Alleima® 3R60 Urea Grade Tube and pipe, seamless

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)

1 MPa = 1 N/mm²
a) R_p0.2 and R_p1.0 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

Physical properties

Density: 8.0 g/cm³, 0.29 lb/in³

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

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)