2.4668
Data sheet material 2.4668 / Alloy 718
NiCr19Fe19Nb5Mo3
Nickel-chromium-iron-molybdenum alloy
Brief description
The material 2.4668 or Alloy 718 is a nickel-chromium-iron-molybdenum alloy with the addition of niobium and low proportions of aluminium and titanium. This material is available solution-annealed and hardened. It is characterised by good corrosion resistance at high and low temperatures and very good creep rupture strength.
Standards and nomenclature
| EN | |
|---|---|
| DIN | NiCr19Fe19Nb5Mo3 |
| AISI | Alloy 718, INCONEL® 718 |
| US | N07718 |
| EN | |
|---|---|
| DIN | NiCr19Fe19Nb5Mo3 |
| AISI | Alloy 718, INCONEL® 718 |
| US | N07718 |
Chemical composition
| Ni (nickel) | 50,0 | 55,0 |
| Cr (chromium) | 17,0 | 21,0 |
| Fe (iron) | bal. | bal. |
| C (carbon) | - | 0,08 |
| Mn (manganese) | - | 0,35 |
| Si (silicon) | - | 0,35 |
| Cu (copper) | - | 0,30 |
| Co (Cobalt) | - | 1,0 |
| Ti (titanium) | 0,65 | 1,15 |
| Al (aluminium) | 0,2 | 0,8 |
| P (phosphorus) | - | 0,015 |
| Mo (molybdenum) | 2,8 | 3,3 |
| B (boron) | - | 0,006 |
| Nb (niobium) | 8,0 | 10,0 |
| S (sulphur) | - | 0,015 |
| Ta (tantalum) | - | 0,05 |
-
-
min.
max.
Ni
(nickel)
50,0
55,0
Cr
(chrome)
17,0
21,0
Fe
(iron)
bal.
bal.
C
(carbon)
-
0,08
Mn
(Manganese)
-
0,35
Si
(Silicon)
-
0,35
Cu
(copper)
-
0,30
Co
(Cobalt)
-
1,0
-
-
min.
max.
Ti
(Titanium)
0,65
1,15
Al
(aluminium)
0,2
0,8
P
(phosphorus)
-
0,015
Mo
(Molybdenum)
2,8
3,3
B
(boron)
-
0,006
Nb
(niobium)
8,0
10,0
S
(sulphur)
-
0,015
Ta
(Tantalum)
-
0,05
General properties
| Corrosion resistance | |
|---|---|
| Mechanical properties | good |
| Weldability | excellent |
Special properties
Solution-annealed condition: good processing properties
Hardened state: high fatigue strength
Excellent mechanical properties at low temperatures
Good resistance to oxidation up to 1000°C
Good creep strength up to 700°C
Corrosion resistance
Due to the high proportion of nickel, chromium and molybdenum, the material 2.4668 has good resistance to pitting and stress corrosion cracking. The high number of different alloying elements make Alloy 718 resistant to a wide range of corrosive media.
Mechanical properties
at 20°C
Yield point
Rp0,2
N / mm²
≥ 1030
Tensile strength
Rm
N / mm²
≥ 1280
Elongation
A5,65
≥ 12%
Modulus of elasticity
kN / mm²
204
Weldability
The material 2.4668 can be welded well using many different welding processes. The pulsed technique should be used for gas-shielded arc welding. The workpiece should be welded in a stress-free, metallically bright and dirt-free condition and Alloy 718 should be in a solution-annealed condition. Low heat input, targeted heat conduction and rapid heat dissipation are recommended. The line bead technique should be used. The interpass temperature should not exceed 100°C. Annealing colours should be removed directly after welding, i.e. while still warm, using a stainless steel brush.
Machinability
Alloy 718 is easier to machine in the solution-annealed condition, whereas better results in terms of surface quality can be achieved in the hardened condition. The material 2.4668 tends to work harden more than low-alloy austenites. For this reason, a low cutting speed and a low feed rate should be selected. The tool should be in constant engagement. A sufficient cutting depth should be selected so that the previously created work-hardened zone can be undercut. To ensure a stable cutting process, heat dissipation should be optimised by using large quantities of suitable, water-based cooling lubricants.
Cold forming
Cold forming should be carried out in the solution-annealed condition. The material 2.4668 has a significantly higher work hardening rate than most austenitic stainless steels.
Thermal treatment
| Solution annealing | |
|---|---|
| Hardening | 620 - 790°C (cooling: air) |
| Solution annealing | |
|---|---|
| Hardening | 620 - 790°C (cooling: air) |
Physical properties
Density
at 20°C
kg/dm³
8,26
Electrical
Resistance at 20°C
(ohm) mm²/m
1,18
Melting range
1257 - 1342°C
Thermal conductivity
at 20°C
W/m K
11,5
Specific
Heat capacity
at 20°C
J/kg K
460
Markets & Applications
Chemistry
Oil and Gas
Aerospace
Gas turbines
Environmental technology
Our
Delivery programme
Frequently asked questions
Important note
TEAM EDELSTAHL operates purely as a trading company without technical staff. Consequently, we are not authorised to provide material consulting services.
The above values and information on the properties and/or usability of the material are purely informative. This information is based on the experience of the manufacturer and TEAM EDELSTAHL. All information is without guarantee. Misprints, errors and changes excepted.
