S31254 (254SMO) and S310MoLN (1.4466), while both are austenitic stainless steels, have distinct chemical formulations. S31254 contains higher levels of molybdenum (6%) and copper (0.7%), while S310MoLN is characterized by its higher chromium content (25%) and nitrogen addition (0.16%). HT PIPE is a leading stockist and global exporter with over 15 years of expertise in international trade. We supply astm a312 uns s31254 pipes, 310moln stainless steel plates, round bars, and a comprehensive range of pipe fittings, flanges, and valves. Contact us now for free quotes and personalized product information.
s31254 steel and 1.4466 chemical composition
| Chemical Element | S31254 (254 SMO) | S310MoLN (Alloy 310MoLN) |
|---|---|---|
| Chromium (Cr) | 19.5 - 20.5% | 24.0 - 26.0% |
| Nickel (Ni) | 17.5 - 18.5% | 21.0 - 23.0% |
| Molybdenum (Mo) | 6.0 - 6.5% | 2.0 - 3.0% |
| Nitrogen (N) | 0.18 - 0.22% | 0.14 - 0.20% |
| Manganese (Mn) | ≤ 1.0% | ≤ 2.0% |
| Copper (Cu) | 0.5 - 1.0% | ≤ 0.3% |
| Carbon (C) | ≤ 0.020% | ≤ 0.020% |
| Silicon (Si) | ≤ 0.80% | ≤ 0.40% |
| Phosphorus (P) | ≤ 0.030% | ≤ 0.020% |
| Sulfur (S) | ≤ 0.005% | ≤ 0.003% |
| PREN Value (Pitting Resistance Equivalent) |
≥ 43 (Cr + 3.3Mo + 16N) |
≈ 36 - 38 (Cr + 3.3Mo + 16N) |
alloy s254smo and alloy 310moln mechanical property
| Mechanical Property | S31254 (254 SMO) | S310MoLN (Alloy 310MoLN) |
|---|---|---|
| Tensile Strength (Rm) | ≥ 650 MPa | ≥ 700 MPa |
| Yield Strength (Rp0.2) | ≥ 300 MPa | ≥ 430 MPa |
| Elongation at Break (A5) | ≥ 35% | ≥ 40% |
| Brinell Hardness (HBW) | ≤ 223 | ≤ 230 |
| Modulus of Elasticity (E) | ~ 200 GPa | ~ 200 GPa |
| Density (ρ) | 8.0 g/cm³ | 8.0 g/cm³ |
uns s31254 and ss310moln Pitting and Crevice Corrosion Resistance
S31254, due to its ultra-high molybdenum content (6%) and nitrogen addition, exhibits an extremely high pitting resistance equivalent value (PREN ≥ 43). The PREN value is calculated as: %Cr + 3.3 × %Mo + 16 × %N, making S31254 virtually invincible in chloride-containing environments.
S310MoLN has a PREN value of approximately 36-38. While lower than S31254, it's still significantly higher than conventional stainless steels, making it suitable for most moderately corrosive environments.
stainless steel s31254 and stainless steel 310moln Stress Corrosion Cracking (SCC) Resistance
Both materials exhibit excellent resistance to stress corrosion cracking, but S31254 performs slightly better in high-temperature, high-chloride environments due to its higher nickel and molybdenum content.
astm 254smo abd astm 310moln Acid Corrosion Resistance
S31254 excels in sulfuric, phosphoric, and organic acid environments due to its copper content, while S310MoLN's high chromium content provides better resistance in oxidizing acids like nitric acid.
ss254smo and s310moln High-Temperature Performance
S310MoLN, thanks to its high chromium content, has a natural advantage in high-temperature oxidation resistance, maintaining stability in intermittent service up to 1100°C and continuous service up to 1000°C. This makes it a popular choice for heat treatment equipment, boilers, and heat exchangers.
The high-temperature performance of S31254 is relatively limited. Excessive molybdenum content actually reduces its stability at high temperatures, and long-term operating temperatures generally do not exceed 400°C. However, it still maintains good performance in high-temperature corrosive environments (such as sulfur-containing atmospheres).
Conclusion
The core advantages of S31254 (254 SMO) are:
Superior Corrosion Resistance: Particularly against pitting, crevice corrosion, and stress corrosion cracking, thanks to its ultra-high molybdenum content (6%) and high PREN value (≥43). The added copper also grants good resistance to sulfuric acid environments.
The core advantages of S310MoLN (Alloy 310MoLN) are:
High Strength and Excellent High-Temperature Performance: The significantly higher yield strength allows it to withstand greater loads in structural applications. The high chromium content provides outstanding high-temperature oxidation resistance (up to 1100°C).
