Steel P500Q-QL2
Grade
EN 1.8873
QL2 = p500QL2
Highest toughness sub-grade for cryogenic-leaning service and heavy restraint welds.
Values for the QL2 condition
Other P500Q tempers and conditions
P500Q is listed in 6 conditions; see the grade overview at P500Q.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Q&T heavy plate, 50–100 mm (reduced minimum yield) | Same heat treatment on heavy gauge; specify when plate thickness exceeds 50 mm and lower guaranteed yield is acceptable. | 510 | 640 | 20 | 17 HRC | 7.2 % IACS |
Stress relieved | Condition of fabricated vessels after PWHT; expect modest loss of yield and hardness. | 510 | 630 | 21 | 15 HRC | 7.2 % IACS |
QTDefault Quenched and tempered | Standard delivery condition for plate up to ~50 mm; impact tested at 0 °C. | 545 | 660 | 20 | 19 HRC | 7.2 % IACS |
P500QH | Choose when the vessel sees elevated design temperature and guaranteed hot yield values are needed. | 545 | 660 | 20 | 19 HRC | 7.2 % IACS |
P500QL1 | Use for cold-service pressure equipment down to about -40 °C. | 545 | 660 | 20 | 19 HRC | 7.2 % IACS |
QL2This page P500QL2 | Highest toughness sub-grade for cryogenic-leaning service and heavy restraint welds. | 545 | 660 | 21 | 18 HRC | 7.2 % IACS |
What is P500Q-QL2?
P500Q-QL2 is P500Q in the QL2 grade — highest toughness sub-grade for cryogenic-leaning service and heavy restraint welds. P500Q-QL2 has a yield strength of 545 MPa (79 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 70% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi). P500Q-QL2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). QT is the default condition FabDigit quotes; QL2 is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 120 MPa·√m (109.2 ksi·√in), better than 81% of steel grades
P500Q-QL2 properties
Typical room-temperature values for P500Q-QL2; 24 are specific to this condition. Other listed values are P500Q reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P500Q-QL2 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical17
P500Q-QL2 has a yield strength of 545 MPa (79 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 70% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P500Q-QL2 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 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
P500Q-QL2 conducts electricity at 7.2 % IACS, worse than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of P500Q-QL2 takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability6
P500Q-QL2's machinability is fair (45/100, worse than 65% of steel grades); weldability very good (70/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P500Q-QL2
Is P500Q easy to machine?
Machines like a 200–230 HB Q&T low-alloy steel: rigid setups, coated carbide, moderate speeds; avoid heavy work hardening at the flame-cut edge.
Can P500Q be welded?
Weldable by SAW/GMAW/SMAW with low-hydrogen consumables; control CEV, preheat 100–150 °C on heavy sections and limit heat input to protect HAZ toughness and strength.
Can P500Q be formed, bent or molded?
Cold formable with bend radii of ~3×t transverse; hot forming above ~580 °C degrades the Q&T properties and requires re-quench-and-temper.
What surface finishes work on P500Q?
No anodizing; blast-and-paint, metallize or zinc-rich primer systems are standard, and phosphating works for temporary protection.
P500Q 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 | ≤ 0.18 | 0.15 |
| Si | ≤ 0.6 | 0.35 |
| Mn | 0.8 – 1.7 | 1.35 |
| P0.020 max for QL2 | ≤ 0.03 | 0.01 |
| S0.005 max for QL2 | ≤ 0.02 | 0 |
| Altotal Al, grain refining | ≥ 0.02 | 0.04 |
| Cr | ≤ 1.5 | 0.5 |
| Ni | ≤ 2 | 0.8 |
| Mo | ≤ 0.7 | 0.35 |
| Cu | ≤ 0.5 | 0.15 |
| V | ≤ 0.12 | 0.04 |
| Nb | ≤ 0.06 | 0.03 |
| Ti | ≤ 0.05 | 0.02 |
| Zr | ≤ 0.05 | — |
| B | ≤ 0.01 | 0 |
| N | ≤ 0.02 | 0.01 |
| Fe | balance | — |
P500Q-QL2 — frequently asked
What is P500Q-QL2 used for?
P500Q-QL2 is typically used for high-pressure vessels, boiler drums, heavy structural plate and mining and construction equipment. In short: 500 MPa Q&T plate class; weldable high-strength vessel steel; thinner walls than normalized plate.
What is the yield strength of P500Q-QL2?
P500Q-QL2 has a typical yield strength of 545 MPa (79 ksi) and a tensile strength of 660 MPa (95.7 ksi) — stronger than 70% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is P500Q-QL2 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines like a 200–230 HB Q&T low-alloy steel: rigid setups, coated carbide, moderate speeds; avoid heavy work hardening at the flame-cut edge.
Can P500Q-QL2 be welded?
Yes — weldability is rated very good (70/100). Weldable by SAW/GMAW/SMAW with low-hydrogen consumables; control CEV, preheat 100–150 °C on heavy sections and limit heat input to protect HAZ toughness and strength.
What surface finishes work on P500Q-QL2?
No anodizing; blast-and-paint, metallize or zinc-rich primer systems are standard, and phosphating works for temporary protection.
Can P500Q-QL2 be formed, bent or molded?
Cold formable with bend radii of ~3×t transverse; hot forming above ~580 °C degrades the Q&T properties and requires re-quench-and-temper.
What is the maximum service temperature of P500Q-QL2?
P500Q-QL2 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.
What is the difference between P500Q-QT and P500Q-SR?
QT is the default condition — standard delivery condition for plate up to ~50 mm; impact tested at 0 °C. SR: condition of fabricated vessels after PWHT; expect modest loss of yield and hardness. Yield strength is 545 MPa in QT versus 510 MPa in SR.
Sources
- EN 10028-6 Flat products made of steels for pressure purposes — Part 6: Weldable fine grain steels, quenched and tempered — CEN (2020)
- EN 10025-6 (related S500Q structural Q&T plate) — CEN (2019)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- Quenched and tempered pressure-vessel plate datasheets (Dillinger / SSAB / Voestalpine) — various mills (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.