Incoloy 825, Alloy 825, 2.4858, N08825

Grade	Code	UNS	Nickel Alloys
Incoloy 825	Alloy 825 (2.4858)	N08825	Nickel Alloys

Nickel Alloy Properties

Incoloy 825 / Alloy 825, is a nickel-iron-chromium alloy with additions of molybdenum, copper and titanium, developed to provide high resistance to both oxidizing and reducing corrosive environments. It shows good corrosion resistance in reducing acids such as sulfuric and phosphoric acid, in oxidizing media containing nitric acid and nitrates, in organic acids, alkaline solutions and acidic chloride solutions. Its high nickel content helps resist chloride stress-corrosion cracking, while the molybdenum and copper additions improve performance against pitting, crevice corrosion and reducing acid environments.

Chemical Analysis (Incoloy 825 / Alloy 825)

Ni %	Cr %	C %	Mo %	Mn %	Si %	Al %	Ti %	Cu %	Fe %
38.00 – 46.00	19.50 – 23.50	0.05 max.	2.50 – 3.50	1.00 max.	0.50 max.	0.20 max.	0.60 – 1.20	1.50 – 3.00	Balance

Mechanical Properties

Product form	Condition	Rp0.2, MPa	Rm, MPa	Elongation, %	Hardness, HB	Density, g/cm³
Round bar / Rod & Bar	Solution annealed — ASTM B425 type	≥ 241	≥ 586	≥ 30	135–165 typ.	8.14
Plate / Sheet / Strip	Solution annealed — ASTM B424 type	≥ 241	≥ 586	≥ 30	135–165 typ.	8.14
Seamless pipe / tube	Hot-finished solution annealed — ASTM B423	≥ 172	≥ 517	≥ 30	135–165 typ.	8.14
Seamless pipe / tube	Cold-worked solution annealed — ASTM B423	≥ 241	≥ 586	≥ 30	135–165 typ.	8.14

Application Areas

Industry / Application Area	Most Common Products	Brief Description
Oil, Gas and Offshore Platforms	Pipe, tubing, fittings	Preferred for lines exposed to chlorides, acidic media and seawater due to its corrosion resistance.
Chemical Production Plants	Reactors, tanks, piping systems	Used in demanding chemical environments containing sulfuric, phosphoric and organic acids.
Acid Baths and Surface Cleaning Plants	Heating coils, acid tanks, handling equipment	Provides a long service life in metal surface cleaning and acid bath applications.
Fertilizer and Phosphoric Acid Production	Heat exchangers, evaporators, washing equipment	Used in these production lines because it resists acidic and chloride-containing environments.
Flue Gas and Waste Gas Treatment Systems	Scrubber components, waste heat exchangers, chemical waste lines	Preferred in systems exposed to acidic gases, condensate and corrosive waste liquids.
Nuclear and Radioactive Waste Processing	Fuel processing equipment, waste transfer lines, process tanks	Used in special process equipment where high corrosion resistance is required.
Marine and Seawater Applications	Seawater piping, shaft components, exhaust systems	Performs well against corrosion in seawater and saline environments.

Description

Incoloy 825 / Alloy 825, provides advantages not only through corrosion resistance, but also through its suitability for fabrication and manufacturing processes. It can be welded using conventional welding methods and is suitable for both hot and cold forming. However, work hardening should be considered during heavy deformation, and intermediate annealing may be required when necessary. These properties make it a practical choice for pipes, tanks, heat exchangers and special process equipment, offering both ease of fabrication and long service life.

Specification

Incoloy 825, Alloy 825, 2.4858, N08825

Standards

Product Form	ASTM / ASME	Description
Solid Bar	ASTM B425 / ASME SB425	Covers hot-finished or cold-drawn round, square, hexagonal and rectangular bars.
Plate	ASTM B424 / ASME SB424	Covers rolled plate, sheet and strip products.
Seamless Pipe	ASTM B423 / ASME SB423	Covers cold-worked or hot-finished seamless pipe and tube for general corrosive service.
Welded Pipe	ASTM B705 / ASME SB705	Covers annealed UNS N08825 welded pipe.
Welded Tube	ASTM B704 / ASME SB704	Generally considered for welded tube and heat-exchanger type products rather than pipe.