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Steel P500QL1 QT-50-100

Heat-treated state

EN 1.8875

QT-50-100 = q&T

Heavy plate for thick-wall vessels; slightly reduced strength class because of lower quench severity through thickness.

Budget cost $

Values for the QT-50-100 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 datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Q&T
Maximum-thickness plate; used for large forgeable shells where a further strength reduction is accepted.4806101913 HRC7.8 % IACS
QT-50-100This page
Q&T
Heavy plate for thick-wall vessels; slightly reduced strength class because of lower quench severity through thickness.5306402015 HRC7.8 % IACS
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.5306302115 HRC7.8 % 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.5606602018 HRC7.8 % IACS

What is P500QL1 QT-50-100?

P500QL1 QT-50-100 is P500QL1 heat treated to QT-50-100 — heavy plate for thick-wall vessels; slightly reduced strength class because of lower quench severity through thickness. P500QL1 QT-50-100 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 69% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi). P500QL1 QT-50-100 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-50-100 is available on request or by drawing note.

Advantages

  • Tough — resists crack growth — 145 MPa·√m (132 ksi·√in), better than 95% of steel grades

Limitations

  • Limited service temperature — 300°C (572 °F), worse than 78% of steel grades

P500QL1 QT-50-100 properties

Typical room-temperature values for P500QL1 QT-50-100; 24 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-50-100 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).

Density7.85 g/cm³0.28 lb/in³
Melting Point (Solidus)1,460°C2,660 °F
Liquidus Temperature1,510°C2,750 °F

Mechanical17

P500QL1 QT-50-100 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 69% of steel grades. Elongation at break is 20% and the elastic modulus is 210 GPa (30.5 Msi).

Elastic (Young's) Modulus210 GPa30.5 Msi
Shear Modulus81 GPa11.7 Msi
Bulk Modulus160 GPa23.2 Msi
Poisson's Ratio0.3
Tensile Strength (Ultimate)640 MPa92.8 ksi
Yield Strength (0.2% offset)530 MPa76.9 ksi
Elongation at Break20%
Reduction in Area58%
Compressive Strength530 MPa76.9 ksi
Shear Strength385 MPa55.8 ksi
Fatigue Strength (Endurance Limit)290 MPa42.1 ksi
Fracture Toughness (K_IC)145 MPa·√m132 ksi·√in
Charpy V-Notch Impact (RT)130 J95.9 ft·lbf
Hardness, Brinell200 HB
Hardness, Rockwell B93 HRB
Hardness, Rockwell C15 HRC
Hardness, Vickers210 HV

Thermal6

P500QL1 QT-50-100 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).

Thermal Conductivity40 W/m·K23.1 BTU/hr·ft·°F
Specific Heat Capacity460 J/kg·K0.11 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)12 µm/m·K6.7 µin/in·°F
Latent Heat of Fusion270 J/g116 BTU/lb
Max Service Temperature (continuous)300°C572 °F
Min Service Temperature-40°C-40 °F

Electrical3

P500QL1 QT-50-100 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.

Electrical Conductivity7.8 % IACS
Electrical Resistivity2.2×10⁻⁷ Ω·m8.66 µΩ·in
Magnetic Responseferromagnetic

Chemical & Environmental2

Corrosion resistance is not recommended (14/100), better than 70% of steel grades.

Corrosion ResistanceNot recommended14/100
Chemical Resistance SummaryRusts freely in humid air and water; needs paint, metallising or a corrosion allowance. Suitable for dry hydrocarbons and gases; avoid wet H2S service unless supplied to NACE MR0175 hardness limits.

Sustainability4

Producing a kilogram of P500QL1 QT-50-100 takes about 26 MJ of energy and emits 2.2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 25%.

Embodied Energy (primary production)26 MJ/kg11,178 BTU/lb
Embodied Carbon (primary production)2.2 kg CO₂/kg
Embodied Water45 L/kg5.4 gal/lb
Typical Recycled Content25%

Manufacturability5

P500QL1 QT-50-100's machinability is fair (46/100, worse than 59% of steel grades); weldability good (58/100); formability fair (42/100).

MachinabilityFair46/100
Machinability Rating (AISI 1212 = 100 %)57%
WeldabilityGood58/100
Formability (cold)Fair42/100
PolishabilityFair50/100

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with P500QL1 QT-50-100

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.

ElementSpec limit (wt %)Nominal
Cladle analysis≤ 0.20.16
Si≤ 0.60.3
Mn0.8 – 1.71.3
P≤ 0.020.01
Slow-S for QL1 toughness≤ 0.010
Altotal Al, grain refinement≥ 0.020.04
Cr≤ 1.50.6
Mo≤ 0.70.45
Nimain low-temperature toughness element≤ 21.2
Cu≤ 0.50.15
Nb≤ 0.060.03
Ti≤ 0.050.02
V≤ 0.120.05
B≤ 0.010
N≤ 0.020.01
Febalance—

P500QL1 QT-50-100 — frequently asked

What is P500QL1 QT-50-100 used for?

P500QL1 QT-50-100 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-50-100?

P500QL1 QT-50-100 has a typical yield strength of 530 MPa (76.9 ksi) and a tensile strength of 640 MPa (92.8 ksi) — stronger than 69% of steel grades. Strength varies by condition: see the 4 listed tempers.

Is P500QL1 QT-50-100 easy to machine?

Reasonably — machinability is rated fair (46/100, worse than 59% 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-50-100 be welded?

Yes — weldability is rated good (58/100). 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-50-100?

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-50-100 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-50-100?

P500QL1 QT-50-100 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

  1. EN 10028-6 Flat products made of steels for pressure purposes — Part 6: Weldable fine grain steels, quenched and tempered — CEN (2020)
  2. EN 10027-2 Designation systems for steels — Steel numbers — CEN (2015)
  3. EN 1011-2 Welding — Recommendations for welding of metallic materials: Arc welding of ferritic steels — CEN (2001)
  4. ASM Handbook Vol.1: Properties and Selection — Irons, Steels and High-Performance Alloys — ASM International (1990)
  5. 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.