What is the P355Q material equivalent to?
P355Q (EN 1.8866) is a quenched and tempered, weldable fine-grain steel for pressure purposes, often compared to ASTM A537 Class 3 or having properties similar to S355 grade steels, though direct ASTM/SAE equivalents aren't identical, but ASTM A537 Class 3 offers comparable strength for pressure vessels. Other closely related European grades include P355QH, P355QL1, and P355QL2, with variations in tempering or cooling.
P355Q (1.8866) is a High-Performance Pressure Vessel Plate used as a baseline for stress calculations. In engineering design codes like ASME Section VIII or EN 13445, P355Q provides a reliable yield point that allows for the optimization of wall thickness in vessels that must withstand significant cyclic loading.
Key Characteristics
Yield-to-Tensile Ratio: P355Q has a very predictable yield-to-tensile ratio, allowing engineers to push safety factors to their most efficient limits.
High Allowable Stress: Because it is a "Q" grade, it often maintains higher allowable stress values at moderate temperatures compared to standard carbon steels.
Thickness Availability: Frequently supplied as heavy plate (up to 150 mm or more), maintaining its properties even in thick sections.
Elastic Modulus: Standard for steel , providing the stiffness required for large industrial shells.
Comparison
Vs. P265GH: P265GH is the "workhorse" of the industry but has much lower strength. Using P355Q instead of P265GH allows an engineer to reduce vessel weight by nearly 30%.
Vs. S460Q: While S460Q is stronger 460 MPa, P355Q is often preferred for pressure vessels because it offers higher ductility and a larger "buffer" before failure, which is preferred by safety inspectors.
Common Application
Offshore Separators: Pressure vessels on oil platforms where weight reduction is vital.
Hydroelectric Penstocks: Large diameter pipes that carry high-pressure water to turbines.
Steam Accumulators: Large vessels designed to store steam energy in power plants.
What factors influence prices for P355Q ?
Prices for P355Q, a high-strength quenched and tempered (Q+T) steel plate for pressure vessels, are influenced by core steel market factors like raw material costs (iron ore, scrap, alloys), energy prices, global supply and demand (especially in construction/energy), production costs (energy, labor), trade policies, and specific technical specs (thickness, width, certifications), with market dynamics, competitor pricing, and economic health also playing significant roles.
What are the typical application fields of P355Q ?
P355Q steel, a quenched and tempered fine-grain steel under EN 10028-6 standard, is primarily used for fabricating pressure vessels, boilers, and high-temperature equipment due to its excellent weldability and strength at elevated temperatures, finding applications in the oil, gas, and petrochemical industries for components like reactors, storage tanks, and heat exchangers.
What is the difference between P355Q and P355QL1?
P355Q and P355QL1 are both quenched and tempered pressure vessel steels with similar compositions, but the primary difference lies in their impact toughness requirements at low temperatures, with the 'L1' designation indicating enhanced low-temperature toughness for P355QL1, making it better suited for colder service conditions than P355Q. Think of 'Q' as Quenched & Tempered, 'L' as Low-Temperature toughness, and the number '1' (or '2' for P355QL2) as increasing levels of impact energy absorbed.
Chemical composition % of steel P355Q (1.8866): EN 10028-6-2009
| C | Si | Mn | Ni | P | S | Cr | Mo | V | N | Nb | Ti | Cu | Zr | B |
| max 0.16 | max 0.4 | max 1.5 | max 0.5 | max 0.025 | max 0.01 | max 0.3 | max 0.25 | max 0.06 | max 0.015 | max 0.05 | max 0.03 | max 0.3 | max 0.05 | max 0.005 |
Mechanical properties of steel P355Q (1.8866)
| Nominal thickness (mm): | to 100 | 100 - 150 |
| Rm - Tensile strength (MPa) (+QT) | 490-630 | 450-590 |
| Nominal thickness (mm): | to 50 | 50 - 100 | 100 - 150 |
| ReH - Minimum yield strength (MPa) (+QT) | 355 | 335 | 315 |
| KV -Impact energy (J) transverse, (+QT) | -20° 27 |
0° 40 |
+20° 60 |
| A - Min. elongation at fracture (%) (+QT) | 22 |
1What is P355Q Plate Thickness?
P355Q is a grade of weldable, fine-grain steel plate (EN 10028-6) used for pressure vessels, and its plate thickness typically ranges from 6 mm up to 300 or 400 mm, though it can vary by supplier, with specific thickness limits depending on the exact grade variant (Q, QH, QL1, QL2) and application requirements, often provided quenched and tempered (+QT).
2What does Q mean in P355Q material ?
In P355Q steel (EN 10028-6 standard), the "Q" indicates the steel is Quenched and Tempered, a heat treatment process that improves strength, hardness, and toughness, making it suitable for pressure vessels and high-temperature equipment, with the "355" denoting the minimum yield strength of 355 MPa for certain thicknesses, while suffixes like "L2" (e.g., P355QL2) specify lower temperature impact toughness.
3What is the difference between P355Q and P500Q?
P355Q and P500Q refer to weldable fine grain steels under European standards (EN 10028-6) for pressure purposes, with the main difference being their strength levels: P355 typically has a minimum yield strength of 355 MPa (megapascals), while P500 signifies a higher minimum yield strength, around 500 MPa, offering greater load-bearing capacity, making P500Q suitable for more demanding high-pressure applications than P355Q.
4What is the chemical composition of P355Q material ?
P355Q is a normalized/quenched & tempered (Q) pressure vessel steel, primarily iron, with key alloying elements like Carbon (≤0.16%), Manganese (≤1.5%), Silicon (≤0.4%), Phosphorus (≤0.025%), Sulfur (≤0.010%), Chromium (≤0.3%), Nickel (≤0.5%), Molybdenum (≤0.25%), Vanadium (≤0.06%), Niobium (≤0.05%), and Titanium (≤0.03%), offering good strength, toughness, and weldability for high-pressure applications in the chemical and energy industries.
5What is the price of P355Q?
The price of P355Q, a type of pressure vessel steel plate, varies significantly by quantity and supplier, ranging roughly from $0.70 to over $1.00 per kilogram for large orders, but can be much higher for smaller quantities or specific parts like an "R/P 355 Q" component (around $375 for a single item).
6What is the difference between P355 and S355?
P355 and S355 are both European steel grades with a minimum yield strength of 355 MPa, but they serve different purposes: P355 (e.g., P355GH) is designed for pressure vessels and high-temperature service, while S355 is a general structural steel for construction, with variations like S355JR for general use and S355NL for low-temperature toughness. The key difference lies in their specific EN standards (EN 10028 for P355 vs. EN 10025 for S355) and application focus, with P355 having specific requirements for elevated temperatures and S355 for structural strength and weldability.
7Can P355Q steel be welded?
Yes, P355Q steel is specifically designed to be weldable, as it's a European standard weldable fine-grained steel (EN 10028-6) used for pressure vessels and boilers, offering good plasticity and welding performance, though proper techniques like preheating (for cold temperatures) and appropriate filler metals are crucial for maintaining joint integrity.
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