Steel Q355NH TMCP
Supply condition
TMCP = thermomechanically controlled processed
Pick when a lower carbon equivalent and better field weldability are needed at the same strength level.
Values for the TMCP condition
Other Q355NH tempers and conditions
Q355NH is listed in 7 conditions; see the grade overview at Q355NH.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HRDefault Hot rolled | Default stocked condition for weathering plate, coil and sections up to about 40 mm. | 380 | 540 | 26 | 165 HB | — |
Quality grade C | Standard toughness class for general outdoor structures in temperate climates. | 380 | 540 | 26 | 165 HB | 8 % IACS |
Quality grade D | For rolling stock and bridges exposed to cold winters. | 385 | 545 | 26 | 167 HB | 8 % IACS |
Normalized | Choose for thicker plate or where uniform fine grain and guaranteed low-temperature impact energy are required. | 390 | 545 | 28 | 160 HB | 8 % IACS |
Quality grade E | Lowest-temperature class, for northern-China railway wagons and cold-region structures. | 395 | 550 | 27 | 170 HB | 8 % IACS |
TMCPThis page Thermomechanically controlled processed | Pick when a lower carbon equivalent and better field weldability are needed at the same strength level. | 410 | 550 | 27 | 170 HB | 8 % IACS |
Cold rolled | Thin gauge weathering strip for container panels and formed profiles; higher strength, reduced ductility. | 480 | 600 | 18 | 190 HB | 8 % IACS |
What is Q355NH TMCP?
Q355NH TMCP is Q355NH supplied in the TMCP condition — pick when a lower carbon equivalent and better field weldability are needed at the same strength level. Q355NH TMCP has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 57% of steel grades. Elongation at break is 27% and the elastic modulus is 206 GPa (29.9 Msi). Q355NH TMCP has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; TMCP is available on request or by drawing note.
Advantages
- Good corrosion resistance — 32/100, better than 96% of steel grades
- Tough — resists crack growth — 140 MPa·√m (127.4 ksi·√in), better than 94% 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
- Ductile — tolerates forming and impact — 27%, better than 86% of steel grades
Limitations
- Hard to polish — 45/100, worse than 84% of steel grades
Q355NH TMCP properties
Typical room-temperature values for Q355NH TMCP; 23 are specific to this condition. Other listed values are Q355NH reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
Q355NH TMCP has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
Q355NH TMCP has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 57% of steel grades. Elongation at break is 27% and the elastic modulus is 206 GPa (29.9 Msi).
Thermal6
Q355NH TMCP is rated for continuous service to 380°C (716 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 12 µm/m·K (6.67 µin/in·°F).
Electrical3
Q355NH TMCP conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), better than 96% of steel grades.
Sustainability4
Producing a kilogram of Q355NH TMCP takes about 25 MJ of energy and emits 2.1 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
Q355NH TMCP's machinability is fair (54/100, better than 54% 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 Q355NH TMCP
Is Q355NH easy to machine?
Machines like 1020-class HSLA at ~60 % of AISI 1212; use rigid setups and positive-rake carbide, expect stringy chips from low-sulfur heats.
Can Q355NH be welded?
Readily welded by SMAW/GMAW/SAW with low-hydrogen consumables; use weathering-matched filler (e.g. E8018-W2 / ER80S-Ni1 type) so the joint patinas with the base metal, preheat 50–100 °C above ~30 mm.
Can Q355NH be formed, bent or molded?
Cold bends to 2a–3a radius across the rolling direction; hot forming 900–1050 °C followed by normalizing restores toughness.
What surface finishes work on Q355NH?
Usually left bare to develop the protective rust patina (allow free-draining details and shot-blast to remove mill scale); can be painted or hot-dip galvanized where run-off staining or chlorides are an issue.
Q355NH 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 |
|---|---|---|
| Clower C (≤0.12) common in TMCP/weld-critical heats | ≤ 0.16 | 0.12 |
| Si | 0.1 – 0.5 | 0.35 |
| Mn | 0.5 – 1.5 | 1.1 |
| P | ≤ 0.03 | 0.02 |
| S | ≤ 0.03 | 0.01 |
| Cukey patina former | 0.2 – 0.55 | 0.35 |
| Cr | 0.3 – 1.25 | 0.6 |
| Ni | ≤ 0.65 | 0.25 |
| Mooptional | ≤ 0.3 | 0.05 |
| Nbmicro-alloy, optional | 0.02 – 0.06 | 0.03 |
| Vmicro-alloy, optional | 0.02 – 0.12 | 0.05 |
| Timicro-alloy, optional | 0.02 – 0.1 | 0.03 |
| Alacid-soluble Al minimum | ≥ 0.02 | 0.03 |
| Fe | balance | — |
Q355NH TMCP — frequently asked
What is Q355NH TMCP used for?
Q355NH TMCP is typically used for railway wagons, outdoor towers and container structures. In short: weldable weathering structural steel; A588 / S355J2W equivalent; paint-free outdoor service.
What is the yield strength of Q355NH TMCP?
Q355NH TMCP has a typical yield strength of 410 MPa (59.5 ksi) and a tensile strength of 550 MPa (79.8 ksi) — weaker than 57% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is Q355NH TMCP easy to machine?
Reasonably — machinability is rated fair (54/100, better than 54% of steel grades). Machines like 1020-class HSLA at ~60 % of AISI 1212; use rigid setups and positive-rake carbide, expect stringy chips from low-sulfur heats.
Can Q355NH TMCP be welded?
Yes — weldability is rated excellent (88/100). Readily welded by SMAW/GMAW/SAW with low-hydrogen consumables; use weathering-matched filler (e.g. E8018-W2 / ER80S-Ni1 type) so the joint patinas with the base metal, preheat 50–100 °C above ~30 mm.
What surface finishes work on Q355NH TMCP?
Usually left bare to develop the protective rust patina (allow free-draining details and shot-blast to remove mill scale); can be painted or hot-dip galvanized where run-off staining or chlorides are an issue.
Can Q355NH TMCP be formed, bent or molded?
Cold bends to 2a–3a radius across the rolling direction; hot forming 900–1050 °C followed by normalizing restores toughness.
What is the maximum service temperature of Q355NH TMCP?
Q355NH TMCP is rated for continuous use to about 380°C (716 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Q355NH-HR and Q355NH-CR?
HR is the default condition — default stocked condition for weathering plate, coil and sections up to about 40 mm. CR: thin gauge weathering strip for container panels and formed profiles; higher strength, reduced ductility. Yield strength is 380 MPa in HR versus 480 MPa in CR.
Sources
- GB/T 4171 Atmospheric corrosion resisting structural steel — SAC (China) (2008)
- ASTM A588/A588M High-Strength Low-Alloy Structural Steel with Atmospheric Corrosion Resistance — ASTM (2019)
- EN 10025-5 Structural steels with improved atmospheric corrosion resistance (S355J2W) — CEN (2019)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13 — Corrosion — ASM International (2005)
- Mysteel / SMM — Mysteel (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.