6Mo / 1.4529
The austenitic stainless steel 6Mo was developed on basis of Alloy 904l / 1.4539. However, the molybdenum content at 6Mo was raised to 6.5%. 6Mo has excellent general corrosion resistance and improved resistance to pitting and crevice corrosion. The resistance to stress corrosion cracking is also increased. It is often referred as super austenitic stainless steel.
Characteristics
1.4529 is characterized by:
increased resistance to stress corrosion cracking compared to other austenitic stainless steels
excellent general corrosion resistance in use of oxidizing as well as reducing media
less tendency to form intermetallic phases compared to similar steels with only 18% nickel content
very good resistance at pitting and crevice corrosion
Approval for pressure vessels with temperatures between -196 and 400 ° C
Building construction approval for components and fasteners made of stainless steel, German Institute of Structural Engineering, September ’98
The material Alloy 6XN (UNS N08367) was developed in the USA. This has an almost identical composition and is used in the same applications. However, this material is not listed in the VdTÜV sheet and does not have its own Werkstoffnummer. An use in European pressure applications is therefore difficult.
The almost identical material is once used in Europe as 1.4529 and in the USA as UNS N08367. At Hempel, we have therefore stocked the material with double certification so that it can be used internationally.
Material Data Sheet
| Werkstoffnummer | 1.4529 |
|---|---|
| Alloy | Alloy 926 |
| Alloy 6XN | |
| EN short name | X1 NiCrMoCuN25-20-7 |
| UNS | UNS N08926 |
| UNS N08367 | |
| Registered Tradenames | |
| Ultra 6XN® | |
| AL-6XN® | |
| Cronifer 1925hMo® | |
| Standards | EN 10028-7 |
| EN 10088-2 | |
| VdTÜV Werkblatt | 502 |
| ASTM / ASME | |
| ASME SA24/ SB688/ SB625 |
Main fields of application of alloy 926
1.4529 is mainly in following applications:
Concentration and crystallization plants for salt production by evaporation
Condenser pipes and pipeline systems in power plants with highly polluted cooling water
Pump rods for oil delivery systems
Evaporators, heat exchangers, tank linings etc. and phosphoric acid production
Tanks for transport of aggressive chemical products
Distribution systems and coolers for sulfuric acid plants
Fire extinguishing systems, seawater filtration, hydraulic and injection systems of offshore technology
Flexible pipes in the offshore industry
Flue gas desulphurisation plants (FGD)
Chemical composition
| C | Si | Mn | P | S | Cr |
|---|---|---|---|---|---|
| ≤ % | ≤ % | ≤ % | ≤ % | ≤ % | % |
| 0-0.02 | 0-0.5 | 0-1.0 | 0-0.03 | 0-0.005 | 20,0-21,0 |
| Ni | Mo | Cu | N | Fe | |
|---|---|---|---|---|---|
| % | % | ≤ % | ≤ % | ≤ % | |
| 24.5-25.5 | 6-6.8 | 0,80-1.0 | 0.18-0.2 | rest |
Hot forming
The material is hot formed within a temperature range of 1200 and 900 ° C and afterwards quenched rapidly in water or air.
The annealing takes place at 1200 ° C.
After hot forming, heat treatment for optimum corrosion resistance is recommended.