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Steel P91 Normalized vs P91 Q&T

Steel · P91 temper comparison

P91 Normalized and P91 Q&T are two conditions of the same steel grade, P91: Normalized versus Q&T (quenched and tempered). The chemistry is identical, so every difference below comes from the condition. P91 Normalized is the stronger of the two: yield strength 950 MPa (138 ksi) against 520 MPa (75.4 ksi) for P91 Q&T, about 83% more; tensile strength follows at 1,300 MPa (189 ksi) vs 670 MPa (97.2 ksi). In exchange, P91 Q&T is the more ductile: elongation 22% versus 10% for P91 Normalized, and P91 Normalized is harder (420 HB vs 225 HB). P91 Q&T runs hotter in service (600°C vs 200°C continuous). On the shop floor, P91 Q&T machines more easily (fair vs poor).

P91 NormalizedChoose it when strength drives the design.

P91 Q&TChoose it when the part is bent, formed or impact-loaded, or when the part sees heat.

P91 Normalized vs P91 Q&T: properties

P91 NormalizedP91 Q&T

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

1,300 MPa189 ksi
670 MPa97.2 ksi

Yield Strength (0.2% offset)

950 MPa138 ksi
520 MPa75.4 ksi

Elongation at Break

10%
22%

Reduction in Area

45%
60%

Charpy V-Notch Impact (RT)

12 J8.9 ft·lbf
130 J95.9 ft·lbf

Hardness, Brinell

420 HB
225 HB

Hardness, Rockwell C

45 HRC
20 HRC

Hardness, Vickers

440 HV
235 HV

Same in both: Elastic (Young's) Modulus 218 GPa31.6 Msi · Shear Modulus 84 GPa12.2 Msi · Bulk Modulus 170 GPa24.7 Msi · Poisson's Ratio 0.3 · Compressive Strength 770 MPa112 ksi · Shear Strength 600 MPa87 ksi · Fatigue Strength (Endurance Limit) 430 MPa62.4 ksi · Fracture Toughness (K_IC) 40 MPa·√m36.4 ksi·√in · Hardness, Rockwell B 96 HRB

Physical

Density and transition temperatures.

Same in both: Density 7.77 g/cm³0.28 lb/in³ · Melting Point (Solidus) 1,450°C2,642 °F · Liquidus Temperature 1,500°C2,732 °F

Thermal

How each material carries heat and how hot it can run.

Max Service Temperature (continuous)

200°C392 °F
600°C1,112 °F

Same in both: Thermal Conductivity 25 W/m·K14.4 BTU/hr·ft·°F · Specific Heat Capacity 480 J/kg·K0.11 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 10.9 µm/m·K6.1 µin/in·°F · Latent Heat of Fusion 250 J/g107 BTU/lb · Min Service Temperature -30°C-22 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 2.7 % IACS · Electrical Resistivity 6.4×10⁻⁷ Ω·m25.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Corrosion Resistance 28 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

15 / 100
38 / 100

Weldability

20 / 100
15 / 100

Formability (cold)

10 / 100
20 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 25% · Brazeability / Solderability 30 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Same in both: Embodied Energy (primary production) 34 MJ/kg14,617 BTU/lb · Embodied Carbon (primary production) 2.5 kg CO₂/kg · Embodied Water 70 L/kg8.4 gal/lb · Typical Recycled Content 30%

Strength versus weight

Yield strength against density for every steel grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

2005001,0002,0007.588.5Density (g/cm³)Yield strength (MPa) — log scaleP91

P91 Normalized vs P91 Q&T — frequently asked

Is P91 Normalized stronger than P91 Q&T?

Yes. P91 Normalized has a typical yield strength of 950 MPa (138 ksi) against 520 MPa (75.4 ksi) for P91 Q&T — about 83% more. Tensile strength is 1,300 MPa (189 ksi) vs 670 MPa (97.2 ksi).

Which condition does FabDigit quote by default, Normalized or Q&T?

HR is the default P91 condition in the FabDigit quote flow (neither Normalized nor Q&T). The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.

Which is easier to machine, P91 Normalized or P91 Q&T?

P91 Q&T. Its machinability rates fair (38/100) against poor (15/100) for P91 Normalized; for welding the order is P91 Normalized first (poor, 20/100) then P91 Q&T (poor, 15/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in P91 Normalized and P91 Q&T side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.