ALLOY 625
NICKEL & SUPER ALLOYS
UNS N06625: ASTM B446 & B564
GENERAL SCOPE
Alloy 625 is a Nickel – Chromium alloy with additions of Niobium (Columbium) and Molybdenum.
It has good stress-rupture strength up to 980°C (1800°F), resists oxidation and exhibits good resistance against chloride-ion stress corrosion cracking and crevice corrosion. It also has excellent fatigue strength and cryogenic properties.
It has widely used applications in marine and chemical processing environments, in forms such as seals, fasteners, heat exchangers, valves, steam lines, exhaust ducts, etc. It is also used as a weld overlay for corrosion resistance purposes.
CHEMICAL COMPOSITION
| C | Si | Mn | P | S | Cr | Ni | Mo | NbCbTa | Ti | AI | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min | . | . | . | . | . | 20.00 | 58.00 | 8.00 | 3.15 | . | . | 0.00 |
| Max | 0.10 | 0.50 | 0.50 | 0.015 | 0.015 | 23.00 | . | 10.00 | 4.15 | 0.40 | 0.40 | 5.00 |
MECHANICAL PROPERTIES
Condition: Annealed
| U.T.S | 120 KSI Min | (827 N/mm2) |
| 0.2% Proof Stress | 60 KSI Min | (414 N/mm2) |
| Elongation | 20 % | |
| Red of Area | 35 % | |
| CVN Impacts @ -40°C (-40°F) | 27 Joules | (20 ft-lbf) |
NACE MR0175 limits the supply hardness to 35 HRC max.