P420M is a thermomechanically rolled fine-grain steel designed for use in pressure vessels and boilers, manufactured according to the European standard EN 10028-5.
Nomenclature Breakdown
P: Indicates its suitability for Pressure purposes.
420: Refers to the minimum Yield Strength of 420 MPa for the lowest thickness range.
M: Signifies the Thermomechanical Rolling (TMCP) delivery condition
GNEE offers the P420M boiler plate specification:
Thickness: 6MM to 300MM or as per your requirement;
Width: 1500 mm to 4050 mm or as per your requirement;
Length: 3000 mm to 15000 mm or as per your requirement.
Mechnical property for P420M steel plate:
| Thickness(mm) | Yield strength (≥Mpa) | Tensile strength (Mpa) | Elongation in ≥,% |
| T≤16 | 420 | 500-660 | 19 |
| 16<T≤40 | 400 | ||
| 40<T | 390 |
Chemical composition for P420M steel plate (Heat Analysis Max%)
| Main chemical elements composition of P420M steel plate | ||||||
| C | Si | Mn | P | S | Al (total) | N |
| 0.16 | 0.50 | 1.70 | 0.025 | 0.020 | ≥0.020 | 0.020 |
| Mo | Nb | Ni | Ti | V | Cr+Cu+Mo | |
| 0.20 | 0.05 | 0.50 | 0.05 | 0.10 | 0.60 | |
Mechanical Properties
| Thickness (mm) | Yield Strength (MPa) | Tensile Strength (MPa) | Elongation (%) |
|---|---|---|---|
| ≤ 16 | min. 420 | 500 – 660 | min. 19 |
applications
1. Energy & Power Generation
Boiler Drums: Used as the main shell for high-pressure boilers in power plants to handle steam generation.
Hydropower: Fabrication of high-pressure water pipes (penstocks) for hydroelectric stations.
Nuclear & Thermal: Components for nuclear reactor pressure shells and steam generators.
2. Petrochemical & Chemical Industry
Storage Tanks: Aboveground and underground tanks for storing volatile fuels, liquefied gas (LPG), and liquid natural gas (LNG).
Processing Equipment: Manufacturing of reactors, heat exchangers, and spherical gas storage tanks.
Transport: Pressurized railroad tank cars designed for the safe transit of hazardous liquids and chemicals.
3. Industrial Infrastructure
Steel & Cement Plants: Used in industrial structures that require enhanced mechanical properties at high working temperatures.
Mechanical Engineering: High-load structural components where safety and resistance to brittle fracture are critical.
4. Low-Temperature Variants
While standard P420M is tested for impact at -20°C, its subgrades are used for more extreme environments:
P420ML1: For applications reaching -40°C.
P420ML2: For extreme cold service down to -50°C.
application condition
1. Temperature Range
High-Temperature Limit: P420M maintains high mechanical strength up to 500°C. However, it should not be used in environments exceeding 580°C–600°C, as excessive heat will degrade the fine-grain structure achieved during thermomechanical rolling.
Low-Temperature Toughness:
P420M: Tested for impact resistance at -20°C.
P420ML1/L2: Required for cryogenic or arctic conditions, supporting temperatures down to -50°C.
2. Operating Pressure
High-Stress Service: With a minimum yield strength of 420 MPa, it is designed for equipment operating under significant internal or external pressure, such as gas storage spheres and industrial boilers.
Safety Factor: It is specifically chosen when a high strength-to-weight ratio is needed to reduce wall thickness in large-scale pressure vessels.
3. Fabrication & Processing Constraints
Welding: Excellent weldability due to low Carbon Equivalent (CEV). However, for thicknesses exceeding 30–40mm, Post-Weld Heat Treatment (PWHT) is often mandatory to relieve residual stresses, typically performed between 530°C and 580°C.
Cold Forming: Suitable for cold bending and flanging. If cold deformation exceeds 5%, additional heat treatment may be required to restore ductility.
Hot Forming: Generally not recommended because heating above the transformation temperature destroys the properties gained from thermomechanical rolling. If hot forming is necessary, the material effectively becomes a normalized grade (like P420NH).
4. Environmental & Chemical Resistance
Sour Service: In oil and gas applications, if the steel is treated to have very low sulfur content, it can be used in environments containing H₂S (Hydrogen Sulfide) to resist Hydrogen Induced Cracking (HIC).
Corrosion: Like most carbon steels, it requires external coating or internal lining if exposed to highly corrosive chemicals or marine environments.
For more details about GNEE's steel products, contact us at beam@gneesteelgroup.com. We look forward to working with you.
What is P420M mainly used for in industrial applications?
P420M is a high-performance material widely used in industrial fields like mechanical manufacturing, engineering machinery and auto parts. It offers excellent strength and wear resistance, suitable for components under high load and harsh working conditions.
What are the key mechanical properties of P420M?
The key mechanical properties of P420M include high tensile strength, good yield strength and toughness. It also has outstanding fatigue resistance and impact resistance, ensuring stable performance in long-term and heavy-duty operations.
Is P420M corrosion-resistant?
P420M has moderate corrosion resistance to general atmospheric and mild chemical environments. For harsh corrosive conditions like strong acids or alkalis, additional anti-corrosion treatments such as coating or galvanizing are recommended to extend its service life.
What is the melting point range of P420M?
The melting point range of P420M is typically between 1450°C and 1500°C. This high melting point makes it suitable for high-temperature processing and applications where it may be exposed to elevated temperatures for short periods.
Can P420M be welded easily?
P420M can be welded with proper techniques and materials. It is recommended to use matching welding electrodes and preheat the material before welding to reduce internal stress and avoid cracks in the weld joint.
What processing methods are suitable for P420M?
P420M is compatible with various processing methods, including forging, rolling, machining (turning, milling, drilling) and heat treatment. Its good machinability allows for precise shaping into complex components for industrial use.
What is the density of P420M?
The density of P420M is approximately 7.85 g/cm³, which is similar to common carbon and low-alloy steels. This density ensures good structural stability and load-bearing capacity in applications.
What heat treatment processes is P420M suitable for?
P420M is suitable for heat treatment processes like quenching and tempering. Quenching enhances its hardness and strength, while tempering improves toughness and reduces brittleness, optimizing its overall mechanical performance.
Is P420M suitable for making automotive components?
Yes, P420M is very suitable for making automotive components. Its excellent strength, wear resistance and impact resistance meet the requirements of key parts like gears, axles and chassis components, ensuring safe and reliable operation.
What is the difference between P420M and P420 steel?
The main difference between P420M and P420 steel lies in impurity content and mechanical uniformity. P420M has lower harmful impurities, better toughness and more stable performance, making it suitable for higher-demand industrial applications.