P355QL2 Steel Plate for Refrigerated and Arctic Duty

A refrigerated tank rarely fails at its operating temperature. It fails during the first cooldown, during a venting event that chills the shell faster than the process model predicted, or during a winter shutdown with liquid still in the vessel. Specifying to the steady-state number is how low-temperature equipment ends up built from the wrong steel.

P355QL2 (1.8869) is the branch built for those cases. Under EN 10028-6:2017 it is delivered quenched and tempered and guarantees 27 J minimum average at −60 °C on transverse Charpy specimens, rising to 40 J at −40 °C, 60 J at −20 °C and 80 J at 0 °C. Chemistry supports the test with sulphur capped at 0.005 %. Strength stays at the family level - 355 MPa minimum yield up to 50 mm, 490–630 MPa tensile, 22 % elongation.

Refrigerated service is the hardest case for a pressure-purpose steel for a simple reason: the material gets colder faster than the process model predicts, and the consequences arrive without warning. A shell that is ductile at −20 °C can cleave at −60 °C under the same stress, at a defect that inspection had already accepted.

P355QL2 Steel Plate Mechanical Properties and Impact Energy

P355QL2 Plate Chemical Composition

Ladle analysis, maximum %, per EN 10028-6:2017:

P355QL2 Steel Plate Application Scenarios

Refrigerated and low-temperature storage tanks

• Ethylene, propylene, ammonia and LPG stored in the −40 to −60 °C band
• Shells, courses and bottoms where the cooldown rate, not the product temperature, sets the requirement
• Vessels with refrigerated vapour return and cold liquid withdrawal

Low-temperature gas transport and mobile tanks

• Road and rail tank bodies rated to −60 °C metal temperature
• ISO-type tanks and skid-mounted vessels for liquefied gas distribution
• Cargo equipment running winter routes and cold loading cycles

Cold-climate and arctic installations

• Separators, scrubbers and knock-out drums on arctic and sub-arctic sites
• Process vessels at northern and high-altitude locations where ambient sets the design metal temperature
• Outdoor equipment with cold hydrostatic testing requirements

Petrochemical low-temperature separation

• Chill trains, cold boxes and low-temperature fractionation equipment
• Demethaniser and de-ethaniser associated vessels within the −60 °C limit
• Refrigeration loop vessels and surge drums

Vessels with a cold operating case

• Equipment whose hydrotest or start-up condition is colder than its operating condition
• Seasonal and standby plant in cold climates

Boundaries worth stating

1. LNG primary containment is out of scope - storage near −162 °C belongs to 9 % nickel steel, austenitic stainless or aluminium alloys.
2. No inherent corrosion resistance - sour service, acid media and coastal exposure are handled by cladding, coating or corrosion allowance, with HIC testing where the medium requires it.
3. No elevated-temperature values - if the equipment also runs hot, those figures must be agreed at order time.

P355QL2 Steel Plate for Refrigerated and Arctic Duty Specifications

Most low-temperature vessel orders ship as cut and bevelled parts rather than full mill plates, which removes a burner-cutting step and the associated plate handling at the fabricator.

What to Send with the Enquiry

1. Drawings or cutting list - shell development, course dimensions, end blank sizes and joint preparation
2. Design conditions - lowest metal temperature, design pressure and the governing code
3. Inspection scope - certificate type (3.1 or 3.2), UT class, Z-direction category, impact temperature and energy
4. Schedule - required delivery date and destination port, so stock and mill routes can be compared honestly

P355QL2 Plate Fabrication Notes

1. Cutting - flame cutting is standard for thicker plate; the heat-affected cut edge is dressed before welding where the procedure requires it.
2. Forming - dished ends are formed inside the temperature window agreed with the mill; hot forming above the tempering temperature destroys the QT properties.
3. Welding - preheat typically 125–175 °C, PWHT normally 580–620 °C and always below the mill tempering temperature, with consumables qualified at the design temperature. Full reasoning is on the P355QL2 boiler steel plate page.
4. Inspection - UT class and Z-direction category agreed before production rather than raised after rolling.

Why Choose GNEE for P355QL2 Orders

1. Cut to your cutting list - shells, courses and end blanks delivered as sized parts rather than stock plates.
2. Inspection arranged to the project - UT, Z-direction and impact testing booked with production; third-party witness for EN 10204 3.2.
3. Export packing and logistics - seaworthy packing, heat-number marking and container loading planned at quotation stage.
4. Lead time quoted honestly - stock and mill-rolled routes shown separately, so schedule risk is visible before you commit.
5. Cold-service export since 2008 - GNEE Steel supplies cut-to-size plate for refrigerated and arctic vessels, with seaworthy packing and documentation prepared for the destination port.

Give us the destination port - we quote landed cost, export packing and lead time in a single reply.

FAQ

Can P355QL2 be used for LNG storage?
No. LNG containment near −162 °C requires 9 % nickel steel, austenitic grades or aluminium alloys. P355QL2 is a −60 °C grade.

Can you supply blanks cut for dished ends and shell courses?
Yes. Send the cutting list or blank dimensions and we quote the finished parts, including bevelling where the joint preparation is specified.

What supplementary testing is usual for low-temperature vessels?
UT to EN 10160 or ASTM A578 with the class stated, Z-direction testing to EN 10164 (Z25/Z35) at restrained joints, and Charpy testing at the specified temperature - each a separate line item.

Does the plate need PWHT after welding?
That depends on thickness, joint restraint and the governing code, not on the grade alone. Where PWHT is applied, it stays below the mill tempering temperature, normally in the 580–620 °C band.