Alloy 825: An Excellent Choice for High Performance Nickel Alloys- Shanghai Toko Technology Co.,Ltd

Alloy 825: An Excellent Choice for High Performance Nickel Alloys

Update:2025 18,Mar

Alloy 825 is a nickel-iron-chromium alloy with elements of molybdenum, copper and titanium, developed by Special Metals Corporation. It has very high corrosion resistance to both oxidizing and non-oxidizing acids.With its excellent corrosion resistance, high temperature strength and oxidation resistance, Alloy 825 is used in a wide range of applications such as petrochemical, offshore and nuclear energy.

International and Domestic Designations

Alloy 825 is standardized under various global specifications:

l Europe: NiCr21Mo, Z8NCuT25-20M

l Japan: JIS NW825

l Russia: ХН38ВТ (KHN38VT)

l China: NS142 or GH142

l Common name: Alloy 825, Inconel 825

The chemical composition of Alloy 825:

Alloy	%	Ni	Cr	Fe	C	Mn	Si	Cu	Mo	AI	Ti	Co	S
825	≥	38	19.5	Balance	-	-	-	1.5	2.5	-	0.6	-	-
825	≤	46	23.5	Balance	0.05	1	0.5	3	3.5	0.2	1.2	1	0.03

Physical Properties of Alloy 825 Mechanical Properties:

Alloy 825 Physical Properties:

Density	8.14g/cm³
Melting point	1370-1400℃
Coefficient of thermal expansion (CTE)	14.0 μm/m·℃ (20-100℃)
Thermal Conductivity	11.1 W/m·K (100℃)

Alloy 825 Minimum values of mechanical properties of the alloy at room temperature:

state	Tensile strength Rm N/mm²	Yield strength RP0.2 N/mm²	Elongation A5 %	Brinell hardness HB
Solid solution	550	220	30	≤220

Properties of Alloy 825:

1. Excellent corrosion resistance : Excellent performance in acidic, alkaline and chloride environments, especially suitable for sulfuric acid, phosphoric acid, nitric acid and seawater and other corrosive media.

2. Good high-temperature resistance : In high-temperature environments can still maintain high strength and stability, suitable for heat exchangers and high-temperature piping.

3. Excellent mechanical properties : High strength and good toughness, able to withstand high pressure and high load conditions.

4. Easy to process and weld : Suitable for a variety of processing and welding processes, to meet the design needs of complex projects.

Main application areas of Alloy 825

1. Oil and gas industry : Used in oil well casing, transmission pipelines and submarine pipelines, capable of resisting the erosion of corrosive media such as hydrogen sulfide and carbon dioxide.

2. Chemical industry : Used in the manufacture of reactors, heat exchangers and storage tanks, suitable for strong acid, strong alkali and other corrosive environments.

3. Marine engineering : Used in desalination equipment, marine platforms and ship pipelines, resisting seawater corrosion and biological attachment.

4. Nuclear energy industry : Used in the cooling system of nuclear reactor and high temperature pipeline, able to operate stably in the radiation environment.

5. Environmental protection and energy industry : Used in flue gas desulfurization (FGD) systems and waste treatment equipment, resisting corrosion of acidic media.

Processing and Welding of Alloy 825

Processing: Can be molded by hot and cold working, but need to pay attention to work hardening.

Welding: Suitable for a variety of welding methods, such as TIG, MIG, and manual arc welding, and heat treatment is usually not required after welding.

Summary

With its excellent corrosion resistance and mechanical properties, Alloy 825 is an ideal material for harsh environments and is used in a wide range of industrial applications.