Inconel 625 belongs to the group of nickel-chromium alloys with the addition of niobium and molybdenum additives. Such a complex structural composition contributes to a significant increase in the strength of the alloy, without the need for its thermal strengthening.
The Russian analogue of Inconel 625 is KhN75MBTYu material in accordance with GOST 5632.

Products made of alloy 625 are capable of operating in wide temperature regimes - from minus to high, reaching 980 . In addition, Inconel Alloy 625 has unique resistance to corrosive environments, especially in direct contact with acids. It is characterized by high resistance to gas corrosion damage (at high temperatures). The alloy is easily weldable of any type.
Physical properties
Density of alloy Inconel 625 (weight) - 8.44 g / cm3
Thermal properties N06625

In accordance with the provisions of the ANSI / NACE MR0175 standard, Inconel 625 is regulated as type 4d - annealed and cold worked materials, based on nickel. And it is a hard alloy intended for use in a wide range of equipment, units and parts.
Due to its composition, Inconel 625 N06625 is in demand and indispensable in modern production of the oil and gas, chemical industry, aviation, shipbuilding, instrument making, and when creating parts of reactors in the nuclear industry.
An improved modification of Inconel 625 is Inconel alloy 625LCF N06626, the main unique characteristic of which is fatigue strength under the influence of cyclical temperature drops reaching 650 C.
Inconel 625 LCF is available in plates, fittings and tapes. Also rolled products from this alloy include Inconel 625 wire, Inconel 625 sheet, etc.
Corrosion resistance
Optimum corrosion resistance is only observed when the material is provided for use in a clean, metallic luster condition. Nicrofer® 6020 hMo exhibits extreme corrosion resistance against a wide range of media;
excellent resistance to pitting and crevice corrosion in chloride-containing environments;
excellent resistance to chloride-induced stress corrosion cracking;
high resistance to corrosion from mineral acids such as nitric, phosphoric, sulfuric and hydrochloric; also from high concentrations of alkalis and organic acids, as well as under oxidizing and reducing conditions;
very good resistance to sea and brackish water, also at elevated temperatures;
high resistance to intercrystalline corrosion after annealing and welding;
high resistance to erosion corrosion.
The high carbon version is resistant to many corrosive gas atmospheres. He has:
good resistance to carburization and scale formation under static and variable conditions, suitable for use in air up to 1000 C (1830 F);
resistance to nitriding;
good resistance to halogens and hydrogen chloride.
Nicrofer 6020 hMo can be welded using all conventional welding methods: non-consumable, consumable electrode, hot-electrode, plasma, active gas, submerged arc and arc welding.
The following welding materials are recommended:
Nicrofer S6020-FM 625
Op material. No. 2.4831
Short designation SG-NiCr21Mo9Nb
AWSA5.14 ERNiCrMo-3
Coated rod electrodes
Op.material. No. 2.4621
Short designation EL-NiCr20Mo9Nb
AWSA5.11: ENiCrMo-3
Nicrofer S / B 6020 / FM 625 / WS 625
Op.material No. 2.4831
AWSA6.14: ERNiCrMo-3
Main features and advantages of the alloy:
Extremely resistant to pitting, crevice, erosion and intergranular corrosion;
Insensitivity to chloride-induced tensile stress corrosion cracking;
Good resistance to mineral acids such as nitric, phosphoric, sulfuric and hydrochloric acids;
Good resistance to alkalis and organic acids;
Good mechanical properties.
Main areas of use:
installations for the production of superphosphoric acid;
installations for the enrichment of radioactive waste;
gas pipelines;
production pipe systems and risers for oil production;
coastal industry;
shipbuilding sea water pipelines;
expansion joints resistant against cracking corrosion;
wet flue gas cleaner;
flare pipes for burning in oil refineries;
expansion joints for hot exhaust gases;
boiler pipes in waste incineration plants;
hard facing by cladding in incinerators.
Various products are produced from this alloy according to ASTM standards:
B366 - fittings;
B443 - Plates, sheets, strips;
B444 - pipes;
B446 - rods;
B564 - forgings;
B704, B705 - welded pipes;
B751 - welded pipes;
B834 - pipe flanges, fittings, valves;
B924 - Seamless welded tubes for heat exchangers and condensers with integrated fins.

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