What is the difference between Inconel 625 and 825?
Incoloy 825 and Inconel 625
Inconel is a nickel-based high-temperature alloy. Inconel alloys can be graded differently depending on the amount of nickel in the alloy and taking into account many other parameters. The two grades are Inconel 625 and Incoloy 825. The main difference between the two is that Inconel 625 contains a higher amount of nickel compared to Incoloy 825.
What is Inconel 625?
Inconel 625 has a higher nickel content than other Inconel grades and is a nickel-based superalloy. High strength and large resistivity at higher temperatures. It has a strong protective effect against corrosion and oxidation. These specific advantages make it very useful in nuclear and marine applications.
Inconel 625 alloy has an operating temperature range from cryogenic to 982°C. The alloy's high strength is due to the hardening effect of niobium and molybdenum located in the nickel-chromium matrix. Inconel therefore does not require precipitation hardening. Inconel 625 offers high tensile strength, high corrosion fatigue strength and resistance to chloride ion stress corrosion cracking, making it an excellent choice for seawater applications. In addition to this, it exhibits excellent toughness and ductility at low temperatures.
Inconel Alloy 625 Chemical Composition
| Inconel | Element (% by mass) | ||||||||||||||
| Ni | Cr | Fe | Mo | Nb | Co | Mn | Cu | Al | Ti | Si | C | S | P | B | |
| 625 | 58.0 | 20.0–23.0 | 5.0 | 8.0–10.0 | 3.15–4.15 | 1.0 | 0.5 | 0.4 | 0.4 | 0.5 | 0.1 | 0.015 | 0.015 | ||
Alloy 625 Equivalent Material
| STANDARD | WERKSTOFF NR. | UNS | GOST | AFNOR | JIS | BS | EN | OR |
| Inconel 625 | 2.4856 | N06625 | ХН75МБТЮ | NC22DNB4M | NCF 625 | NA 21 | NiCr22Mo9Nb | ЭИ602 |
Inconel 625 Mechanical Properties
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation | |
| 625 | 8.4 g/cm3 | 1350 °C (2460 °F) | Psi – 135,000 , MPa – 930 | Psi – 75,000 , MPa – 517 | 42.5 % |
