1.4466

  • UNS S31050
  • UREA 25.22.2
  • 310MoLN

UREA 25.22.2 chemical composition has been optimised for specific uses in Urea plants. It is a 310L modified austenitic stainless steel with low carbon, low
silicon and high nitrogen additions in order to stabilize and strengthen the austenitic phase. The alloy is particularly designed for improved corrosion resistance properties in urea carbonate environments including strippers. The grade is also well designed for resistance in wet corrosive conditions due to its high contents of chromium, molybdenum and nitrogen (PREN > 33). UREA 25.22.2 is designed for the fabrication of lining interiors in Urea units or complementary products (pipes, fittings…). The grade can be used for urea strippers.

Mechanical Properties

Tensile strength:540-740N/mm²
Yield strength 0,2% :250≥ N/mm²
Elongation:35/30≥ %
Hardness Brinell:240≤ HB

Chemical Composition

Carbon

C

0,020% max

Silicon

Si

0,40% max

Magnese

Mn

2% max

Phosphorus

P

0,020%max

Sulphur

S

0,010% max

Chromium

Cr

24-26%

Molybdenum

Mo

2,0-2,6%

Nickel

Ni

21-23,5%

Nitrogen

N

0,10-0,15%

Heat Treatment

heat treatment (1140°-1180°C –2084-2156°F) and water quenching

The corrosion resistance properties are enhanced thanks to the low carbon level, low silicon level and complementary additions of nitrogen.

Typical maximum corrosion results required following different specifications for the 25.22.2 grade after  5 periods of 48 h following ASTM A 262-C practice are:
maximum general corrosion: 1,6 μm/48 h or 65 mg/dm² per hour with a maximum depth of microcracks of 100 μm in the long direction of rolling.

  • Ferrite check 100% (less than 0,5%)
  • Measurement location chosen by  Inspector

UREA 25.22.2 can be welded with most of the welding processes : TIG, Plasma, MIG welding, as well as SMAW, SAW or FCAW processes. The alloy is sensitive
to hot cracking phenomenon due to its fully austenitic microstructure. Weld should be performed in order to obtain extra-low ferrite contents, no carbide or nitride precipitations, low silicon contents as well as no intermetallic phase precipitations. Higher manganese content products should be considered.

Marking

All material will be marked as follow:

  • Manufacturer’s name
  • Material grade
  • Size
  • Heat Number

Certification

Material will be delivered with certificate EN 10204 3.1

Other UREA grades

EURONORM/DINWERKSTOFF NR.AISIUNSBRAND NAME
X2 CrNiMo 18-14-3 1.4435 316L UG S 31603316L MOD UREA ®
3R60 UREA GRADE
X1 CrNiMoN 25-22-21.4466/1.4465310 MoLNS 3105025.22.2 ®
1.4477S32906DMV 29.7

products

Pipes, piping material

pipes

Flanges, piping material

flanges

Fittings, piping material

fittings

Plates, piping material

plates

Round Bar, piping material

bars

Forged Fittings, piping material

forged fittings