2.4858
Data sheet material 2.4858 / Alloy 825
NiCr21Mo
Fully austenitic titanium-stabilised nickel-iron-chromium alloy
Brief description
The material 2.4858 or Alloy 825 or Incoloy® 825 is a titanium-stabilised, fully austenitic nickel-iron-chromium alloy with additions of copper and molybdenum with excellent resistance to a wide range of corrosive media. This material is resistant to corrosion in acids and alkalis as well as in oxidising and reducing environments.
Standards and nomenclature
| EN | |
|---|---|
| DIN | NiCr21Mo |
| AISI | Alloy 825, Incoloy® 825 |
| US | N08825 |
| EN | |
|---|---|
| DIN | NiCr21Mo |
| AISI | Alloy 825, Incoloy® 825 |
| US | N08825 |
Chemical composition according to DIN 17744
| Ni (nickel) | 38,0 | 46,0 |
| Cr (chromium) | 19,5 | 23,5 |
| Fe (iron) | 20,0 | 38,0 |
| C (carbon) | - | 0,025 |
| Mn (manganese) | - | 1,0 |
| Si (silicon) | - | 0,5 |
| Co (Cobalt) | - | 1,0 |
| Al (aluminium) | - | 0,2 |
| Ti (titanium) | 0,6 | 1,2 |
| P (phosphorus) | - | 0,02 |
| S (sulphur) | - | 0,015 |
| Mo (molybdenum) | 2,5 | 3,5 |
| Cu (copper) | 1,5 | 3,0 |
-
-
min.
max.
Ni
(nickel)
38,0
46,0
Cr
(chrome)
19,5
23,5
Fe
(iron)
20,0
38,0
C
(carbon)
-
0,025
Mn
(Manganese)
-
1,0
Si
(Silicon)
-
0,5
Co
(Cobalt)
-
1,0
-
-
min.
max.
Al
(aluminium)
-
0,2
Ti
(Titanium)
0,6
1,2
P
(phosphorus)
-
0,02
S
(sulphur)
-
0,015
Mo
(Molybdenum)
2,5
3,5
Cu
(copper)
1,5
3,0
-
-
-
-
General properties
| Corrosion resistance | |
|---|---|
| Mechanical properties | good |
| Weldability | good |
Special properties
Good toughness at continuous temperatures up to approx. 550°C
Corrosion resistance
Due to its high nickel content, the material 2.4858 is practically insensitive to stress corrosion cracking. It is also resistant to chloride-induced pitting and crevice corrosion. Alloy 825 also has good resistance to mineral acids (nitric, phosphoric, sulphuric and hydrochloric acid), organic acids, alkalis, ammonia and chloride alkalis. Its versatility is due to the fact that Alloy 825 is used in dissolution tanks for nuclear fuel elements, in which a variety of corrosive media act alternately. This material is resistant to seawater.
Mechanical properties
at 20°C
Yield point
Rp0,2
N / mm²
≥ 220
Tensile strength
Rm
N / mm²
≥ 550
Elongation
A5,65
≥ 30%
Weldability
The material 2.4858 can be welded using standard welding processes (TIG, MIG/MAG, plasma, electron beam welding and manual metal arc welding). The workpiece should be free of dirt and scale. The heat input should be kept low and the line bead technique should be used. Annealing colours should be removed immediately after welding, i.e. while still warm, using a stainless steel brush.
Machinability
Machining should be carried out in the annealed condition. Alloy 825 tends to work harden. Therefore, a low feed rate and a low cutting speed should be selected. In order to undercut the previously created work-hardened zone, the tool should be in constant engagement with a sufficient cutting depth.
Processing
| Cold forming | |
|---|---|
| Chip-removing processing | Yes |
| Cold forming | |
|---|---|
| Chip-removing processing | Yes |
Thermal treatment
| Soft or stable annealing | |
|---|---|
| Hot forming | 1150 - 900°C |
| Cooling down | Fast in water; rapid air cooling for thicknesses under 3 mm |
| Soft or stable annealing | |
|---|---|
| Hot forming | 1150 - 900°C |
| Cooling down | Fast in water; rapid air cooling for thicknesses under 3 mm |
Physical properties
Density
at 20°C
kg/dm³
8,05
Electrical
Resistance at 20°C
(ohm) mm²/m
1,12
Melting range
1370 - 1400°C
Thermal conductivity
at 20°C
W/m K
10,8
Specific
Heat capacity
at 20°C
J/kg K
440
Markets & Applications
Plant engineering
Chemistry
Oil and Gas
Offshore
Compensators / recuperators
Nuclear technology
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.
