GEN 718 Overview
GEN 718 is used for TIG welding alloys 718, 706, and X-750. It is mainly used for welding high-strength aircraft components, and liquid rocket components involving cryogenic temperatures. This alloy can be age hardened to higher strengths.
AWS Chemical Composition (Typical)
| %C | %Cr | %Ni | %Mo | %Ti | %Fe | %Mn | %B |
|---|---|---|---|---|---|---|---|
| 0.08 max. 0.045 |
17.0 – 21.0 18.5 |
50.0 – 55.0 53.8 |
2.80 – 3.30 2.90 |
0.65 – 1.15 0.95 |
Rem. 17.7 |
0.35 max. 0.05 |
0.006 max. 0.003 |
| %Si | %P | %S | %Cu | %Al | %Nb+Ta | Total Others |
|---|---|---|---|---|---|---|
| 0.35 max. 0.06 |
0.015 max. 0.007 |
0.015 max. 0.001 |
0.30 max. 0.10 |
0.20 – 0.80 0.55 |
4.75 – 5.50 5.18 |
0.50 max |
Typical Weld Metal Mechanical Properties
| Tensile Strength | 125,000 psi | 862 MPa |
| Yield Strength | 85,000 psi | 586 MPa |
| Elongation | 28% |
Typical Welding Parameters
| Process | Diameter | Voltage | Amperage | Gas/Flux |
|---|---|---|---|---|
| TIG (GTAW) | 1/16” (1.6 mm) | 14 – 18 | 90 – 130 | 100% Ar |
| 3/32” (2.4 mm) | 15 – 20 | 120 – 180 | 100% Ar | |
| 1/8” (3.2 mm) | 15 – 20 | 150 – 220 | 100% Ar | |
| MIG (GMAW) | .035” (0.9 mm) | 26 – 30 | 150 – 200 | 75% Ar – 25% He |
| .045” (1.1 mm) | 28 – 32 | 180 – 230 | 75% Ar – 25% He | |
| Sub Arc (SAW) | .093” (2.4 mm) | 28 – 30 | 275 – 350 | |
| .125” (3.2 mm) | 29 – 32 | 350 – 450 |