P245NB steel (1.0111) is a specialized, non-alloy European quality steel (EN 10120) designed for manufacturing low-pressure welded gas cylinders and LPG vessels. It offers an ideal combination of 255 MPa minimum yield strength, high ductility, and excellent weldability, ensuring safety and performance in pressure cycling and forming operations.
The choice of material for these cylinders is of paramount importance as it directly impacts their performance, safety, and longevity. P245NB steel has emerged as an ideal candidate for manufacturing low-pressure welded gas cylinders due to its unique combination of properties.
As a premier global steel manufacturer and supplier, GNEE specializes in providing high-quality gas cylinder steel plates that meet stringent international standards. Whether you are producing LPG tanks or industrial gas containers, understanding the nuances of P245NB steel is essential for your engineering decisions.
P245NB steel
Key Characteristics and Technical Properties of P245NB steel
Standard & Grade: EN 10120 P245NB (Material Number 1.0111)
Mechanical Properties:
- Yield Strength: > 255 MPa.
- Tensile Strength: 360-450 MPa
- Elongation: Good ductility for deep-drawing operations, ensuring structural integrity during, for example, the manufacture of LPG cylinders.
Chemical Composition (Max %): Low carbon equivalent for excellent weldingperformance (e.g., C ≤ 0.20%, Si≤ 0.25%, P ≤ 0.025%, S ≤ 0.015%).
Delivery Condition: Typically Normalized (N), As Hot Rolled (AR), or Normalized andTempered, providing a fine grain structure.
Properties Of P245NB Steel That Make It Ideal For Low-Pressure Welded Gas Cylinders
Excellent Weldability
Mechanism: P245NB steel has a relatively low carbon content (up to 0.16%), which reduces the risk of hardening and cracking during the welding process. Low carbon content means less carbon is available to form brittle carbides at the grain boundaries, which are often the starting points for cracks in welded joints.
Advantage: This excellent weldability allows for the fabrication of complex-shaped gas cylinders through various welding techniques such as arc welding, gas welding, and laser welding. It ensures strong and reliable welds, which are essential for the structural integrity of the gas cylinders, especially under pressure.
Good Mechanical Properties
Strength: P245NB steel offers a good balance of strength and ductility. It has a minimum yield strength of 245 MPa, which provides sufficient strength to withstand the internal pressure exerted by the stored gas without undergoing excessive deformation.
Ductility: The steel's ductility allows it to deform plastically under stress without suddenly fracturing. This is crucial in the event of overpressure or accidental impacts, as it gives the cylinder some ability to absorb energy and prevent catastrophic failure.
production process of P245NB steel
Toughness at Low Temperatures
Microstructure Influence: The microstructure of P245NB steel, typically consisting of ferrite and pearlite, contributes to its toughness. The presence of manganese (up to 0.3%) in the steel helps to refine the grain structure and improve the toughness, especially at lower temperatures.
Application Significance: In many practical scenarios, gas cylinders may be exposed to low temperatures during transportation or storage. The toughness of P245NB steel ensures that the cylinder remains intact and does not develop cracks due to brittle fracture under such conditions.
Corrosion Resistance
Surface Treatment Compatibility: P245NB steel can be easily coated or treated to enhance its corrosion resistance. For example, it can be painted, galvanized, or subjected to other surface treatments to protect it from the corrosive effects of the stored gas and the external environment.
Longevity: Good corrosion resistance extends the service life of the gas cylinders, reducing the need for frequent replacements and maintenance, which is cost-effective in the long run.
How to Select P245NB Steel for Low-Pressure Welded Gas Cylinders
Meet standard specification：Select material complying with EN 10120 (1.0111), ensuring chemical and mechanical properties match P245NB requirements.
Suitable pressure class：Choose P245NB for low‑pressure gas cylinders; its yield strength ≥245 MPa provides sufficient pressure resistance without over‑engineering.
Excellent weldability：Prefer low carbon equivalent (C ≤ 0.16%, low P/S) to avoid welding cracks and ensure stable seam performance.
Good formability：High elongation and uniform structure enable deep drawing and forming of cylinder bodies, tops, and bottoms without fracture.
Stable thickness & quality：Select steel with consistent gauge and uniform mechanical properties to ensure reliable pressure containment.
Compliance with safety approval：Ensure the material is certified for gas cylinder production and meets national or regional pressure vessel safety regulations.
P245NB Steel for Low-Pressure Welded Gas Cylinders
Conclusion
P245NB steel's excellent weldability, good mechanical properties, toughness at low temperatures, and corrosion resistance make it an ideal material for low-pressure welded gas cylinders. By carefully considering factors such as the gas type, operating pressure and temperature, quality certification, and fabrication requirements, one can select the most appropriate P245NB steel for a specific application. This ensures the safe and reliable storage and transportation of gases, contributing to the overall efficiency and sustainability of various industries.
Why Choose GNEE as Your Supplier?
18+ years manufacturing experience
Full certification support (EN, JIS, GB standards)
Custom sizes, thickness, and surface treatment
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Strict quality inspection (chemical + mechanical testing)
We don't just sell steel-we provide complete gas cylinder material solutions.
What Chinese grade corresponds to P245NB?
There is no Chinese grade that directly corresponds to P245NB. HP295 (GB 6653 Steel Plate for Welded Gas Cylinders) is similar in application, but its chemical composition and performance requirements differ, so it cannot be directly substituted.
What is the thickness tolerance?
The thickness tolerance of P245NB conforms to EN 10051:2010. For specific requirements, tighter tolerances (such as 75%, 66%, 60%, 50%, 33% of the standard tolerance) are available.
What are the properties of the weld heat-affected zone (HAZ)?
The low-carbon design and microalloying scheme of P245NB ensure that the weld heat-affected zone (HAZ) exhibits good toughness and strength. Studies have found that this steel exhibits ductile fracture characteristics at 1100°C and 1050°C, semi-ductile fracture at 1000°C, and brittle fracture at 800°C.
How is the weldability of P245NB evaluated?
Excellent. P245NB can be welded using conventional welding methods.
How does this steel perform at low temperatures?
P245NB steel has good toughness at low temperatures and is not easily brittle, making it suitable for use in cold environments and ensuring the safety of gas cylinders.
