310MoLN, 1.4466, Stainless Steel
SS 310MoLN,WNR 1.4466, UNS S31050, AISI 310MoLN, Grade 310MoLN, AFNORZ 1 CND25.22AZ
310moln stainless steel grade is a fully austenitic stainless steel that does not have intermetallic phases such as intergranular carbide precipitations. For applications in urea plants 310MoLN steel grade has a specifically designed optimized chemical composition. To stabilize and strengthen the austenitic phase the nitrogen in the chemical composition helps. 310 MoLN, material gives excellent corrosion-resistance in urea carbamate environments such as high-pressure strippers. Among wrought austenitic stainless steels it has a fairly high base cost. And it has a fairly high embodied energy and a fairly low ductility.
<<310MoLN, 1.4466, Stainless Steel DATA SHEET>>
Material
| Material designation | |
| 1.4466 | SEL |
| S31050 | UNS |
| X1CrNiMoN25-22-2 | EN |
| 310 MOLN | AISI |
| Standards | |
| 10088-3 | EN ISO |
| 310MoLn A182 | ASTM |
Chemical Composition
| SS 310MoLN | WNR 1.4466 | UNS S31050 | AISI 310MoLN | GRADE 310MoLN | AFNORZ1C ND25.22AZ | |
| Carbon | 0.020max | 0.020max | 0.020max | 0.020max | 0.020max | 0.020max |
| Manganese | 2.00max | 2.00max | 2.00max | 2.00max | 2.00max | 2.00max |
| Chromium | 24.0-26.0 | 24.0-26.0 | 24.0-26.0 | 24.0-26.0 | 24.0-26.0 | 24.0-26.0 |
| Phosphorus | 0.025max | 0.025max | 0.025max | 0.025max | 0.025max | 0.025max |
| Sulfur | 0.010max | 0.010max | 0.010max | 0.010max | 0.010max | 0.010max |
| Molybdenum | 2-2.50 | 2-2.50 | 2-2.50 | 2-2.50 | 2-2.50 | 2-2.50 |
| Nickel | 21.0-23.0 | 21.0-23.0 | 21.0-23.0 | 21.0-23.0 | 21.0-23.0 | 21.0-23.0 |
| Nitrogen | 0.10-0.16 | 0.10-0.16 | 0.10-0.16 | 0.10-0.16 | 0.10-0.16 | 0.10-0.16 |
| Silicon | 0.70max | 0.70max | 0.70max | 0.70max | 0.70max | 0.70max |
| Iron | Bal | Bal | Bal | Bal | Bal | Bal |
Mechanical Properties
| SS 310MoLN | WNR 1.4466 | UNS S31050 | AISI 310MoLN | GRADE 310MoLN | AFNORZ1 CND25.22AZ | |
| Tensile Strength, Mpa(psi) | 540-740 (78320-107327) | 540-740 (78320-107327) | 540-740 (78320-107327) | 540-740 (78320-107327) | 540-740 (78320-107327) | 540-740 (78320-107327) |
| Yield Strength, Mpa(psi) | 250(36259) | 250(36259) | 250(36259) | 250(36259) | 250(36259) | 250(36259) |
| Elongation % | 40 | 40 | 40 | 40 | 40 | 40 |
| Reduction in Area, % | – | – | – | – | – | – |
| Hardness, Brinell | 95 | 95 | 95 | 95 | 95 | 95 |
The grade is characterized by :
- Excellent resistance to corrosion in ammonium carbamate and nitric acid
- Excellent resistance to intergranular corrosion
- High resistance to pitting and crevice corrosion
- Good weldability
Applications:
- Striper Tubes
- Outerlayer of bimetallic
- Ferrules
- Carbamate Condensers
- Decomposers
- Reactor Coils
General corrosion
- S31050 was originally developed for stripper tubes used in the production of urea.
- S31050 has excellent corrosion resistance in urea/carbamate solutions at high pressures andtemperatures.
- S31050 is also highly resistant to inorganic acids
Intergranular corrosion
- S31050 ishighly resistant to intergranular corrosion after welding.
Pitting and crevice corrosion
- S31050 has very good resistance to pitting, and is also far more resistant to crevice corrosion than ASTM 316L.
Stress corrosion cracking (SCC)
- Conventionalausteniticstainless steels of type ASTM 304 and 316 are susceptible to stress corrosion cracking (SCC) in chloride- bearing solutions at temperatures exceeding about 60°C (140°F). The higher nickel content makes S31050 slightly more resistant
Erosion corrosion
- The good mechanical strength of S31050 makes it resistant to erosion-corrosion. Ferrules for urea strippers are oneapplicationwhere this property is utilised.
Weldability
- Theweldability of S31050 is good. Welding must be carried out without preheating, and normally there is noneed for any subsequent heat treatment.
- S31050 has lowthermal conductivity and high thermal expansion.
