What is the Difference Between Alloy 925 and 718?

Date:2025-03-17 17:42:26View:80Tags:Nickel Alloy Supplier

When selecting materials for high-performance applications, Alloy 925 and Alloy 718 are two commonly considered nickel-based alloys. While both offer excellent strength, corrosion resistance, and durability, they are designed for different applications and have distinct chemical compositions, mechanical properties, and uses. This article explores the key differences between these two alloys.

1. Chemical Composition

Element	Alloy 925 (Incoloy 925)	Alloy 718 (Inconel 718)
Nickel (Ni)	42-46%	50-55%
Iron (Fe)	Balance	Balance
Chromium (Cr)	19.5-23.5%	17-21%
Molybdenum (Mo)	2.5-3.5%	2.8-3.3%
Copper (Cu)	1.5-3.0%	-
Titanium (Ti)	1.9-2.4%	0.65-1.15%
Aluminum (Al)	0.1-0.5%	0.2-0.8%
Niobium (Nb)	-	4.75-5.5%

2. Mechanical Properties

Property	Alloy 925	Alloy 718
Yield Strength	≥1034 MPa (150 ksi)	1034-1241 MPa (150-180 ksi)
Tensile Strength	≥1276 MPa (185 ksi)	1241-1480 MPa (180-215 ksi)
Hardness	Rockwell C30-40	Rockwell C35-45
Creep Resistance	Moderate	Excellent (up to 700°C)

3. Corrosion Resistance

Factor	Alloy 925	Alloy 718
Sulfide Stress Cracking Resistance	Excellent	Moderate
Chloride Pitting Resistance	High	Moderate
Oxidation Resistance	Moderate	Excellent (High Temperatures)

4. Applications

Industry	Alloy 925	Alloy 718
Oil & Gas	✓ (tubing, valves, downhole equipment)	✗
Marine	✓ (seawater-resistant components)	✗
Chemical Processing	✓	✗
Aerospace	✗	✓ (jet engines, turbine blades)
Nuclear Reactors	✗	✓
High-Temperature Fasteners & Springs	✗	✓

Conclusion

Alloy 925 and Alloy 718 are both nickel-based alloys with distinct strengths:

Alloy 925 excels in corrosive environments such as oil, gas, and marine applications.
Alloy 718 is designed for high-temperature and high-strength applications, making it ideal for aerospace and power generation.

Understanding their differences helps in selecting the right material for specific industrial needs.