Steel P460Q-QT (Quenched and tempered)
Heat-treated state · default condition
EN 1.8870
Standard EN 10028-6 delivery condition for plate up to 50 mm — full 460 MPa yield and 40 J at 0 °C.
Values for the QT condition
Other P460Q tempers and conditions
P460Q is listed in 4 conditions; see the grade overview at P460Q.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
QT | Thickest standard class; lowest guaranteed yield (400 MPa) due to reduced quench severity at mid-thickness. | 450 | 580 | 20 | 12 HRC | 7.8 % IACS |
QT | Heavier plate class: mass-effect reduces the guaranteed yield to 440 MPa. | 490 | 600 | 21 | 14 HRC | 7.8 % IACS |
quenched, tempered and stress-relieved / simulated PWHT | Choose when the vessel will see post-weld heat treatment; properties are certified after a simulated PWHT cycle, with a modest strength drop. | 490 | 595 | 22 | 11 HRC | 7.8 % IACS |
QTDefaultThis page Quenched and tempered | Standard EN 10028-6 delivery condition for plate up to 50 mm — full 460 MPa yield and 40 J at 0 °C. | 510 | 620 | 21 | 200 HB | — |
What is P460Q-QT?
P460Q-QT is P460Q heat treated to QT — standard EN 10028-6 delivery condition for plate up to 50 mm — full 460 MPa yield and 40 J at 0 °C. P460Q-QT has a yield strength of 510 MPa (74 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 65% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi). P460Q-QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Advantages
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- Readily welded — 72/100, better than 75% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
P460Q-QT properties
Typical room-temperature values for P460Q-QT; 11 are specific to this condition. Other listed values are P460Q reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P460Q-QT has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
P460Q-QT has a yield strength of 510 MPa (74 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 65% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P460Q-QT is rated for continuous service to 400°C (752 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical2
P460Q-QT has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental3
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of P460Q-QT takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 25%.
Manufacturability7
P460Q-QT's machinability is fair (50/100, worse than 53% of steel grades); weldability very good (72/100); formability fair (45/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P460Q-QT
Is P460Q easy to machine?
Machines like a 200 HB Q&T low-alloy steel — carbide tooling, moderate speeds, rigid setups; avoid overheating that could locally temper the plate.
Can P460Q be welded?
Readily welded by SAW/FCAW/GMAW with low-hydrogen matching consumables; preheat 100–150 °C for heavier sections, control interpass ≤250 °C and limit heat input to protect HAZ toughness.
Can P460Q be formed, bent or molded?
Cold-bend with inner radius ≥3t (transverse) and generous die openings; hot forming above the tempering temperature requires re-quench and temper to restore properties.
What surface finishes work on P460Q?
No inherent corrosion resistance — shot-blast to Sa 2½ and apply epoxy/zinc-rich primer, metallize, or use stainless weld overlay for wet service.
P460Q 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 | ≤ 0.2 | 0.16 |
| Si | ≤ 0.6 | 0.35 |
| Mn | 0.9 – 1.7 | 1.4 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Cr | ≤ 1.5 | 0.4 |
| Nimain toughness contributor | ≤ 2 | 0.7 |
| Mo | ≤ 0.7 | 0.25 |
| Cu | ≤ 0.5 | 0.15 |
| V | ≤ 0.12 | 0.04 |
| Nbgrain refiner | ≤ 0.06 | 0.03 |
| Ti | ≤ 0.05 | 0.02 |
| Altotal Al, fine-grain practice | ≥ 0.02 | 0.04 |
| Bhardenability | ≤ 0.01 | 0 |
| Zr | ≤ 0.05 | — |
| N | ≤ 0.02 | 0.01 |
| Fe | balance | — |
P460Q-QT — frequently asked
What is P460Q-QT used for?
P460Q-QT is typically used for pressure vessels, boiler and tank plate, offshore structures and heavy welded fabrications. In short: weldable 460 MPa plate; good low-temperature toughness; pressure-vessel Q&T grade.
What is the yield strength of P460Q-QT?
P460Q-QT has a typical yield strength of 510 MPa (74 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 65% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is P460Q-QT easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 53% of steel grades). Machines like a 200 HB Q&T low-alloy steel — carbide tooling, moderate speeds, rigid setups; avoid overheating that could locally temper the plate.
Can P460Q-QT be welded?
Yes — weldability is rated very good (72/100). Readily welded by SAW/FCAW/GMAW with low-hydrogen matching consumables; preheat 100–150 °C for heavier sections, control interpass ≤250 °C and limit heat input to protect HAZ toughness.
What surface finishes work on P460Q-QT?
No inherent corrosion resistance — shot-blast to Sa 2½ and apply epoxy/zinc-rich primer, metallize, or use stainless weld overlay for wet service.
Can P460Q-QT be formed, bent or molded?
Cold-bend with inner radius ≥3t (transverse) and generous die openings; hot forming above the tempering temperature requires re-quench and temper to restore properties.
What is the maximum service temperature of P460Q-QT?
P460Q-QT 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.
Sources
- EN 10028-6 — Flat products made of steels for pressure purposes, Part 6: Weldable fine grain steels, quenched and tempered — CEN (2020)
- EN 10027-2 — Designation systems for steels: steel numbers (1.8870) — CEN (2015)
- EN 13445-3 — Unfired pressure vessels: Design (physical/design data for ferritic steels) — CEN (2021)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Quenched and tempered pressure-vessel plate datasheets (P355Q–P690Q family) — European plate 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.