Fenicro®31 is Fe-Ni-Cr-Mo alloy with nitric additive.
The developed alloy fills a niche between the high-alloyed austenitic stainless steels and nickel alloys.
Fenicro®31 ideally conforms to requirements for application in the chemical and petrochemical industry, cleaning constructions and also at oil and gas production.
It is characterized by:
- excellent anticorrosive resistance in halogen environments, as well as in acid;
- excellent resistance to sulfuric acid, even high-concentrated;
- resistance to corrosion and erosive corrosion in the phosphorus acid environments;
- special resistance to the general and local corrosion in the lixivating environment of dioxide of chlorine;
- good workability and weldability;
- it is resolved for the joints of high pressure which are operated at a temperature from -196°С to 550°С (-320 to 1020°F).
- it is allowed by ISO 15 156/MR according to the test of level VI for use of high-sulphurous gases in gas supply
Hot processing by pressure.
Fenicro®31 is necessary to subject to hot processing by pressure in the field of temperatures between 1200 and 1050oС (2190-1920°F) with the subsequent hardening in water or accelerated cooling by air. Heat treatment after hot processing by pressure is recommended for achievement of optimum characteristics and the maximum corrosion properties.
For heating the processed products place in the furnace which is already warmed up to the maximum working temperature (homogenization). After the furnace reaches the temperature again, material has to be kept about 60 minutes on 100 mm of thickness.
Upon termination of the period of endurance products have to be immediately unloaded and processed in the top temperature range. After metal temperature drop below 1080oС (1980°F) repeated heating is required.
Cold processing by presure
Fenicro® 31 has higher peening than austenitic stainless steels. At the choice of devices for processing by pressure it is necessary to consider it, and the processed product has to be after diffusive annealing. At strong draftings intermediate annealings are necessary.
When draftings over 15% it is necessary to carry out repeated diffusive annealing.
Country |
Standard |
Material description |
Germany |
SEW VdTÜV-Wbl BAM |
W.-Nr.1.4562 X1NiCrMoCu32-28-7 Material is pointed in BAM list for transport with danger cargo |
USA |
ASTM ASME |
UNS N08031 |
ISO |
Material is pointed in ISO 15 156/MR0175 |
The main importance is that the processed products before and during heat treatment remained clean and free from any impurity. Sulfur, phosphorus, lead and other fusible metals can lead Fenicro® 31 at heat treatment to embrittlement. Such impurity contain also in paints of marking and the indication of temperature or pencils and also in lubricants, oils, fuel, etc.
Fuel has to have whenever possible low content of sulfur. Natural gas has to contain less than 0,1% on the mass of sulfur. Liquid fuel with the content of at most 0,5% on weight can be used.
The atmosphere of the furnace has to be neutral to slightly oxidizing and shouldn't change between oxidizing and recovery. The processed products shouldn't be affected by fire directly.
Optimum corrosion resistance is provided only in case of pure material with the relevant metallurgical structure. The chemical composition of Fenicro®31 is selected so that corrosion properties were maximum in the halogenic environments. At the same time material shows excellent stability in the pure and polluted sulfuric acid of high concentration and at a temperature to 80°С (176°F). In the conditions of stronger erosive corrosion by production of phosphoric acid Fenicro®31 proves that really is an alternative to nickel alloys. Tests in the lixivating environment of dioxide of chlorine in installations of the paper and cellulose industry have shown that Fenicro®31 maintains more severe working conditions.
|
Ni |
Cr |
Fe |
C |
Mn |
Si |
Cu |
Mo |
N |
P |
S |
Min |
30.0 |
26.0 |
rest |
|
|
|
1.0 |
6.0 |
0.15 |
|
|
Max |
32.0 |
28.0 |
0.015 |
2.0 |
0.3 |
1.4 |
7.0 |
0.25 |
0.02 |
0.01 |
Yield strength |
Yield strength |
Tensile strength |
Elongation |
Hardness |
|||
σ0,2 N/mm2 |
ksi |
σ1,0 N/mm2 |
ksi |
σв N/mm2 |
ksi |
δ5, % |
НВ |
≥276 |
≥40 |
≥310 |
≥45 |
≥650 |
≥94 |
≥40 |
max 220 |