Steel P355QL2
EN 1.8869
A quenched-and-tempered fine-grain pressure vessel steel similar to P355QL1 but with tighter guaranteed impact toughness down to -60°C, for the most demanding low-temperature pressure equipment applications.
Reference datasheet — P355QL2 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the QT condition
P355QL2 tempers and conditions
P355QL2 is supplied in 4 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Q+T | Thickest standard section; lowest guaranteed strength and the most demanding hardenability case. | 380 | 520 | 25 | 155 HB | 7.8 % IACS |
Q+T | Heavy plate condition; same heat treatment with slightly reduced guaranteed yield due to section size. | 400 | 540 | 25 | 160 HB | 7.8 % IACS |
Q+T + stress relieved / simulated PWHT | Ordered when the vessel will receive post-weld heat treatment; properties are certified after a simulated PWHT cycle (typ. 530–580 °C). | 400 | 535 | 27 | 158 HB | 7.8 % IACS |
QTDefault Quenched and tempered | Standard supply condition for plate up to 50 mm; full 355 MPa minimum yield and -60 °C impact guarantee. | 420 | 550 | 26 | 165 HB | 7.8 % IACS |
Supply forms, finishes and certifications
Ways P355QL2 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Z35 | Q+T with Z35 through-thickness quality | Certification |
What is P355QL2?
A quenched-and-tempered fine-grain pressure vessel steel similar to P355QL1 but with tighter guaranteed impact toughness down to -60°C, for the most demanding low-temperature pressure equipment applications. P355QL2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F). P355QL2 has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 53% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi).
What is P355QL2 used for?
- Cryogenic pressure vessels
- Arctic service tanks
- Boilers
- Low-temperature piping
Advantages
- Tough — resists crack growth — 150 MPa·√m (136.5 ksi·√in), better than 96% of steel grades
- Ductile — tolerates forming and impact — 26%, better than 82% of steel grades
- Readily welded — 82/100, better than 81% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
P355QL2 properties
Typical room-temperature values for P355QL2-QT; bars are the position among steel grades.
Physical3
P355QL2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,460°C (2,660 °F).
Mechanical16
P355QL2 has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 53% of steel grades. Elongation at break is 26% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P355QL2 is rated for continuous service to 400°C (752 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P355QL2 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of P355QL2 takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 20%.
Manufacturability7
P355QL2's machinability is good (58/100, better than 75% of steel grades); weldability very good (82/100); formability good (65/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. P355QL2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with P355QL2
Is P355QL2 easy to machine?
Machines like a medium-strength Q&T C-Mn steel at ~60 % of AISI 1212; use rigid setups, coated carbide and moderate speeds — avoid heavy grinding heat that could locally over-temper.
Can P355QL2 be welded?
Very good weldability (CEV typically ≤0.45); use low-hydrogen consumables matched for -60 °C CVN, preheat by thickness/CEV and cap heat input to keep the HAZ toughness the QL2 grade is bought for.
Can P355QL2 be formed, bent or molded?
Cold form with generous bend radii (≥2.5–3 t) transverse to rolling; hot forming above ~580 °C destroys the Q&T condition and requires re-quench-and-temper.
P355QL2 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cladle analysis | ≤ 0.16 | 0.13 |
| Si | ≤ 0.5 | 0.35 |
| Mn | 0.9 – 1.7 | 1.35 |
| P | ≤ 0.02 | 0.01 |
| Slow S for -60 °C toughness | ≤ 0.01 | 0 |
| Altotal Al, grain refinement | ≥ 0.02 | 0.04 |
| N | ≤ 0.02 | 0.01 |
| Cr | ≤ 0.3 | 0.15 |
| Niraises low-temperature toughness | ≤ 0.5 | 0.25 |
| Cu | ≤ 0.3 | 0.15 |
| Mo | ≤ 0.25 | 0.1 |
| Nbmicroalloying | ≤ 0.05 | 0.03 |
| Ti | ≤ 0.03 | 0.02 |
| V | ≤ 0.05 | 0.02 |
| Bhardenability, heavy sections | ≤ 0.01 | 0 |
| Zr | ≤ 0.05 | |
| Fe | balance |
What surface finishes work on P355QL2?
Not corrosion-resistant bare — shot blast to Sa 2½ and apply epoxy/zinc-rich primer, metallising or hot-dip galvanising; anodising is not applicable.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel P355QL2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.8869
How much does P355QL2 cost?
P355QL2 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
P355QL2 — frequently asked
What is P355QL2 used for?
P355QL2 is typically used for cryogenic pressure vessels, arctic service tanks, boilers and low-temperature piping. In short: toughness to -60 °C; best-weldability pressure plate; Z35 through-thickness quality.
What is the yield strength of P355QL2?
P355QL2 has a typical yield strength of 420 MPa (60.9 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 53% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is P355QL2 easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Machines like a medium-strength Q&T C-Mn steel at ~60 % of AISI 1212; use rigid setups, coated carbide and moderate speeds — avoid heavy grinding heat that could locally over-temper.
Can P355QL2 be welded?
Yes — weldability is rated very good (82/100). Very good weldability (CEV typically ≤0.45); use low-hydrogen consumables matched for -60 °C CVN, preheat by thickness/CEV and cap heat input to keep the HAZ toughness the QL2 grade is bought for.
What surface finishes work on P355QL2?
Not corrosion-resistant bare — shot blast to Sa 2½ and apply epoxy/zinc-rich primer, metallising or hot-dip galvanising; anodising is not applicable.
Can P355QL2 be formed, bent or molded?
Cold form with generous bend radii (≥2.5–3 t) transverse to rolling; hot forming above ~580 °C destroys the Q&T condition and requires re-quench-and-temper.
What is the maximum service temperature of P355QL2?
P355QL2 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does P355QL2 cost?
P355QL2 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10028-6 — Flat products for pressure purposes, Part 6: Weldable fine grain steels, quenched and tempered — CEN (2017)
- EN 10164 — Steel products with improved deformation properties perpendicular to the surface — CEN (2018)
- EN 13445-3 — Unfired pressure vessels: Design (material physical data) — CEN (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Quenched and tempered pressure vessel plate (P355QL1/QL2) datasheets — Dillinger / thyssenkrupp Steel (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.