Steel P285QH-QT (Quenched and tempered)
Heat-treated state · default condition
EN P285QH
Standard mill delivery condition for P285QH plate; use for general pressure-vessel shells, heads and boiler drums.
Values for the QT condition
Other P285QH tempers and conditions
P285QH is listed in 3 conditions; see the grade overview at P285QH.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
quenched, tempered and stress relieved / simulated PWHT | Choose when the vessel will see one or more post-weld heat treatments (typically 550–620 °C) and the purchaser requires simulated-PWHT test coupons. | 305 | 445 | 28 | 135 HB | 10 % IACS |
Normalized | Normalized plate meeting the same 285 MPa class; used for thinner plate or when the mill/purchaser prefers the normalized route (cross-order with P285NH / Q245R). | 310 | 450 | 28 | 135 HB | 10 % IACS |
QTDefaultThis page Quenched and tempered | Standard mill delivery condition for P285QH plate; use for general pressure-vessel shells, heads and boiler drums. | 320 | 460 | 27 | 140 HB | 10 % IACS |
What is P285QH-QT?
P285QH-QT is P285QH heat treated to QT — standard mill delivery condition for P285QH plate; use for general pressure-vessel shells, heads and boiler drums. P285QH-QT has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 81% of steel grades. Elongation at break is 27% and the elastic modulus is 210 GPa (30.5 Msi). P285QH-QT 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).
Advantages
- Readily welded — 90/100, better than 90% of steel grades
- Tough — resists crack growth — 130 MPa·√m (118.3 ksi·√in), better than 89% of steel grades
- Forms and bends easily — 72/100, better than 88% of steel grades
- Ductile — tolerates forming and impact — 27%, better than 86% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
- Low strength — 320 MPa (46.4 ksi), worse than 81% of steel grades
P285QH-QT properties
Typical room-temperature values for P285QH-QT; 22 are specific to this condition. Other listed values are P285QH reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P285QH-QT 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
P285QH-QT has a yield strength of 320 MPa (46.4 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 81% of steel grades. Elongation at break is 27% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P285QH-QT is rated for continuous service to 400°C (752 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P285QH-QT conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of P285QH-QT takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability6
P285QH-QT's machinability is good (60/100, better than 83% of steel grades); weldability excellent (90/100); formability very good (72/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P285QH-QT
Is P285QH easy to machine?
Machines like ordinary C-Mn plate steel (~65 % of AISI 1212); use sharp carbide tooling and generous feed to break the gummy chip, drill edge preparations without difficulty.
Can P285QH be welded?
Excellent weldability with SAW/SMAW/GMAW at CEV ≈ 0.40; use low-hydrogen consumables, preheat 50–150 °C for heavy sections and PWHT at 550–620 °C per EN 13445/AD 2000.
Can P285QH be formed, bent or molded?
Readily cold rolled into shells and cold/hot dished into heads; keep bend radius ≥ 2t cold, and re-normalize or re-QT after hot forming above ~580 °C.
What surface finishes work on P285QH?
Shot blast to Sa 2½ and paint or metallize — the steel has no inherent corrosion resistance; weld overlay or roll-bonded stainless cladding is common for aggressive process sides.
P285QH 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 | 0.14 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.6 – 1.4 | 1.1 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.01 | 0 |
| Altotal Al, fully killed / fine grain | ≥ 0.02 | 0.04 |
| Cr | ≤ 0.3 | 0.05 |
| Cu | ≤ 0.3 | 0.08 |
| Mo | ≤ 0.08 | 0.02 |
| Ni | ≤ 0.5 | 0.1 |
| Nb | ≤ 0.05 | 0.02 |
| Ti | ≤ 0.03 | 0.01 |
| V | ≤ 0.05 | 0.01 |
| N | ≤ 0.01 | 0.01 |
| Fe | balance | — |
P285QH-QT — frequently asked
What is P285QH-QT used for?
P285QH-QT is typically used for boiler drums, pressure vessel shells, heat exchangers and storage tanks. In short: quenched-and-tempered vessel plate; Q245R cross-reference; Z35 through-thickness available.
What is the yield strength of P285QH-QT?
P285QH-QT has a typical yield strength of 320 MPa (46.4 ksi) and a tensile strength of 460 MPa (66.7 ksi) — weaker than 81% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is P285QH-QT easy to machine?
Reasonably — machinability is rated good (60/100, better than 83% of steel grades). Machines like ordinary C-Mn plate steel (~65 % of AISI 1212); use sharp carbide tooling and generous feed to break the gummy chip, drill edge preparations without difficulty.
Can P285QH-QT be welded?
Yes — weldability is rated excellent (90/100). Excellent weldability with SAW/SMAW/GMAW at CEV ≈ 0.40; use low-hydrogen consumables, preheat 50–150 °C for heavy sections and PWHT at 550–620 °C per EN 13445/AD 2000.
What surface finishes work on P285QH-QT?
Shot blast to Sa 2½ and paint or metallize — the steel has no inherent corrosion resistance; weld overlay or roll-bonded stainless cladding is common for aggressive process sides.
Can P285QH-QT be formed, bent or molded?
Readily cold rolled into shells and cold/hot dished into heads; keep bend radius ≥ 2t cold, and re-normalize or re-QT after hot forming above ~580 °C.
What is the maximum service temperature of P285QH-QT?
P285QH-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.
What is the difference between P285QH-QT and P285QH-N?
QT is the default condition — standard mill delivery condition for P285QH plate; use for general pressure-vessel shells, heads and boiler drums. N: normalized plate meeting the same 285 MPa class; used for thinner plate or when the mill/purchaser prefers the normalized route (cross-order with P285NH / Q245R). Yield strength is 320 MPa in QT versus 310 MPa in N.
Sources
- EN 10028-2 Flat products made of steels for pressure purposes — Non-alloy and alloy steels with specified elevated temperature properties — CEN (2017)
- EN 10164 Steel products with improved deformation properties perpendicular to the surface — CEN (2018)
- GB/T 713 Steel plates for boilers and pressure vessels (Q245R) — SAC (2014)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- EN 13445-2/-3 Unfired pressure vessels — Materials and Design — CEN (2021)
- Mysteel / 1688 (2025)
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.