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.
Nicrofer 4221 can be welded using all conventional welding methods:
Non-consumable electrode welding;
Consumable electrode welding;
Electric welding;
The following welding material is recommended:
Non-consumable electrode welding
Nicrofer S6020® Order No. 2.4831
Consumable electrode welding
Rod electrodes
op. no. 2.4621
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

 Monel K-500 / N05500 / 2.4375      Monel R-405 / N04405