Steel P690QL2
EN 1.8888
P690QL2 (1.8888) is the highest-toughness member of the P690 quenched-and-tempered nickel-alloy family, with impact properties guaranteed to −60 °C, lower than QL1.
Reference datasheet — P690QL2 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
P690QL2 tempers and conditions
P690QL2 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 |
|---|---|---|---|---|---|---|
QT | Extra-heavy section band; choose when wall thickness governs and reduced minimum properties are acceptable. | 690 | 790 | 18 | 21 HRC | 6.9 % IACS |
QT | Heavy plate thickness band with slightly reduced guaranteed strength due to lower through-thickness quench rate. | 710 | 830 | 18 | 23 HRC | 6.9 % IACS |
quenched, tempered and stress relieved (PWHT simulated) | Ordered when the fabricated vessel will see post-weld heat treatment; properties certified after simulated PWHT, typically 10–40 MPa lower strength. | 720 | 820 | 19 | 23 HRC | 6.9 % IACS |
QTDefault Quenched and tempered | Standard as-delivered condition for plate up to 50 mm; full 690 MPa yield with -60 °C impact guarantee. | 750 | 840 | 18 | 25 HRC | — |
What is P690QL2?
P690QL2 (1.8888) is the highest-toughness member of the P690 quenched-and-tempered nickel-alloy family, with impact properties guaranteed to −60 °C, lower than QL1. Typical delivered values are 750 MPa yield, 840 MPa tensile, 18 % elongation and 255 HB (25 HRC), supplied as plate in QT, QT-50-100, QT-100-150 and QT+SR conditions for cold-climate load-bearing weldments. Weldability is moderate (score 60) with CEV around 0.6–0.7, formability is limited (score 40), and service is capped near 400 °C. P690QL1 or plain P690Q are cheaper where −60 °C impact values are not specified. P690QL2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,430°C (2,606 °F). P690QL2 has a yield strength of 750 MPa (109 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 84% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is P690QL2 used for?
- arctic and offshore structures
- mobile crane components
- pressure vessels
- heavy-duty structural steelwork
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- High strength — 750 MPa (109 ksi), better than 84% of steel grades
Limitations
- Difficult to machine — 35/100, worse than 84% of steel grades
P690QL2 properties
Typical room-temperature values for P690QL2-QT; bars are the position among steel grades.
Physical3
P690QL2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,430°C (2,606 °F).
Mechanical16
P690QL2 has a yield strength of 750 MPa (109 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 84% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P690QL2 is rated for continuous service to 400°C (752 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 12.5 µm/m·K (6.94 µin/in·°F).
Electrical2
P690QL2 has an electrical resistivity of 2.5×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of P690QL2 takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability6
P690QL2's machinability is fair (35/100, worse than 84% of steel grades); weldability good (60/100); formability fair (40/100).
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. P690QL2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with P690QL2
Is P690QL2 easy to machine?
Machine as a 250 HB Q&T alloy steel: rigid setups, coated carbide, moderate speeds (~80–120 m/min) and positive feed to stay under the work-hardened skin.
Can P690QL2 be welded?
Weldable with low-hydrogen consumables only; CEV ≈ 0.6–0.7 requires preheat/interpass typically 100–175 °C, controlled heat input (≈1.0–2.5 kJ/mm) and matching 690 MPa filler to preserve -60 °C toughness.
Can P690QL2 be formed, bent or molded?
Cold bend with generous radii (about 3× thickness transverse to rolling) and avoid flame-straightening above the tempering temperature, which permanently softens the plate.
P690QL2 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, EN 10028-6 | ≤ 0.2 | 0.16 |
| Si | ≤ 0.8 | 0.3 |
| Mn | 0.4 – 1.7 | 1.2 |
| P | ≤ 0.02 | 0.01 |
| S | ≤ 0.01 | 0 |
| Nimain contributor to low-temperature toughness | ≤ 2.5 | 1.5 |
| Cr | ≤ 1.5 | 0.5 |
| Mo | ≤ 0.7 | 0.45 |
| Cu | ≤ 0.5 | 0.2 |
| V | ≤ 0.12 | 0.04 |
| Nb | ≤ 0.06 | 0.02 |
| Ti | ≤ 0.05 | 0.02 |
| Zr | ≤ 0.05 | |
| Bhardenability booster | ≤ 0.01 | 0 |
| N | ≤ 0.02 | 0.01 |
| Altotal Al, for grain refinement | ≥ 0.02 | 0.04 |
| Fe | balance |
What surface finishes work on P690QL2?
No corrosion resistance in bare form — shot blast to Sa 2½ then epoxy/zinc-rich primer or metallize; avoid uncontrolled electroplating because of hydrogen embrittlement risk at this strength level.
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 P690QL2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.8888
How much does P690QL2 cost?
P690QL2 is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
P690QL2 — frequently asked
What is P690QL2 used for?
P690QL2 is typically used for arctic and offshore structures, mobile crane components, pressure vessels and heavy-duty structural steelwork. In short: −60 °C impact toughness; toughest P690 variant; 690 MPa arctic-grade plate.
What is the yield strength of P690QL2?
P690QL2 has a typical yield strength of 750 MPa (109 ksi) and a tensile strength of 840 MPa (122 ksi) — stronger than 84% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is P690QL2 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Machine as a 250 HB Q&T alloy steel: rigid setups, coated carbide, moderate speeds (~80–120 m/min) and positive feed to stay under the work-hardened skin.
Can P690QL2 be welded?
Yes — weldability is rated good (60/100). Weldable with low-hydrogen consumables only; CEV ≈ 0.6–0.7 requires preheat/interpass typically 100–175 °C, controlled heat input (≈1.0–2.5 kJ/mm) and matching 690 MPa filler to preserve -60 °C toughness.
What surface finishes work on P690QL2?
No corrosion resistance in bare form — shot blast to Sa 2½ then epoxy/zinc-rich primer or metallize; avoid uncontrolled electroplating because of hydrogen embrittlement risk at this strength level.
Can P690QL2 be formed, bent or molded?
Cold bend with generous radii (about 3× thickness transverse to rolling) and avoid flame-straightening above the tempering temperature, which permanently softens the plate.
What is the maximum service temperature of P690QL2?
P690QL2 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does P690QL2 cost?
P690QL2 is a budget-cost steel ($), 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 10027-2 — Material number 1.8888 — CEN (2015)
- EN 1011-2 — Welding recommendations for ferritic steels — CEN (2001)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol. 19 — Fatigue and Fracture — ASM International (1996)
- Quenched and tempered 690 MPa pressure-vessel plate datasheets (Dillinger / SSAB / thyssenkrupp) — various mills (2023)
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.