Specification:
ASTM A 269/A 213/A 1016, NACE MR0175, PED 97/23 EC
EN 10216-5 / NORSOK M-650 MDS R18
Maximum exposure temperature:400°C / 848°F
6Mo/254SMO is a super austenitic stainless steel with a minimum of 6% of molybdenum and a high level of nitrogen, providing high resistance to pitting and crevice corrosion, combined with high strength, compared with other austenitic stainless steels as 316L, 317L and 904L. These alloys where developed for use in halide containing environments such as brackish water, seawater, hydrochloric acid and sculpture acid. The increased levels of molybdenum combined with chromium and nitrogen provide levels of pitting and crevice corrosion resistance more typically associated with higher alloy 625 (UNS NO6625).
Characteristics:
Market applications:
Technical details
| Technical composition (%) | Fe | Cr | Ni | Mo | Mn | Cu | Si | P | N | C | S |
| 254SMO min | Bal. | 19.5 | 17.5 | 6.0 | - | 0.5 | - | - | 0.18 | - | - |
| max | - | 20.5 | 18.5 | 6.5 | 1.00 | 1.0 | 0.80 | 0.03 | 0.25 | 0.030 | 0.010 |
| 6MO min | Bal. | 20.0 | 23.5 | 6.0 | - | - | - | - | 0.18 | - | - |
| max | - | 22.0 | 25.5 | 7.0 | - | 0.75 | 1.00 | 0.04 | 0.25 | 0.040 | 0.030 |
| Mechanical Properties | 254SMO | 6MO |
| Tensile strenght (mpa, min) | 650 - 850 | 675 - 875 |
| Yield strength (0.2% offset mpa, min) | 300 - 340 | 310 - 350 |
| Elongation (%, min) | 35 | 30 |
| Density / weight (g / cm3 / kg) | 8.05 | 8.05 |