GH825
GH825 is a titanium stabilized fully austenitic nickel-iron-chromium alloy with copper and molybdenum added. GH825 is a general engineering alloy that is resistant to acid and alkali metal corrosion in both oxidizing and reducing environments.
The high nickel content makes the alloy effectively resistant to stress corrosion cracking. It has good corrosion resistance in various media, such as sulfuric acid, phosphoric acid, nitric acid and organic acids, alkali metals such as sodium hydroxide, potassium hydroxide and hydrochloric acid solutions. The high comprehensive performance of GH825 is reflected in the nuclear combustion dissolver with a variety of corrosive media, such as sulfuric acid, nitric acid and sodium hydroxide are all processed in the same equipment.
GH825 alloy has good overall corrosion resistance to both oxidizing and non-oxidizing acids due to its rich content of Cr, Mo and Cu. It has extremely high corrosion resistance to sulfuric acid. Due to the high content of Cr, Mo and Ni, it has excellent resistance to pitting corrosion, crevice corrosion and stress corrosion cracking in chloride environments.
825 alloy controls the carbon content at an extremely low level, is not easily sensitized during welding, and has low intergranular corrosion sensitivity.
Content
Chemical composition of GH825(%)
| Element | Minimum(%) | Maximum(%) |
|---|---|---|
| Ni | 38 | 46 |
| Cr | 19.5 | 23.5 |
| Fe | remiander | remiander |
| C | - | 0.025 |
| Mn | - | 1 |
| Si | - | 0.5 |
| Cu | 1.5 | 3 |
| Mo | 2.5 | 3.5 |
| Al | - | 0.2 |
| Ti | 0.6 | 1.2 |
| P | - | 0.02 |
| S | - | 0.01 |
Physical properties of GH825
| Property | Value |
|---|---|
| Density | 8.14 g/cm3 |
| Melting range | 1370-1400 ℃ |
Mechanical properties of GH825 alloy
| Property | Value |
|---|---|
| Tensile Strength | 550 MPa |
| Yield Strength | 220 MPa |
| Elongation | 30% |
| Hardness (HBS) | ≤200 |
Applications of GH825
GH825 alloy is widely used in various industrial fields with a service temperature not exceeding 550℃.
- Heating pipes, containers, baskets and chains used in sulfuric acid pickling plants,
- Seawater cooling heat exchangers, marine product pipeline systems, acid gas environment pipelines,
- Heat exchangers, evaporators, washing and immersion pipes in phosphoric acid production,
- Air heat exchangers in petroleum refining,
- Flame retardant alloys for high-pressure oxygen applications
