Incoloy 825 Vs Inconel 625
Inconel is a nickel based superalloy. According to the amount of nickel present in the alloy and by considering many other parameters, we can grade Inconel differently. And the two such grades are Inconel 625 and Incoloy 825. The main difference between the two is that Inconel 625 contains a high amount of nickel as compared to Incoloy 825.
What is Inconel 625?
Inconel 625 contains a high amount of nickel than other grades of Inconel, and it is nickel-based superalloy. At higher temperature it has high strength and great resistivity. Against corrosion and oxidation it shows great protection. In nuclear and marine applications these specific advantages make it very useful.
Inconel 625 alloy service temperature ranges from cryogenic to 982°C. The alloy high strength is due to the stiffening effect of niobium and molybdenum, which locates in the nickel-chromium matrix. Therefore Inconel alloy does not need precipitation hardening treatments. Inconel 625 is an excellent choice for seawater applications due to high tensile strength, high corrosion-fatigue strength and resistance to chloride-ion stress-corrosion cracking. Apart from this, it exhibits excellent toughness and ductility at low temperature.
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 % |
What is Incoloy 825?
When compared to other Inconel grades, Incoloy 825 contains a moderate amount of nickel and is a nickel based superalloy. It consist a higher melting point but has low yield strength and a low tensile strength. And it contains chromium and nickel along with titanium, molybdenum and copper. It specifically provides an exceptional corrosion resistance to aqueous corrosion. Beside this, it exhibits oxidizing resistance and reducing acids such as phosphoric and sulfuric acids.
Difference between Inconel 625 and Incoloy 825
| Inconel 625 | Incoloy 825 | |
| Defination | It is nickel based superalloy which contains a high amount of nickel than any other grade of Inconel | It is nickel based superalloy which contains a moderate amount of nickel as compared to any other grade of Inconel |
| Nickel Content | It contains about 58% of nickel | It contains about 36-48% of nickel |
| Tensile Strength | It has very high tensile strength and yield strength | It has comparatively low tensile strength and yield strength |
| Elongation | It’s elongation is about 42.52% | It’s elongation is about 30% |
Incoloy 825 Material Composition
| Alloy | Ni | Cr | Fe | Mb | Ti | Cu | Mn | C | S | Al | Si |
| Incoloy 825 | 38.0 – 46.0 | 19.5 – 23.5 | 22.0 min | 2.5 – 3.5 | 0.6 – 1.2 | 1.5 – 3.0 | 1.0 max | 0.05 max | 0.03 max | 0.2 max | 0.5 max |
Alloy 825 Equivalent Material
| ALLOY | WERKSTOFF NR. | UNS | GOST | AFNOR | JIS | BS | EN | OR |
| Incoloy 825 | 2.4858 | N08825 | ЭП703 | NFE30C20DUM | NCF 825 | NA 16 | NiCr21Mo | XH38BT |
Alloy 825 Mechanical Properties, Density, Melting Point, and Tensile Strength
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| 8.14 g/cm3 | 1400 °C (2550 °F) | Psi – 80,000 , MPa – 550 | Psi – 32,000 , MPa – 220 | 30 % |
