Steel P500QL1 QT+SR
Heat-treated state
EN 1.8875
QT+SR = q&T + stress relieved / simulated PWHT
Ordered when the fabricated vessel will see PWHT; properties verified after a simulated post-weld heat treatment cycle, with a modest strength drop.
Values for the QT+SR condition
Other P500QL1 tempers and conditions
P500QL1 is listed in 4 conditions; see the grade overview at P500QL1.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Q&T | Maximum-thickness plate; used for large forgeable shells where a further strength reduction is accepted. | 480 | 610 | 19 | 13 HRC | 7.8 % IACS |
Q&T | Heavy plate for thick-wall vessels; slightly reduced strength class because of lower quench severity through thickness. | 530 | 640 | 20 | 15 HRC | 7.8 % IACS |
QT+SRThis page Q&T + stress relieved / simulated PWHT | Ordered when the fabricated vessel will see PWHT; properties verified after a simulated post-weld heat treatment cycle, with a modest strength drop. | 530 | 630 | 21 | 15 HRC | 7.8 % IACS |
QTDefault Quenched and tempered | Standard as-delivered condition for plate up to 50 mm; full 500 MPa yield class with −40 °C impact guarantee. | 560 | 660 | 20 | 18 HRC | 7.8 % IACS |
What is P500QL1 QT+SR?
P500QL1 QT+SR is P500QL1 heat treated to QT+SR — ordered when the fabricated vessel will see PWHT; properties verified after a simulated post-weld heat treatment cycle, with a modest strength drop. P500QL1 QT+SR has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 630 MPa (91.4 ksi) — stronger than 69% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi). P500QL1 QT+SR 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). QT is the default condition FabDigit quotes; QT+SR is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 160 MPa·√m (145.6 ksi·√in), better than 98% of steel grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
P500QL1 QT+SR properties
Typical room-temperature values for P500QL1 QT+SR; 23 are specific to this condition. Other listed values are P500QL1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P500QL1 QT+SR 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).
Mechanical17
P500QL1 QT+SR has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 630 MPa (91.4 ksi) — stronger than 69% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P500QL1 QT+SR is rated for continuous service to 300°C (572 °F). It conducts heat at 40 W/m·K (23.1 BTU/hr·ft·°F), worse than 64% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P500QL1 QT+SR conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of P500QL1 QT+SR takes about 26 MJ of energy and emits 2.2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 25%.
Manufacturability5
P500QL1 QT+SR's machinability is fair (48/100, worse than 57% of steel grades); weldability good (62/100); formability fair (48/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P500QL1 QT+SR
Is P500QL1 easy to machine?
Machine as a ~210 HB Q&T alloy steel: rigid setups, coated carbide, moderate speeds and generous feed; avoid overheating the surface to prevent local tempering.
Can P500QL1 be welded?
Weldable by SAW/GMAW/SMAW with low-hydrogen consumables, preheat typically 100–175 °C depending on thickness and CEV, and controlled interpass temperature and heat input to protect the −40 °C HAZ toughness.
Can P500QL1 be formed, bent or molded?
Cold form with generous bend radii (≈3–4 t) transverse to rolling direction; hot forming above the tempering temperature destroys the Q&T condition and requires full re-heat-treatment.
What surface finishes work on P500QL1?
Not corrosion resistant — shot blast to Sa 2½ and apply epoxy/zinc-rich primer or metallising; suitable for painting and thermal spray, not for anodizing.
P500QL1 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 | 0.3 |
| Mn | 0.8 – 1.7 | 1.3 |
| P | ≤ 0.02 | 0.01 |
| Slow-S for QL1 toughness | ≤ 0.01 | 0 |
| Altotal Al, grain refinement | ≥ 0.02 | 0.04 |
| Cr | ≤ 1.5 | 0.6 |
| Mo | ≤ 0.7 | 0.45 |
| Nimain low-temperature toughness element | ≤ 2 | 1.2 |
| Cu | ≤ 0.5 | 0.15 |
| Nb | ≤ 0.06 | 0.03 |
| Ti | ≤ 0.05 | 0.02 |
| V | ≤ 0.12 | 0.05 |
| B | ≤ 0.01 | 0 |
| N | ≤ 0.02 | 0.01 |
| Fe | balance | — |
P500QL1 QT+SR — frequently asked
What is P500QL1 QT+SR used for?
P500QL1 QT+SR is typically used for cryogenic vessels, LNG equipment, arctic pipeline components and low-temperature process plant. In short: −40 °C toughness class; cold-service P500Q variant; heavy welded plate grade.
What is the yield strength of P500QL1 QT+SR?
P500QL1 QT+SR has a typical yield strength of 530 MPa (76.9 ksi) and a tensile strength of 630 MPa (91.4 ksi) — stronger than 69% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is P500QL1 QT+SR easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machine as a ~210 HB Q&T alloy steel: rigid setups, coated carbide, moderate speeds and generous feed; avoid overheating the surface to prevent local tempering.
Can P500QL1 QT+SR be welded?
Yes — weldability is rated good (62/100). Weldable by SAW/GMAW/SMAW with low-hydrogen consumables, preheat typically 100–175 °C depending on thickness and CEV, and controlled interpass temperature and heat input to protect the −40 °C HAZ toughness.
What surface finishes work on P500QL1 QT+SR?
Not corrosion resistant — shot blast to Sa 2½ and apply epoxy/zinc-rich primer or metallising; suitable for painting and thermal spray, not for anodizing.
Can P500QL1 QT+SR be formed, bent or molded?
Cold form with generous bend radii (≈3–4 t) transverse to rolling direction; hot forming above the tempering temperature destroys the Q&T condition and requires full re-heat-treatment.
What is the maximum service temperature of P500QL1 QT+SR?
P500QL1 QT+SR is rated for continuous use to about 300°C (572 °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 — CEN (2015)
- EN 1011-2 Welding — Recommendations for welding of metallic materials: Arc welding of ferritic steels — CEN (2001)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
- Quenched and tempered pressure vessel plate datasheets (EN 10028-6 P355Q–P500QL2 range) — European plate mills (2022)
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.