About FV520B
FV520B is a martensitic precipitation hardening stainless steel. Its nominal analysis is about 14% Cr, 5% Ni, 1.5% Mo and 1.5% Cu, with a small amount of Nb. It gets its strength from copper-rich particles that form during ageing, and it has good anti-galling properties.
FV520B is often compared with 17-4PH, and in some environments it resists corrosion better. Depending on heat treatment, the 0.2% proof strength is 720 MPa to 1030 MPa minimum, and impact energy stays at 40 J or more down to -70°C. FV520B can be welded with matching filler metal. It is widely used for centrifugal compressor impellers working in corrosive gas.
Equivalent Grades
| Standard | Designation |
|---|---|
| Trade name | FV520B |
| EN material number | 1.4594 |
| EN steel name | X5CrNiMoCuNb14-5 |
| UNS (close equivalent) | S45000 |
| British aerospace | S143 / S144 / S145 |
Chemical ranges vary slightly between EN, ASTM and aerospace standards. Please tell us which standard you need.
Chemical Composition (wt %)
| Element | Content | Element | Content |
|---|---|---|---|
| Carbon (C) | 0.07 max | Chromium (Cr) | 13.20 - 14.70 |
| Manganese (Mn) | 1.00 max | Nickel (Ni) | 5.00 - 6.00 |
| Silicon (Si) | 0.70 max | Molybdenum (Mo) | 1.20 - 2.00 |
| Phosphorus (P) | 0.035 max | Niobium (Nb) | 0.20 - 0.70 |
| Sulphur (S) | 0.025 max | Copper (Cu) | 1.20 - 2.00 |
Mechanical Properties
| Condition | 0.2% Proof Stress (N/mm²) | Tensile Strength (N/mm²) | Elongation (% min) | Hardness (HB) | Izod (J min) |
|---|---|---|---|---|---|
| Primary Hardened 1050°C + 2 h 750-850°C AC | - | - | - | 293 - 341 | - |
| Double Overaged 1050°C + 2 h 750-850°C AC + 2 h 750-850°C AC | 800 | 925 - 1090 | 15 | 277 - 341 | 54 |
Typical values for rolled bar, longitudinal. Properties of each forging depend on section size and heat treatment and are agreed with the customer.
FV520B Forged Products
Applications
FV520B is used where a part needs high strength and corrosion resistance at the same time: centrifugal compressor impellers, pump shafts and impellers, turbine blades, valves and valve stems, fasteners, fans, hydraulic parts, aerospace parts and nuclear transport flasks. Our FV520B forgings go to the petrochemical, oil and gas, offshore, marine, power and nuclear industries.
Production and Inspection
| Melting | EAF + VOD + ESR |
|---|---|
| Forging | Open-die forging and ring rolling |
| Ultrasonic test | EN 10228-3, SEP 1921, ASTM A388 or customer specification |
| Certificate | EN 10204 3.1, or EN 10204 3.2 with third party inspection |
| Supply | To customer size or drawing |
FAQ
What is FV520B?
A martensitic precipitation hardening stainless steel (about 14Cr-5Ni-1.5Mo-1.5Cu-Nb). It is hardened by copper-rich precipitates and has good anti-galling properties.
What are the equivalent grades of FV520B?
EN 1.4594 (X5CrNiMoCuNb14-5) and BS S143, S144, S145. UNS S45000 is a close equivalent.
What is the difference between FV520B and 17-4PH?
Both are martensitic PH stainless steels hardened by copper. FV520B also contains molybdenum and niobium, and in some environments it resists corrosion better than 17-4PH.
Can you make FV520B forgings to my drawing?
Yes. Jiangyin Jiangnan Metal Co., Ltd. makes FV520B forged rings, shafts, discs, bars and flanges to customer drawings at our forging plant in Jiangyin, Jiangsu, China.
What tests and certificates do you supply?
Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, with an EN 10204 3.1 certificate or a third party EN 10204 3.2 certificate.
How do I get a price?
Send the drawing or sizes, quantity and required standard to sales@steelforgepieces.com, or call 0086-189-2135-9659.
References
British Stainless Steel Association: FV520B / 1.4594
Nie D. et al. (2020): Stress corrosion cracking behaviors of FV520B stainless steel, Engineering Failure Analysis