What is the yield strength of P355NH?

What is the yield strength of P355NH?

The yield strength of P355NH steel is typically a minimum of 355 MPa (N/mm²), but it varies by thickness, with thinner sections sometimes having higher yield strengths (e.g., ≥355 MPa for thicker plates) and thicker sections showing lower minimums (e.g., ≥295 MPa for very thick plates >150mm) as per EN 10028-3 standards, being a normalized fine-grain steel for pressure vessels.

P355NH is a high-strength steel grade designed for compliance with the Pressure Equipment Directive (PED) 2014/68/EU. It is a safety-critical material used when the failure of a vessel could result in catastrophic energy release. Its production involves strict quality control at the mill to ensure it meets the demanding safety factors of modern engineering.

Decoding the Name:

P: Mandatory for any component under the "Pressure" category in European jurisdictions.

355: Yield strength of $355$ MPa, providing robust mechanical performance.

N: Grain refinement through heat treatment to prevent crack propagation.

H: Certified "High Temperature" properties.

Key Comparison:

A critical distinction is between P355NH and S355NH. Although both have a $355$ MPa yield and are normalized, the "S" grade is for Structural use (buildings/bridges) and does not undergo the high-temperature yield testing or the strict internal quality checks required for the "P" (Pressure) designation.

Key Characteristics:

Traceability: Each plate is stamped with a unique heat number, allowing for full "cradle-to-grave" tracking in safety audits.

Ductility: High elongation (approx. $20-22\%$) ensures the metal can "stretch" and redistribute stress rather than failing abruptly.

Aging Resistance: The chemical balance is designed to prevent the steel from becoming brittle over decades of service.

Common Applications:

Nuclear and thermal power plant components, high-pressure gas headers, and offshore oil/gas processing modules.

What are the properties of P355NH?

P355NH is a weldable, fine-grained pressure vessel steel (EN 1.0565) known for good strength, weldability, and resistance to brittle cracking at elevated temperatures (up to around 400°C) and low temperatures, supplied in a normalized condition for building gas tanks, boilers, and pressure piping. Key properties include a minimum yield strength of 275-355 MPa (depending on thickness), excellent toughness, and a fine microstructure, making it ideal for demanding applications.

What is P355NH equivalent to ASTM material?

P355NH (EN 1.0565) is a European standard fine-grained pressure vessel steel, most commonly equivalent to ASTM A516 Grade 70 (ASME SA-516 Gr. 70), used for elevated temperature service, but also shows equivalency to ASTM A662 Grade C for tubes/pipes, and sometimes related to ASTM A537 Class 1, depending on the specific application and required properties.

What is P355NH material standard?

is steel for pressure purposes (P) with minimum yield strength of 355 MPa (355) which has specified elevated temperature properties (NH).

Equivalent grades of steel P355NH (1.0565)

Warning! Only for reference

Chemical composition % of steel P355NH (1.0565): EN 10028-3-2009

Mechanical properties of steel P355NH (1.0565)

1What is the machinability of P355NH?

P355NH steel offers good machinability, often compared to mild steels, thanks to its fine-grained structure and normalization, allowing for efficient machining in pressure vessel applications, but its performance depends on tooling and cutting speeds, generally suitable for general machining with attention to tool wear. It's a weldable, non-alloy pressure vessel grade with high strength, used for high-pressure and high-temperature service where its machinability supports creating durable components like boilers and pipes.

2What is P355NH steel comparable to?

P355NH steel (EN 1.0565) is a normalized, weldable fine-grain steel for pressure vessels, comparable to other P355 grades like P355GH (for high temps) and P355NL1/NL2 (for low temps), with similar strength levels but tailored for different temperature ranges, sharing properties with grades like WStE 355 (German) and A 510AP (US/International).

3What number is P355NH steel?

Material Description Material Number Material Name Material Number (single) 1.0565 (DIN EN 10028-3 : 2017-10) P355NH 1.0565

4What temperature will damage P355NH?

P355NH steel is designed for elevated temperatures, commonly used up to around 400°C (750°F) for pressure vessels, but significant strength loss starts to occur above 300°C (572°F), with rapid weakening and potential deformation above 400°C (750°F), though its ultimate failure depends on load, duration, and specific service conditions. Damage isn't a sudden event but a gradual loss of strength and stiffness.

5What is the price of P355NH?

The price of P355NH steel varies significantly by supplier, quantity, thickness, and form (plate, pipe), generally ranging from around $400 to over $900 per ton, with specific examples showing plates at $0.35-$1.50/kg or valves at $225 each; large orders can lower unit prices, while smaller amounts or specific dimensions increase costs.

6What is P355NH material?

A pressure vessel steel grade with good weldability and high resistance to brittle cracking, P355NH is used by the world's fabricators for the manufacture of pressure vessel tanks for the storage of pressurised gases.

7What is the technical Condition of P355NH?

P355NH is a fine-grained, normalized structural steel for pressure vessels, known for good weldability and excellent resistance to brittle fracture, especially at low temperatures, with a minimum yield strength of 355 MPa, suitable for high-pressure gas tanks and boilers up to about 400°C. Its technical condition involves a controlled chemical composition (low Carbon, plus Al, Nb, V for grain refinement), fine-grained microstructure from normalizing, and guaranteed low-temperature impact toughness, making it ideal for demanding applications.

Contact now

If you want to learn more about P355NH GNEE's products, you can send an email toinfo@gneesteels.com . We are more than happy to assist you.