strength and excellent fatigue strength lends itself to demanding aerospace applications similar to 4340 and 300M. has alloy steel are used in aircraft landing gears, shafts or axels for power transmission and gears.
AOD + VAR
EAF+LF+VD+VAR
| Grade | Chemical composition WT % | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | Cr | Mo | Al | Ni | V | Cu | Ti | O2 | N2 | |
| 4330V, UNS K23080 | 0.31 - 0.33 | 0.15 - 0.35 | 0.80 - 0.95 | Max 0.015 | Max 0.005 | 0.8 - 1.0 | 0.45 - 0.50 | 0.015 - 0.035 | - | 0.06 - 0.10 | ||||
| 4330M | 0.48 - 0.53 | 0.15 - 0.35 | 0.75 - 1.00 | Max 0.035 | Max 0.04 | 0.8-1.1 | 0.15 - 0.25 | |||||||
| 4330 MOD, UNS K23080 | 0.28 - 0.33 | 0.15 - 0.35 | 0.40 - 0.60 | Max 0.010 | Max 0.002 | 0.80 - 1.10 | 0.15 - 0.25 | - | Max 0.25 | 0.05 - 0.10 | Max 0.07 | Max 0.005 | Max 0.002 | Max 0.005 |
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | ≥ 860 MPa | ≥ 125000 psi |
| Yield strength | ≥ 690 MPa | ≥ 100000 psi |
| Elongation at break (In 50 mm) | ≥ 15.0 % | ≥ 15.0 % |
| Hardness, Brinell | 285 | 285 |
| Properties | Metric | Imperial |
|---|---|---|
| Melting point | 1427°C | 2600°F |
4330 alloy steel is heated to 829°C (1525°F) and then quenched in oil. 4330 alloy steel can also be heat treated to strength levels of 200 ksi or greater than 200 ksi, by first being normalized at 899°C (1650°F) before the heat treatment and then quenched to gain strength.
Forging: 1230-1070 °C
Rolling: 1230-1070 °C
Annealing: 820-860 °C
Conventional methods are used for welding 4330 alloy steel. 4330 alloy steel is preheated and post heated based on the welding procedure used for this alloy steel type, and the alloy can be joined by a brazing process.
4330 alloy steel has good machinability features in the annealed, tempered and normalized conditions. This alloy steel is difficult to be machined in the hardened condition.
Steel grade
Special steel