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Alloy 825 / Incoloy 825 / N08825 / 2.4858
An improved modification of the Incoloy 825 alloy, this material Incoloy 925 /
Inconol 925 is fully consistent with its chemical composition and properties.
The structural composition of Incoloy 825 / Inconel 825 is complex:
nickel-iron-chromium-molybdenum-copper-titanium. This material was created by
the Special Metals Corporation. The use of Incoloy 825 is considered to be the
most economical due to its excellent anti-corrosion properties. Its main
characteristic is its high resistance to corrosive formations in acidic
environments (of any concentration) and local corrosion - the most dangerous for
metals. Such corrosion provokes local damage to the grain, and leads to a loss
of strength and ductility.
The presence of different metals in its composition gives it unique properties,
and puts it in the category of "super alloys".
Nickel prevents stress corrosion cracking, that is, it determines a high level
of resistance to damage from ionic chloride destruction.
The composition of alloy 825 N08825 of nickel, molybdenum and copper gives
the alloy resistance to acidic conditions (phosphoric and sulfuric acids).
Molybdenum increases the resistance to local corrosion, prevents the formation
of corrosive formations in gaps and crevices (local crevice electrical
corrosion).
Chromium is responsible for imparting resistance to the alloy when used in
oxidizing environments (nitrate, nitric acid).
Titanium with special thermal deformation provides alloy 825 with resistance to
intergranular corrosion damage.
According to NACE MR0175 / ISO 15156 standard, Incoloy 825 / Inconel 825 is
regulated as type 4c - in cold deformed condition and after annealing.
On the basis of Alloy 825, the engineers of the concern have created improved
versions - Incoloy alloy 925 N09925 and Incoloy alloy 945 / 945X N09945.
The unique characteristics of the Incoloy 825 allow it to be used for the
manufacture of products capable of operating in difficult process and
temperature conditions.
They are in demand in the petrochemical industry, they are installed in oil and
gas pipelines, in heat exchangers, in units that produce gasoline and process
nuclear fuel.
Corrosion resistance
Nicrofer 4221 is a versatile construction material with resistance to acids and
alkalis as well as oxidizing and reducing corrosive conditions.
The high nickel content makes the alloy practically insensitive to stress
corrosion cracking.
Corrosion resistance in various media such as sulfuric, phosphoric, nitric and
organic acids is good, as well as in alkalis, as well as in ammonia, sea water
and salt solutions.
The versatility of Nicrofer 4221 is demonstrated by its use in solution tanks
for nuclear fuel cells, which use a large number of corrosive media, such as
sulfuric and nitric acid and caustic soda alternately.
Welding
Nicrofer 4221 can be welded using all conventional welding methods:
Non-consumable electrode welding;
Consumable electrode welding;
Electric welding;
Plasma.
The following welding material is recommended:
Non-consumable electrode welding
Nicrofer S6020® Order No. 2.4831
Consumable electrode welding
SG-NiCr21Mo9Nb
Rod electrodes
op. no. 2.4621
EL-NiCr20Mo9Nb.
Main features and advantages of the alloy:
Good resistance to stress corrosion cracking;
Satisfactory resistance to pitting and crevice corrosion;
Good resistance to oxidizing and non-oxidizing hot acids;
Good mechanical properties, both at room temperature and at elevated
temperatures up to approx. 550 กใ C (1020 กใ F);
Compressed gas cylinders approved up to 425 กใ C (843 กใ F).
Main areas of use:
components in sulfuric acid pickling plants such as heating coils, tanks,
boilers, chains;
solvent fuel cells for various media such as sulfuric and nitric acid, sodium
hydroxide solution, etc., which are used in the processing process;
seawater cooled heat exchangers, offshore pipelines, pipes and parts for natural
gas exploitation;
heat exchangers, evaporators, washers, plungers in the production of phosphoric
acid;
air-cooled heat exchangers in a liquefied gas (LPG) process;
food production;
chemical installations.
Various products are produced from this alloy according to ASTM standards:
B163 - seamless tubes for condensers and heat exchangers;
B366 - Forged fittings;
B423 - seamless pipes;
B424 - plates, sheets, strips;
B564 - forgings;
B704, B705 - welded pipes;
B924 - Seamless welded tubes for heat exchangers and condensers with integrated
fins.
Other materials
Steel X11CrMo5 + NT1 - 1.7362 + NT1
Steel FeNi20MCLP
Steel Ni6276
Steel X80MO - 1.8786
Steel G 4059 - 1.4059
FM 725NDUR / ERNiCrMo-15 / N07725
ASTM F844 / ASME SF844
ASTM A666 / ASME SA666
Inconel 625 / N06625 / 2.4856 Inconel 601 / N06601 / 2.4851 Inconel 718 / N07718 / 2.4668 Inconel 690 / N06690 / 2.4642
Inconel 617 / N06617 / 2.4663 Inconel X-750 / N07750 / 2.4669 Inconel 600 / N06600 / 2.4816 1.4876 / 1.4958:
Incoloy 800HT / N08811 / 1.4959 Incoloy 825 / N08825 / 2.4858 Incoloy 800H / N08810 / 1.4958 Incoloy 20 / N08020 / 2.4660
Incoloy 925 / UNS N09925 Hastelloy B-2 / N10665 / 2.4617 Hastelloy C-276 / N10276 / 2.4819 Hastelloy C-22 / N06022 / 2.4602
Hastelloy B-3 / UNS 10675 / 2.4600 Hastelloy C-4 / N06455 / 2.4610 Hastelloy X / N06002 / 2.4665 Monel 400 / UNS N04400 / 2.4360