Material Data Sheet
Duplex Stainless Steel - SM25CRU-80
SM25CRU is a Duplex Stainless Steel material. SM25CRU has been developed for usage in seawater injection applications with controlled amount of dissolved oxygen. This material has been newly developed by NIPPON STEEL to meet industry demand for fit for purpose materials capable to reduce overall completion costs. SM25CRU benefits from NIPPON
STEEL's unrivaled know how in manufacturing CRA (Corrosion Resistance Alloys) materials and best in class quality control.
SM25CRU is manufactured based on API 5CT / ISO 11960 and API 5CRA / ISO 13680.
Diameters: 4 1/2” to 7 (Smaller or larger sizes may be available upon request)
Weights: as per API 5CT/ ISO 11960 and API 5CRA/ ISO 13680.
Special application: Please contact NIPPON STEEL engineer, should you require specific size, weight, drift, or any other characterization.
•Proprietary SM25CRU series. TGP-4702 (latest revision) for SM25CRU-80
•API 5CT / ISO11960
•API RP 5C1 / ISO 10405
•API 5CRA / ISO 13680
•VAM® Running Book
•NIPPON STEEL Storage and handling procedure for CRA materials
Seawater handling systems featuring some presence of dissolved oxygen.
Its primary function is Tubing and Liner, sections permanently exposed to injection fluids
Typical application of SM25CRU material is for seawater injection systems where some presence of dissolved O2 is expected but controlled. In this case, a clear definition of the
expected dissolved oxygen content (O2) will need to be ascertained to determine SM25CRU suitability versus anticipated service temperatures.
In addition, compatibility with packer & completion fluids (brines and additives), matrix acidizing fluids, and scale dissolvers need to be ascertained.
For a more detailed assessment please contact NIPPON STEEL engineers.
| Process | Description |
| Steel making | Steel shall be made by electric furnace process or blast furnace followed by Vacuum Oxygen Decarburization (VOD) process &/or Argon Oxygen Decarburization (AOD) Process |
| Pipe making | Seamless |
| Heat treatment | Solution Annealing Process |
(mass %)
| Grade | C | Si | Mn | Cu | Ni | Cr | Mo | W | N | PREN |
| SM25CRU-80 | ≤ 0.03 | ≤ 0.80 | 1.50~7.50 | 1.0~3.0 | 3.5~6.5 | 24.5~26.5 | 0.75~2.00 | - | 0.10~0.35 | ≥ 31.0 |
|
YIELD STRENGTH |
TENSILE STRENGTH |
ELONGATION |
HARDNESS |
TECHNICAL NOTE | |
| Min | Max | Min | Min | Max | - |
| 80 | 105 | 90 | 25 | 30 | |
| UNIT | 25℃ | 50℃ | 100℃ | 150℃ | 200℃ | 250℃ | |
| Density | Kg/m3 | 7730 | 7720 | 7710 | 7690 | 7670 | 7660 |
| Young’s modulus | GPa | 203 | 202 | 198 | 195 | 191 | 185 |
| Poisson’s Ratio | - | 0.29 | 0.29 | 0.29 | 0.29 | 0.29 | 0.30 |
| Tensile strength de-rating | % | 100 | 96.1 | 89.6 | 85.8 | 84.2 | - |
| Yield strength de-rating | % | 100 | 94.8 | 85.8 | 78.7 | 74.9 | - |
| Thermal Diffusivity | x10-6m-2/s | 3.66 | 3.72 | 3.84 | 3.95 | 4.04 | 4.09 |
| Heat Capacity | x106J/m3℃ | 3.69 | 3.77 | 3.92 | 4.03 | 4.14 | 4.26 |
| Thermal Conductivity | W/m℃ | 13.5 | 14.0 | 15.1 | 16.0 | 16.9 | 17.6 |
| Specific Heat | J/Kg.℃ | 478 | 488 | 508 | 524 | 540 | 556 |
| Thermal expansion | x10-6/℃ | - | 12.9 | 13.3 | 13.6 | 14.0 | 14.2 |
Duplex terminology comes from the material dual micro structure composed of approximately 50% Ferrite and 50% Austenite. The intention in using this dual structure is to maintain the same pitting index in the ferrite and austenite phases, while keeping a high Yield strength in solution treated condition, as illustrated in the PREN formula:
PREN = Cr + 3.3(Mo+0.5W) + 16N (in mass %)
A typical application where Super Duplex material (PREN > 40) has been used is for water handling systems (water injection, WAG wells) where presence of dissolved oxygen (DO) is expected .
SM25CRU, with a leaner chemistry (PREN > 30), can still be applied in similar applications but where the amount of dissolved oxygen is controlled.
SM25CRU has been physically fit for purpose tested in sea flow loop testers to check its capability to withstand oxygen contamination. Through these tests it was confirmed SM25CRU can be used in water handling systems (Sea water injection, WAG wells) when DO is continuously maintained below 50 ppb (part per billion). Material can tolerate as well
punctual system oxygen excursions, but amount & frequency of these excursions shall be verified in advance to ascertain material suitability.
For additional information about material performances please contact NIPPON STEEL engineers
While state of the art HSE rules are applied throughout NIPPON STEEL manufacturing process, proprietary and specific HSE regulations shall be applied along the life cycle of the pipe until it reaches its final position in the well, according to each operator’s rules. This particularly applies to all phases of handling and transportation, assembly on the rig floor, and rig return if applicable. OCTG are heavy and by nature unstable. Special care shall be paid to potential risks of injury whenever handling OCTGs. Walking on pipes shall be avoided at all times. Usage of Personal Protection Equipment (PPE) is mandatory. Equipment and procedures will be established to capture the possible wastes generated during maintenance (cleaning, coating, doping) and disposed according to local regulations. This applies in particular to storage dope, running dope, or cleaning water wastes.
Best practices for transportation, handling and storage of OCTG in general are covered by ISO 10405 / API RP5C1. VAM Book is also a good source of handling practices for VAM connections. In addition to these general rules, specific care is recommended pertaining to SM25CRU , because improper handling could affect the material performances and by extension the corrosion resistance :
• Prevention of Spot Hardening
• Prevention of Iron contamination
• Adapted running equipment and practices
• Prevention of corrosion on rig returns, particularly in presence of completion fluids
For more specific information please refer to NIPPON STEEL Storage and handling procedure for CRA materials, or contact NIPPON STEEL engineers.