Steel P355ML1 M-63-80
Heat-treated state
EN 1.8832, 10028-6
Upper thickness limit of the TM route; choose only where a Q&T grade (P355QL1) is not required.
Values for the M-63-80 condition
Other P355ML1 tempers and conditions
P355ML1 is listed in 5 conditions; see the grade overview at P355ML1.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
M-63-80This page M | Upper thickness limit of the TM route; choose only where a Q&T grade (P355QL1) is not required. | 370 | 500 | 25 | 152 HB | 9 % IACS |
M | Heavy plate for thick-wall vessels and nozzle reinforcement; slightly lower guaranteed strength and toughness scatter. | 380 | 510 | 26 | 155 HB | 9 % IACS |
Stress relieved | Order this option when the vessel will be PWHT'd: properties are verified on simulated-PWHT samples, with a small loss of strength and Charpy energy. | 380 | 505 | 29 | 152 HB | 9 % IACS |
M | Medium-thickness shell and head plate; yield minimum drops one step with thickness. | 390 | 515 | 27 | 158 HB | 9 % IACS |
MDefault Thermomechanically controlled processed | Standard as-delivered thermomechanically rolled plate for the thinnest and most-stocked thickness class; full 355 MPa yield with −40 °C impact guarantee. | 400 | 520 | 28 | 160 HB | 9 % IACS |
What is P355ML1 M-63-80?
P355ML1 M-63-80 is P355ML1 heat treated to M-63-80 — upper thickness limit of the TM route; choose only where a Q&T grade (P355QL1) is not required. P355ML1 M-63-80 has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 70% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi). P355ML1 M-63-80 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). M is the default condition FabDigit quotes; M-63-80 is available on request or by drawing note.
Advantages
- Easy to machine — 62/100, better than 89% of steel grades
- Readily welded — 86/100, better than 85% of steel grades
- Forms and bends easily — 66/100, better than 83% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
- Tough — resists crack growth — 115 MPa·√m (104.7 ksi·√in), better than 77% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
P355ML1 M-63-80 properties
Typical room-temperature values for P355ML1 M-63-80; 22 are specific to this condition. Other listed values are P355ML1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
P355ML1 M-63-80 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
P355ML1 M-63-80 has a yield strength of 370 MPa (53.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 70% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
P355ML1 M-63-80 is rated for continuous service to 400°C (752 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
P355ML1 M-63-80 conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of P355ML1 M-63-80 takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
P355ML1 M-63-80's machinability is good (62/100, better than 89% of steel grades); weldability excellent (86/100); formability good (66/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with P355ML1 M-63-80
Is P355ML1 easy to machine?
Machines like normalized C-Mn plate at ~65 % of AISI 1212; sticky chips, use positive-rake carbide, moderate speed and generous coolant to avoid built-up edge.
Can P355ML1 be welded?
Excellent weldability with low CEV — SAW/GMAW/SMAW with basic, low-hydrogen consumables matching −40 °C toughness; keep heat input and interpass temperature controlled (typically ≤ 250 °C) so the thermomechanical fine grain and HAZ toughness are preserved.
Can P355ML1 be formed, bent or molded?
Good cold formability for rolling shells and pressing heads; hot forming above ~580 °C or normalizing destroys the TM condition and requires re-qualification (or use of the Q&T grade P355QL1).
What surface finishes work on P355ML1?
No anodizing; shot-blast to Sa 2½ and apply epoxy/zinc-rich paint, metallize or thermal-spray; hot-dip galvanizing possible but check embrittlement and coating temperature effects.
P355ML1 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 |
|---|---|---|
| Ccast analysis limit | ≤ 0.16 | 0.1 |
| Si | ≤ 0.5 | 0.3 |
| Mn | 1 – 1.7 | 1.4 |
| P | ≤ 0.03 | 0.01 |
| Slower S usually supplied for low-temperature toughness / Z quality | ≤ 0.02 | 0.01 |
| Altotal Al, grain refinement | ≥ 0.02 | 0.04 |
| N | ≤ 0.02 | 0.01 |
| Nbmicroalloy; Nb+V+Ti ≤ 0.22 | ≤ 0.05 | 0.03 |
| V | ≤ 0.1 | 0.04 |
| Ti | ≤ 0.05 | 0.02 |
| Crresidual | ≤ 0.3 | 0.05 |
| Niaids low-temperature toughness | ≤ 0.5 | 0.15 |
| Curesidual | ≤ 0.3 | 0.1 |
| Moresidual | ≤ 0.1 | 0.02 |
| FeCEV (IIW) typically ≤ 0.43 % | balance | — |
P355ML1 M-63-80 — frequently asked
What is P355ML1 M-63-80 used for?
P355ML1 M-63-80 is typically used for low-temperature vessels, gas storage tanks and chemical process equipment. In short: weldable -40 °C vessel plate; high 28 % elongation; lower-strength ML1 workhorse.
What is the yield strength of P355ML1 M-63-80?
P355ML1 M-63-80 has a typical yield strength of 370 MPa (53.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 70% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is P355ML1 M-63-80 easy to machine?
Reasonably — machinability is rated good (62/100, better than 89% of steel grades). Machines like normalized C-Mn plate at ~65 % of AISI 1212; sticky chips, use positive-rake carbide, moderate speed and generous coolant to avoid built-up edge.
Can P355ML1 M-63-80 be welded?
Yes — weldability is rated excellent (86/100). Excellent weldability with low CEV — SAW/GMAW/SMAW with basic, low-hydrogen consumables matching −40 °C toughness; keep heat input and interpass temperature controlled (typically ≤ 250 °C) so the thermomechanical fine grain and HAZ toughness are preserved.
What surface finishes work on P355ML1 M-63-80?
No anodizing; shot-blast to Sa 2½ and apply epoxy/zinc-rich paint, metallize or thermal-spray; hot-dip galvanizing possible but check embrittlement and coating temperature effects.
Can P355ML1 M-63-80 be formed, bent or molded?
Good cold formability for rolling shells and pressing heads; hot forming above ~580 °C or normalizing destroys the TM condition and requires re-qualification (or use of the Q&T grade P355QL1).
What is the maximum service temperature of P355ML1 M-63-80?
P355ML1 M-63-80 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 P355ML1-M and P355ML1 M-63-80?
M is the default condition — standard as-delivered thermomechanically rolled plate for the thinnest and most-stocked thickness class; full 355 MPa yield with −40 °C impact guarantee. M-63-80: upper thickness limit of the TM route; choose only where a Q&T grade (P355QL1) is not required. Yield strength is 400 MPa in M versus 370 MPa in M-63-80.
Sources
- EN 10028-5 — Flat products made of steels for pressure purposes, Part 5: Weldable fine grain steels, thermomechanically rolled — CEN (2017)
- EN 10164 — Steel products with improved deformation properties perpendicular to the surface — CEN (2018)
- EN 10027-2 — Designation systems for steels: Numerical system (1.8832) — CEN (2015)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Thermomechanically rolled pressure vessel plate (P355M/ML1/ML2) datasheets — European plate mills (e.g. Dillinger, Voestalpine, SSAB) (2022)
- (16MnDR/P355ML1) — 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.