Datasheet updated

2024-01-11 10:32
(supersedes all previous editions)

Alleima® 3R60 Urea Grade is a high-purity variant of ASTM 316L, specially developed for the urea industry. The grade has a guaranteed maximum ferrite content of 0.6%. Alleima® 3R60 Urea Grade is characterized by:

  • High resistance to corrosion in ammonium carbamate
  • High resistance to intergranular corrosion
  • Good weldability

Standards

  • ASTM: TP316L
  • UNS: S31603
  • EN Number: 1.4435
  • EN Name: X 2 CrNiMo 18-14-3
  • W.Nr.: 1.4435
  • DIN: X 2 CrNiMo 18 14 3
  • SS: 2353
  • BS: 316S13

Urea specifications issued by
Stamicarbon
Snamprogetti
Urea Casale
Kellogg

Product standards
ASTM A213, A312
EN 10216-5
DIN 17458

Chemical composition (nominal)

Chemical composition (nominal) %
C Si Mn P S Cr Ni Mo
≤0.020 0.4 1.7 ≤0.015 ≤0.010 17.5 14 2.6

Applications

Typical urea plant applications of Alleima® 3R60 Urea Grade are:

  • Carbamate condensers
  • Scrubbers
  • Decomposers
  • High pressure piping.

Corrosion resistance

The low ferrite and impurity contents of Alleima® 3R60 Urea Grade make it highly resistant to general and intergranular corrosion in the process solutions occurring in the manufacture of urea.

Alleima® 3R60 Urea Grade easily meets the Huey test and selective attack requirements specified by Stamicarbon, Snamprogetti and Urea Casale. The general corrosion rate is normally set at 0.6 mm/year maximum for unsensitized material (24mpy, 3.3um/48h).

Fabrication

Bending

Annealing after cold bending is not normally necessary, but the decision must be made after taking account of degree of bending and the operating conditions. Heat treatment, if any, should take the form of solution annealing, see under "Heat treatment". Hot bending is carried out at 1100–850°C (2010–1560°F) and should be followed by solution annealing.

Machining

The mechanical machining of stainless steels always requires an adjustment to cutting to data and machining method to give satisfactory results. When turning is undertaken with carbide tipped tools, the cutting speed should be reduced by 30% for finish machining and 60% for rough machining, compared with the cutting speeds applied for AISI 316. Much the same applies to other operations. If high speed steel tools are used, approximately the same cutting speed can be used as for AISI 316.

Detailed recommendations for the choice of tools and cutting data are provided in brochure S-1,462-ENG. Select data as for grade 5R60 (AISI 316), taking into account the above comments.

Forms of supply

Seamless tube and pipe- finishes and dimensions
Seamless tube and pipe in Alleima 3R60™ Urea Grade is supplied in dimensions up to 260 mm outside diameter in the solution annealed and white pickled condition, or solution annealed by a bright annealing process.
U-tubes can be supplied on request.

Other forms of supply

  • Urea high pressure pipe fittings and flanges

Filler metals for welding
The sizes listed below are Alleima stock standard. Local market stocks comprise sizes in common demand. For technical information on the filler metal please refer to brochures S-2361-ENG, S-2362-ENG and S-2366-ENG.

Heat treatment

Tubes are delivered in the heat treated condition. If additional heat treatment is needed after further processing the following is recommended.

Solution annealing

1050-1100°C (1920-2010°F), 5-20 minutes, rapid cooling in water.

Mechanical properties

For pipe with wall thicknesses greater than 10 mm (0.4 in.) the proof strength may fall short of the stated values by about 10 MPa (1.4 ksi). (1 N/mm2 = 1 MPa)

At 20°C (68°F) Metric units
Proof strength
Tensile strength Elong.
Hardness
Rp0.2a) Rp1.0a) Rm Ab) A2" HRB
MPa MPa MPa % %
≥190 ≥235 490-690 ≥40 ≥35 ≤90
At 68°F Imperial units
Proof strength
Tensile strength Elong.
Hardness
Rp0.2a) Rp1.0a) Rm Ab) A2" HRB
ksi ksi ksi % %
≥28 ≥34 71-100 ≥40 ≥35 ≤90

1 MPa = 1 N/mm2
a) Rp0.2 and Rp1.0 correspond to 0.2% offset and 1.0% offset yield strength, respectively.
b) Based on L0 = 5.65 √S0 where L0 is the original gauge length and S0 the original cross-section area.

The impact energy (Charpy V) at -60 °C (-75 °F) is minimum 150 J (110 ft-lb)

At high temperatures

Metric units
Temperature Proof strength Tensile strength
Rp0.2 Rp1.0 Rm
°C MPa MPa MPa
min. min. min.
50 180 225 470
100 165 200 450
150 150 180 430
200 140 165 415
250 130 155 410
300 120 145 400
350 115 140 395
400 110 135 390
Imperial units
Temperature Proof strength Tensile strength
Rp0.2 Rp1.0 Rm
°F ksi ksi ksi
min. min. min.
200 25 29 66
400 20 24 60
600 17 21 58
800 16 19 56

Physical properties

Density: 8.0 g/cm3, 0.29 lb/in3

Thermal conductivity
Temperature, °CW/m °CTemperature, °FBtu/ft h °F
20 14 68 8
100 15 200 8.5
200 17 400 10
300 18 600 10.5
400 20 800 11.5
500 21 1000 12.5
600 23 1100 13
Specific heat capacity
Temperature, °CJ/kg °CTemperature, °FBtu/lb °F
20 485 68 0.11
100 500 200 0.12
200 515 400 0.12
300 525 600 0.13
400 540 800 0.13
500 555 1000 0.13
600 575 1100 0.14
Thermal expansion 1)
Temperature, °CPer °CTemperature, °FPer °F
30-100 16.5 86-200 9.5
30-200 17 86-400 9.5
30-300 17.5 86-600 10
30-400 18 86-800 10
30-500 18 86-1000 10
30-600 18.5 86-1200 10.5
30-700 18.5 86-1400 10.5

1) Mean values in temperature ranges (x10-6)

Modulus of elasticity 1)
Temperature, °CMPaTemperature, °Fksi
20 200 68 29.0
100 194 200 28.2
200 186 400 26.9
300 179 600 25.8
400 172 800 24.7
500 165 1000 23.5

1) (x103)

Welding

The weldability of Alleima® 3R60Urea grade is good. Welding must be carried out without preheating and subsequent heat treatment is normally not required. Suitable methods of fusion welding are manual metal-arc welding (MMA/SMAW) and gas-shielded arc welding, with the TIG/GTAW method as first choice.

For Alleima® 3R60 Urea grade, heat input of <1.5 kJ/mm and interpass temperature of <100°C (210°F) are recommended.

Recommended filler metals

TIG/GTAW or MIG/GMAW welding

ISO 14343 S 25 22 2 N L (e.g. Exaton 25.22.2.LMn)

MMA/SMAW welding

ISO 3581 E 25 22 2 N L B (e.g. Exaton 25.22.2.LMnB)


Disclaimer: Recommendations are for guidance only, and the suitability of a material for a specific application can be confirmed only when we know the actual service conditions. Continuous development may necessitate changes in technical data without notice. This datasheet is only valid for Alleima materials.