254 SMO is a high austenitic grade that has 3 times the strength possessed by stainless steel 300 series. The 254 smo pipe can resist different types of corrosion like pitting, crevice and chloride stress corrosion cracking. They also have high ductility and good impact strength. The pipes can show great performance in elevated temperature conditions and maintain their properties in a volatile environment.
The pipes are cost efficient and easy to fabricate and weld. The 254 smo stainless steel pipes can be used in sea water handling, food processing, etc. They are tough to machine due to lack of sulphur and has high work hardening rate. DIN 1.4547 seamless tube should be annealed post process to gain maximum corrosion resistance properties.
The smo 254 pipe equivalent are ASTM A814, A469, A312, A813, A240, A249, A269 and A182.
SMO 254 pipe
254 SMO tube
UNS S31254 pipe
Size | Wall Thickness | Length |
---|---|---|
1/2 " to 100 " NB | .035 to .065 inch | 6 to 12 meter |
Specification | Process | Application |
ASTM A269, A213, A312, A249 | seamless, hot rolled, annealed, welded | Equipment for handling seawater |
254 SMO tubing
254 SMO seamless pipe
DIN 1.4547 seamless tube
Elongation (min 2"): | 35% |
---|---|
Tensile Strength: | 98 ksi min |
Hardness (Rockwell B Scale): | 96 HRB max |
Yield Strength: | 45 ksi min |
STANDARD | SIS | UNS | WERKSTOFF NR. | GOST | JIS | AFNOR | EN |
---|---|---|---|---|---|---|---|
254 SMO | 2378 | S31254 | 1.4547 | – | – | Z1 CNDU 20.18.06Az | X1CrNiMoCuN20-18-7 |
254 SMO | S Sulfur | Cu Copper | C Carbon | Mn Manganese | P Phosphorus | Si Silicon | Cr Chromium | Ni Nickel | Mo Molybdenum | N Nitrogen |
---|---|---|---|---|---|---|---|---|---|---|
0.015 max | 0.50–1.00 | 0.020 max | 1.00 max | 0.030 max | 0.80 max | 19.5–20.5 | 17.5–18.5 | 6.0–6.5 | 0.18–0.22 |
The standard thickness of 254 smo tube ranges between 0.4 to 30 mm. However, they can also be customized specific to client requirements. You can calculate the 254 smo tubing thickness with the given formula: Thickness = Outside Diameter (OD) - 2 x Wall Thickness
The critical pitting temperature is measured by the s31254 pipe material resistance to localized corrosion, especially pitting. The exact temperature would depend on specific environment and surface conditions. In general, the 254 smo seamless pipe exhibits a high resistance to pitting and the temperature exceeds 50 °C.
The roughness factor of the smo 254 tubes refers to the surface roughness of the inner walls. It is depicted by the average height deviation from the mean line of the surface profile. This is an important consideration where fluid flow, cleanliness and fouling resistance are critical.
To determine the roughness factor, you need to measure the Ra value using specialized equipment like a profilometer. 254 smo generally has a smooth surface finish and their Ra value typically ranges between 0.1 to 1 µm or higher, depending on the finishing achieved.
W/moC | Temperature,oC | Btu/ft hoF | Temperature,oF |
---|---|---|---|
21 | 600 | 12.5 | 1200 |
12 | 100 | 7 | 200 |
10 | 20 | 6 | 68 |
14 | 200 | 8 | 400 |
18 | 400 | 10.5 | 800 |
16 | 300 | 9.5 | 600 |
20 | 500 | 11.5 | 1000 |
23 | 700 | 13 | 1300 |
Temperature | Proof strength | |
---|---|---|
°C | Rp1.0 | Rp0.2 |
MPa | MPa | |
min. | min. | |
200 | 225 | 190 |
100 | 270 | 230 |
400 | 190 | 160 |
300 | 200 | 170 |
500 | 180 | 148 |
J/kg °C | Temperature, °C | Btu/ft h °F | Temperature, °F |
---|---|---|---|
485 | 20 | 0.12 | 68 |
510 | 100 | 0.12 | 200 |
535 | 200 | 0.13 | 400 |
565 | 300 | 0.14 | 600 |
585 | 400 | 0.14 | 800 |
600 | 500 | 0.14 | 1000 |
615 | 600 | 0.15 | 1200 |
625 | 700 | 0.15 | 1400 |
MPa | Temperature, °C | ksi | Temperature, °F |
---|---|---|---|
195 | 20 | 28.3 | 68 |
190 | 100 | 27.6 | 200 |
182 | 200 | 27.5 | 400 |
174 | 300 | 25.1 | 600 |
166 | 400 | 23.8 | 800 |
158 | 500 | 22.5 | 1000 |
Grade | Remark | Time to failure |
---|---|---|
254 SMO | No attack | No failure (1000 h) |
0.4 to 30.00 mm
it is superaustenitic stainless steel
12.5%
exceeds 76°C
white pickled and solution annealed