4343, UNS G43406 is a low alloy steel with ultra high strength melted as VIM + VAR product. It also possessed good toughness and fatigue strength when heat treated. This alloy has just slightly higher carbon than 4340 low alloy steel. This grade also displays excellent transverse properties even in larger cross sections and is often used in the rotorcraft aerospace market.
VIM + VAR
| Grade | Chemical composition WT % | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | Mn | P | S | Cr | Mo | Al | Ni | V | |
| 4343 | 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 |
| UNS G43406 | 0.38 - 0.43 | 0.15 - 0.35 | 0.65 - 0.85 | Max 0.025 | Max 0.025 | 0.7-0.9 | 0.2 - 0.3 | 1.65-2.00 | ||
| 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 |
4343 alloy steel is heated to 829°C (1525°F) and then quenched in oil. 4343 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 4343 alloy steel. 4343 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.
4343 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