2.4856
Data sheet material 2.4856 / Alloy 625
NiCr22Mo9Nb
Nickel-chromium-molybdenum-niobium alloy
Brief description
The material 2.4856 or Alloy 625 or Inconel® 625 is a nickel-chromium-molybdenum-niobium alloy with excellent properties in many corrosive media. A distinction is made between the soft-annealed condition (grade 1) and the solution-annealed condition (grade 2). Grade 1 is suitable for applications below 600°C, while grade 2 is suitable for high-temperature applications with operating temperatures above 600°C.
Standards and nomenclature
| EN | |
|---|---|
| DIN | NiCr22Mo9Nb |
| AISI | Alloy 625, Inconel® 625 |
| US | N06625 |
| EN | |
|---|---|
| DIN | NiCr22Mo9Nb |
| AISI | Alloy 625, Inconel® 625 |
| US | N06625 |
Chemical composition according to VdTÜV-WB 499
| Ni (nickel) | 58,0 | 71,0 |
| Cr (chromium) | 21,0 | 23,0 |
| Fe (iron) | - | 5,0 |
| C (carbon) | 0,03 | 0,1 |
| Mn (manganese) | - | 0,5 |
| Si (silicon) | - | 0,4 |
| Co (Cobalt) | - | 1,0 |
| Al (aluminium) | - | 0,4 |
| Ti (titanium) | - | 0,4 |
| P (phosphorus) | - | 0,01 |
| S (sulphur) | - | 0,01 |
| Mo (molybdenum) | 8,0 | 10,0 |
| Nb + Ta (niobium + tantalum) | 3,2 | 3,8 |
-
-
min.
max.
Ni
(nickel)
58,0
71,0
Cr
(chrome)
21,0
23,0
Fe
(iron)
-
5,0
C
(carbon)
0,03
0,1
Mn
(Manganese)
-
0,5
Si
(Silicon)
-
0,4
Co
(Cobalt)
-
1,0
-
-
min.
max.
Al
(aluminium)
-
0,4
Ti
(Titanium)
-
0,4
P
(phosphorus)
-
0,01
S
(sulphur)
-
0,01
Mo
(Molybdenum)
8,0
10,0
Nb + Ta
(niobium + tantalum)
3,2
3,8
-
-
-
-
General properties
| Corrosion resistance | |
|---|---|
| Mechanical properties | good |
| Weldability | good |
Special properties
Soft annealed condition (grade 1):
Suitable for wet corrosion applications with operating temperatures below 600°C.
Solution annealed condition (grade 2):
Suitable for high-temperature applications above 600°C, the maximum operating temperature is approx. 1050°C.
Corrosion resistance
Optimum corrosion resistance is achieved in a clean, bare metal condition. Alloy 625 is resistant to seawater.
The following corrosion resistance properties apply to the material 2.4856 in the soft annealed condition (grade 1):
- Excellent resistance to pitting and crevice corrosion in chlorinated environments
- Insensitivity to chloride-induced stress corrosion cracking
- High resistance to intergranular corrosion and erosion corrosion
- High resistance to mineral acids (nitric, phosphoric, sulphuric and hydrochloric acid) and organic acids as well as alkalis
- Very good resistance even at higher temperatures in seawater and brackish water
In the solution-annealed condition (grade 2), Alloy 625 has very good properties in corrosive gas atmospheres:
- Good resistance to carburisation and oxidation (application temperature up to 1050°C possible)
- Good resistance to halogenated gases and hydrogen chloride
Mechanical properties
at 20°C
Hardness
HB
≤ 240
Yield point
Rp0,2
N / mm²
≥ 415
Tensile strength
Rm
N / mm²
820 - 1050
Elongation
A5,65
≥ 30%
Modulus of elasticity
kN / mm²
209
Weldability
The material 2.4856 can be welded using all standard welding processes (TIG, TIG hot wire, plasma, MIG/MAG and MAG tandem, submerged arc and manual metal arc welding). The workpiece should be in a stress-free, metallically bright and dirt-free condition. A low heat input is recommended. Annealing colours should be removed directly after welding, i.e. while still warm, using a stainless steel brush. Heat treatment before and after welding is generally not necessary.
Machinability
Machining should be carried out in the annealed condition. Alloy 625 tends to work harden. Therefore, 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.
Cold forming
Cold forming should be carried out in the annealed condition. The material 2.4856 has a significantly higher work hardening rate than most austenitic stainless steels. Intermediate annealing should be carried out for severe cold forming. If the degree of deformation exceeds 15%, a final soft annealing (grade 1) or solution annealing (grade 2) should be carried out.
Thermal treatment
| Soft annealing (grade 1) | |
|---|---|
| Solution annealing (grade 2) | 1080 - 1160°C |
| Low-voltage annealing | 600 - 810°C |
| Hot forming | 1150 - 900°C |
| Cooling down | Fast with water; rapid air cooling for thicknesses under 3 mm |
| Soft annealing (grade 1) | |
|---|---|
| Solution annealing (grade 2) | 1200 - 900°C |
| Low-voltage annealing | 600 - 810°C |
| Hot forming | 1150 - 900°C |
| Cooling down | Fast with water; rapid air cooling for thicknesses under 3 mm |
Physical properties
Density
at 20°C
kg/dm³
8,47
Electrical
Resistance at 20°C
(ohm) mm²/m
1,28
Melting range
1290 - 1350°C
Thermal conductivity
at 20°C
W/m K
9,8
Specific
Heat capacity
at 20°C
J/kg K
415
Markets & Applications
Chemistry
Oil and Gas
Offshore
Compensators / recuperators
Nuclear technology
Shipbuilding
Flue gas desulphurisation systems
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.
