Steel P275NL1 N+HIC
Certified grade
EN 1.0488, 10028-3
N+HIC = n + HIC/SSC tested
Low-S, calcium-treated melt with NACE TM0284 HIC testing for wet H2S separators and knock-out drums.
Values for the N+HIC condition
Other P275NL1 tempers and conditions
P275NL1 is listed in 9 conditions; see the grade overview at P275NL1.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
N | Maximum thickness covered by EN 10028-3; specify centre-of-thickness impact testing. | 250 | 410 | 26 | 128 HB | 10.8 % IACS |
N | Very heavy sections where through-thickness normalizing response limits strength. | 260 | 415 | 26 | 130 HB | 10.8 % IACS |
N | Thick plate for nozzles/forged-equivalent sections; tensile band drops to 370–490 MPa. | 270 | 425 | 27 | 132 HB | 10.8 % IACS |
N | Heavy shell plate and tubesheet blanks; 255 MPa minimum yield. | 290 | 440 | 27 | 136 HB | 10.8 % IACS |
Normalized then stress relieved / simulated PWHT | Order when the fabricated vessel will see PWHT; properties verified after simulated heat-treatment cycles. | 295 | 440 | 29 | 135 HB | 10.8 % IACS |
N | Medium plate for vessel shells and heads; yield derated to 265 MPa minimum. | 300 | 445 | 28 | 138 HB | 10.8 % IACS |
N+HICThis page N + HIC/SSC tested | Low-S, calcium-treated melt with NACE TM0284 HIC testing for wet H2S separators and knock-out drums. | 305 | 445 | 28 | 135 HB | 10.8 % IACS |
NDefault Normalized | Standard stocked condition for thin plate and shell courses; full 275 MPa yield with −40 °C impact guarantee. | 310 | 450 | 28 | 140 HB | 10.8 % IACS |
normalized with through-thickness (Z-quality) ductility per EN 10164 | Pick for nozzle-to-shell or T-joint welds loaded in the thickness direction to avoid lamellar tearing. | 310 | 450 | 28 | 140 HB | 10.8 % IACS |
What is P275NL1 N+HIC?
P275NL1 N+HIC is P275NL1 in a N+HIC certified grade — low-S, calcium-treated melt with NACE TM0284 HIC testing for wet H2S separators and knock-out drums. P275NL1 N+HIC has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 445 MPa (64.5 ksi) — weaker than 84% of steel grades. Elongation at break is 28% and the elastic modulus is 210 GPa (30.5 Msi). P275NL1 N+HIC 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). N is the default condition FabDigit quotes; N+HIC is available on request or by drawing note.
Advantages
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Ductile — tolerates forming and impact — 28%, better than 89% of steel grades
- Easy to machine — 62/100, better than 89% of steel grades
- Forms and bends easily — 72/100, better than 88% of steel grades
- Readily welded — 88/100, better than 87% of steel grades
Limitations
- Low strength — 305 MPa (44.2 ksi), worse than 84% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
P275NL1 N+HIC properties
Typical room-temperature values for P275NL1 N+HIC; 22 are specific to this condition. Other listed values are P275NL1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P275NL1 N+HIC 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
P275NL1 N+HIC has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 445 MPa (64.5 ksi) — weaker than 84% of steel grades. Elongation at break is 28% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P275NL1 N+HIC is rated for continuous service to 400°C (752 °F). It conducts heat at 49 W/m·K (28.3 BTU/hr·ft·°F), better than 83% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P275NL1 N+HIC conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (14/100), better than 70% of steel grades.
Sustainability4
Producing a kilogram of P275NL1 N+HIC takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
P275NL1 N+HIC's machinability is good (62/100, better than 89% of steel grades); weldability excellent (88/100); formability very good (72/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P275NL1 N+HIC
Is P275NL1 easy to machine?
Machines like normalized C-Mn steel (~65 % of AISI 1212); use sharp positive-rake carbide, moderate speeds, and expect gummy chips at low hardness.
Can P275NL1 be welded?
Excellent weldability with CEV ≤ 0.40 — SAW/SMAW/GMAW with low-hydrogen consumables; preheat 100–150 °C for thick sections and control heat input to protect the −40 °C toughness.
Can P275NL1 be formed, bent or molded?
Cold-rolls and dishes readily; hot forming above 950 °C requires re-normalizing, and heavy cold strains (>5 %) should be followed by normalizing or stress relief per EN 13445-4.
What surface finishes work on P275NL1?
No anodizing; shot-blast to Sa 2½ then epoxy/zinc primer, hot-dip galvanize or metallize — bare surfaces rust quickly in humid or marine air.
P275NL1 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, t ≤ 30 mm | ≤ 0.16 | 0.13 |
| Si | ≤ 0.4 | 0.3 |
| Mn | 0.5 – 1.4 | 1.1 |
| Ptighter than P275NH | ≤ 0.03 | 0.01 |
| Stighter than P275NH | ≤ 0.02 | 0.01 |
| Altotal Al, grain refining | ≥ 0.02 | 0.04 |
| N | ≤ 0.02 | 0.01 |
| Cr | ≤ 0.3 | 0.08 |
| Cu | ≤ 0.3 | 0.1 |
| Ni | ≤ 0.5 | 0.15 |
| Mo | ≤ 0.08 | 0.02 |
| NbNb+Ti+V ≤ 0.05 combined limit applies | ≤ 0.05 | 0.02 |
| Ti | ≤ 0.03 | 0.01 |
| V | ≤ 0.05 | 0.01 |
| Fe | balance | — |
P275NL1 N+HIC — frequently asked
What is P275NL1 N+HIC used for?
P275NL1 N+HIC is typically used for low-temperature pressure vessels, cryogenic piping, offshore equipment and gas storage tanks. In short: cold-service P275 variant; impact-tested to −40 °C; A333 Grade 6 counterpart.
What is the yield strength of P275NL1 N+HIC?
P275NL1 N+HIC has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 445 MPa (64.5 ksi) — weaker than 84% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is P275NL1 N+HIC easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like normalized C-Mn steel (~65 % of AISI 1212); use sharp positive-rake carbide, moderate speeds, and expect gummy chips at low hardness.
Can P275NL1 N+HIC be welded?
Yes — weldability is rated excellent (88/100). Excellent weldability with CEV ≤ 0.40 — SAW/SMAW/GMAW with low-hydrogen consumables; preheat 100–150 °C for thick sections and control heat input to protect the −40 °C toughness.
What surface finishes work on P275NL1 N+HIC?
No anodizing; shot-blast to Sa 2½ then epoxy/zinc primer, hot-dip galvanize or metallize — bare surfaces rust quickly in humid or marine air.
Can P275NL1 N+HIC be formed, bent or molded?
Cold-rolls and dishes readily; hot forming above 950 °C requires re-normalizing, and heavy cold strains (>5 %) should be followed by normalizing or stress relief per EN 13445-4.
What is the maximum service temperature of P275NL1 N+HIC?
P275NL1 N+HIC 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 P275NL1-N and P275NL1 N-40-60?
N is the default condition — standard stocked condition for thin plate and shell courses; full 275 MPa yield with −40 °C impact guarantee. N-40-60: heavy shell plate and tubesheet blanks; 255 MPa minimum yield. Yield strength is 310 MPa in N versus 290 MPa in N-40-60.
Sources
- EN 10028-3 Flat products made of steels for pressure purposes — Weldable fine grain steels, normalized — CEN (2017)
- EN 10164 Steel products with improved deformation properties perpendicular to the surface — CEN (2018)
- ASTM A333/A333M Grade 6 (low-temperature service pipe, comparable properties) — ASTM (2018)
- GB 3531 (16MnDR, domestic counterpart) — SAC (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- EN 13445-3 Unfired pressure vessels — Design — CEN (2021)
- worldsteel LCI data for steel plate — World Steel Association (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.