Steel P500Q-QH (P500QH)
Grade
EN 1.8873
Choose when the vessel sees elevated design temperature and guaranteed hot yield values are needed.
Values for the QH 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 |
QHThis page 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 |
P500QL2 | Highest toughness sub-grade for cryogenic-leaning service and heavy restraint welds. | 545 | 660 | 21 | 18 HRC | 7.2 % IACS |
What is P500Q-QH?
P500Q-QH is P500Q in the QH grade — choose when the vessel sees elevated design temperature and guaranteed hot yield values are needed. P500Q-QH 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 20% and the elastic modulus is 210 GPa (30.5 Msi). P500Q-QH 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; QH is available on request or by drawing note.
P500Q-QH properties
Typical room-temperature values for P500Q-QH; 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-QH 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-QH 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 20% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P500Q-QH 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-QH 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-QH 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-QH'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-QH
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-QH — frequently asked
What is P500Q-QH used for?
P500Q-QH 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-QH?
P500Q-QH 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-QH 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-QH 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-QH?
No anodizing; blast-and-paint, metallize or zinc-rich primer systems are standard, and phosphating works for temporary protection.
Can P500Q-QH 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-QH?
P500Q-QH 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.