A204 Alloy Steel Plate for Pressure Vessel
GNEE ASTM A204 alloy steel plates are premium molybdenum-alloy pressure vessel materials engineered for exceptional high-temperature strength, creep resistance, and weldability. Fully compliant with ASTM A204/A204M and ASME SA204/SA204M standardsASTM International, these plates are ideal for welded boilers, pressure vessels, and high-pressure components in critical industries like power generation, petrochemicals, and refining.
Available in Grade A, Grade B, and Grade C, GNEE A204 plates offer tailored strength levels to match your project's design conditions, with controlled molybdenum content ensuring long-term reliability in elevated temperature and pressure environmentsASTM International
What is ASTM A204 Alloy Steel Plate?
ASTM A204 is a standard specification for molybdenum alloy steel plates intended for pressure vessels and boilers operating at moderate and elevated temperatures. The addition of molybdenum enhances high-temperature strength and creep resistance.
Available Grades:
A204 Grade A
A204 Grade B
A204 Grade C
Each grade provides different strength levels to meet various engineering requirements.
A204 vessel plate chemical composition
| Elements Composition % | ||||
|---|---|---|---|---|
| Grade A | Grade B | Grade C | ||
| Carbon, max: | ||||
| up to 1 in. [25 mm] incl. in thickness | 0.18 | 0.20 | 0.23 | |
| Over 1 in. to 2 in [50 mm] incl. in thickness | 0.21 | 0.23 | 0.26 | |
| Over 2 in. to 4 in. [100 mm] incl. in thickness | 0.23 | 0.25 | 0.28 | |
| Over 4 in. [100 mm] incl. in thickness | 0.25 | 0.27 | 0.28 | |
| Manganese, max: | ||||
| Heat analysis: | 0.90 | 0.90 | 0.90 | |
| Product analysis: | 0.98 | 0.98 | 0.98 | |
| Phosphorus, max | 0.025 | 0.025 | 0.025 | |
| Sulfur, max | 0.025 | 0.025 | 0.025 | |
| Silicon: | ||||
| Heat analysis | 0.15-0.40 | 0.15-0.40 | 0.15-0.40 | |
| Product analysis | 0.13-0.45 | 0.13-0.45 | 0.13-0.45 | |
| Molybdenum: | ||||
| Heat analysis | 0.45-0.60 | 0.45-0.60 | 0.45-0.60 | |
| Product analysis | 0.41-0.64 | 0.41-0.64 | 0.41-0.64 | |
a204 boiler plate mechanical property
| Mechanical Property of ASTM A204 steel plate | Grade A | Grade B | Grade C |
|---|---|---|---|
| Tensile strength, kis [MPa] | 65-85 [450-585] | 70-90 [485-620] | 75-95 [515-655] |
| Yield strength, min, kis [MPa] | 37 [255] | 40 [275] | 43 [295] |
| Elongation in 8 in. [200 mm], min, % | 19 | 17 | 16 |
| Elongation in 2 in. [50 mm], min, % | 23 | 21 | 20 |
a204 pressure vessel steel Equivalent steel grade
| ASTM | GB | JIS | DIN | EN | |||||
|---|---|---|---|---|---|---|---|---|---|
| Steel Grade | Steel Grade | Steel Grade | Standard Number | Steel Grade | Material Number | Standard Number | Steel Grade | Material Number | Standard Number |
| A204-Gr. A.B | 16Mo | 16Mo | G3103 | 15 Mo3 | 1.5414 | DIN17155 | 16Mo3 | 1.5415 | EN 10028-2 |
GNEE can supply ASTM A204 Steel Plates from stock or from reputable steel mills. We also provide steel fabrication services, where steel plates can be cut (to any size and any shape), drilled, welded, milled, machined, etc. to suit your needs. Our steel mill has fabrication staff with 5-10 years of experience. If you are interested in purchasing ASTM A204 Steel Plate products, please contact us today for the latest prices or check the table below for equivalent steel grades to ASTM A204.
Key Features of A204 Alloy Steel Plate
1. Excellent High-Temperature Strength
Maintains mechanical performance under elevated temperatures.
2. Creep Resistance
Suitable for long-term service in high-temperature environments.
3. Good Weldability
Easy to fabricate using conventional welding processes.
4. Molybdenum Alloy Advantage
Improves heat resistance and structural stability.
5. Reliable Performance
Designed for critical pressure vessel and boiler applications.
ASTM A204 vs Other Pressure Vessel Steels
| Grade | Key Feature | Application |
|---|---|---|
| ASTM A204 | Mo alloy, high temp resistance | Boilers, high-temp vessels |
| ASTM A516 | Carbon steel, general purpose | Standard pressure vessels |
| ASTM A387 | Cr-Mo alloy, higher temp resistance | High-temp & high-pressure service |
ASTM A204 is ideal for moderate to high temperature environments, while A387 is preferred for more demanding high-temperature applications.
Typical Applications Of A204 Pressure Vessel Steels
Power Generation: Steam drums, superheater headers, high-pressure piping, and turbine components.
Petrochemical & Refining: Pressure reactors, heat exchangers, separators, and storage tanks.
Boilers & Pressure Vessels: Welded boilers, atmospheric/vacuum distillation units, and heat recovery steam generators.
Chemical Industry: Vessels handling high-temperature fluids and gases in corrosive environments.
Custom A204 Alloy Steel Plate Solutions
At GNEE Steel, we provide fully customized ASTM A204 plates tailored to your project needs:
Customization Options:
- Cut-to-size plates based on drawings
- Grade selection (Gr.A / Gr.B / Gr.C)
- Heat treatment control (Normalized, special requirements)
- Impact testing & inspection
- Surface processing (cutting, beveling, drilling)
- Third-party certification (SGS, BV, TUV)
FAQ – A204 Alloy Steel Plate for Pressure Vessel
What is the equivalent of ASTM A204 Grade A?
Additionally, ASTM A204 Gr. A and B are sometimes considered equivalents of EN 16Mo3 and 15Mo3 respectively.
What is ASTM A204?
ASTM A204 specification covers molybdenum alloy steel plates, intended particularly for welded boilers and other pressure vessels. Plates under this specification are available in three grades having different strength levels: Grade A; Grade B; and Grade C.
What is SA 204 material?
molybdenum alloy
ASME SA204 Gr. B Pressure vessel steel plate is a kind of Mo-alloy steel material used to fabric high temperature pressure vessels. SA204 steel grade specification covers molybdenum alloy, intended particularly of welded boilers and others pressure vessels steel plate in SA204 Gr.
What is SA 204 GR B material?
The SA 204 GR B specification covers the molybdenum alloy plates, and they are particularly intended for welded boilers and various other types of pressure vessels. The Astm A204 Grade B Plate is used in high temperature situations, and they come with higher yield and tensile strength.
What is A204 Grade B equivalent to?
ASTM A204, a pressure vessel plate standard, has several equivalent grades in other standards. ASTM A204 equivalent steel grades include: EN 16Mo3, 15Mo3, DIN 17155, and JIS G3103. ASTM A204, specifically Gr. B, is also equivalent to ASTM A387.
What is the chemical composition of SA 204?
Chemical Composition of SA 204 Grades
Carbon equivalent (CEQ) is controlled for weldability: CEQ = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15 ≤ 0.45% for all grades. Molybdenum: Enhances high-temperature strength and creep resistance. Carbon: Limited to ≤0.20% to balance strength and weldability.
What is the composition of ASTM A204 Grade B?
The Astm A204 Grade B Plate is designed with a superior composition of carbon, molybdenum, manganese sulfur, phosphorus, and silicon. The content embedded in these plates gives them enhanced resistance to corrosive and reducing media.
What is the chemical composition of SA 204 GR C?
Chemical Composition of SA 204 Grades
Carbon equivalent (CEQ) is controlled for weldability: CEQ = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15 ≤ 0.45% for all grades. Molybdenum: Enhances high-temperature strength and creep resistance. Carbon: Limited to ≤0.20% to balance strength and weldability.
What is ASTM A204 steel used for?
It is used for pressure vessels and boilers operating at elevated temperatures.
What is the main alloying element in A204?
Molybdenum (Mo), which improves high-temperature strength.
What grades are available?
A204 Grade A, B, and C.
Is ASTM A204 suitable for high temperatures?
Yes, it is designed for moderate to high temperature service.
What is the difference between A204 and A516?
A204 is alloy steel for high temperature, while A516 is carbon steel for general use.
Can A204 steel be welded?
Yes, it has good weldability with proper procedures.
What industries use A204 steel?
Power plants, petrochemical, oil & gas, and boiler manufacturing.
What is the equivalent EN grade?
16Mo3 is the most common equivalent.
What thickness can GNEE supply?
Typically from 6mm to 150mm.
Can GNEE provide customized plates?
Yes, full customization and processing services are available.
Why Choose GNEE A204 Plates?
At GNEE, we deliver 100% mill-tested A204 alloy steel plates with unmatched quality and global support:
- Expert Technical Support: Our engineers help select the optimal grade for your design temperature, pressure, and application needs.
- Rigorous Quality Control: Full ultrasonic testing (UT) per A578 Level B and comprehensive documentation to meet international project standards.
- Precision Processing: Custom cutting, shearing, and drilling to reduce on-site fabrication time and costs.
- Global Logistics: Secure packaging and efficient worldwide delivery to meet your project deadlines.
Ready to source high-quality ASTM A204 pressure vessel steel plates?Connect with GNEE today for a free quote and detailed technical datasheet. Our team is ready to support your next critical project.
Email: alloy@gneesteelgroup.com
FAX: +86-372-5055135
WeChat/WhatsApp: +86 15824687445
GNEE – Your Reliable Global Supplier of High-Performance Pressure Vessel Steel Plates
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Relying on many first-class equipment, such as CNC Shearing machine, Press Brake machine, Straightening machine, Roll Bending machine, Flat Bar Machine, Deburring machine etc, GNEE STEEL could provide various semi-productsand extensive forming services to customers.
GNEE STEEL PROCESSING
1.CTL & SL SERVICE (141 SETS)
Currently, GNEE STEEL has imported manyadvanced CTL/SL equipment from Italy and Korea and could provide customized CTL/SL services from cold rolled stainless steel and carbon steel to hot rolled stainless steel and carbon steel as well as strips and ultra-wide sheet.
CTL FACILITIES
Max Length:16500mm
Max Width:2200mm
Max Thickness:25.4mm
Max Yield Strength:1500Mpa
SL FACILITIES
Max Width:2200mm
Max Thickness:18mm
Max slit Quantity:31
Max Yield Strength:1200Mpa
2.CUTTING SERVICE
GNEE STEEL imported lots of advanced cutting machines from Germany, Sweden, America and Japan, including plasmas cutting machine, water jet cutting machine, laser cutting machine, flame cutting machine and saw machine. In order to meet customers' diversified needs, GNEE STEEL also adopts nest working multi-cutting methods and intensive production to improve production capacity and save costs for the customers.
Laser Cutting Machine
Max Cutting Length:40,000mm
Max Width:4,600mm
Max Thickness:100mm
Flame Cutting Machine
Max Cutting Length:40,000mm
Max Width:8,000mm
Max Thickness:500mm
Plasmas Cutting Machine
Max Cutting Length:30,000mm
Max Width:5,000mm
Max Thickness:100mm
Water-jet Cutting
Max Cutting Length:12,000mm
Max Width:4,010mm
Max Thickness:250mm
3.FORMING SERVICE
Steel Plate Roll Bending
Maximum Rolling Thickness: up to 200mm
Maximum Width: 4200mm
Automatic Bending Machine-Press Brake
Max Bending Capability:3000Ton
Max Bending Length:15,000mm
Expert in Bending High-Strength & Wear-Resistant Steels
Punching Machine
Max Width:3,070mm
Max Thickness:8mm
Max Pressure:250t
BEVELING SERVICE
GNEE STEEL beveling platform has edge milling machine, edge planer, flame / plasma groove cutting machine, flame groove cutting robot, desktop chamfering machine, gantry planerand other advanced equipment to provide customers with parts prefabrication services,daily processing of V-type, Y-type, X-type and U-type grooves, and guarantee subsequent processes such as welding and assembly of products.
Milling：
Max Cutting Length:18,000mm
Max Width:4500mm
Max Thickness:120mm
Beveling:
Max Length:16,000mm
Max Thickness:80mm
MACHINING SERVICE
GNEE STEEL owns CNC Portal-type Boring and Milling machine,CNC Floor-type Boring and Milling machine, Vertical Precision 5-axis Milling Machine, Portal-type Planer, Vertical Lathe, Cylindical Grinding machine, Hydraulic Planer and CNC Lathe and could provide fine machining of large spare parts and structural parts for customers.
Gantry Type Boring & Milling Maching Center
Max Length:48000mm
Max Width:12500mm
Max Height:8000mm
Max Diameter:10500mm
Deep-hole Drilling Equipment
Max Driling Depth:1,100mm
Max Bore Diameter:φ80mm
Max Diametar:φ4,500mm
MMulti-hole Drilling Equipment
Max Length:13,000mm
Max Width:10,000mm
Max Bore Diameter:φ105mm
Max Drilling Depth:250mm
Floor Boring And Milling Machine
Max Length:24,000mm
Max Height:8,000mm
Turntable Dimensions:9x5m
Vertical Lathe
Max Height:6,000mm
Max Diametar:φ22,00mm
Automated Edge Milling Machine
The Automated Edge Milling Machine is a leading product in heavy-duty milling equipment. It is primarily used for weld groove preparation (beveling) on large-format plates made of stainless steel, carbon steel, and special steel grades. It can process plates with a maximum thickness of up to 90mm, a length of 16 meters, and a width of 4 meters.
It is equipped with dual milling units and a fully automatic milling cutter head changing system, enabling automated 4-edge beveling. Its standout feature is the profiling technology used when milling wavy plates and irregularly shaped products, which ensures absolute consistency of the groove after milling.
Utilizing specially designed milling cutter heads, it can execute highly difficult and complex groove profiles in a single pass.
Materials: Plain carbon steel, pressure vessel steel, wear-resistant steel, high-strength steel, stainless steel, nickel-based alloys, etc.
Width: 1200 - 4200 mm
Length: 5800 - 16000 mm
Thickness: 5 - 90 mm
Weight: Up to 35 tons
This edge milling machine is the world's premier automated bevel milling equipment. With its excellent structural design and advanced data algorithms, it achieves full automation from plate detection to the actual milling process, significantly improving processing efficiency while guaranteeing high precision.
- Processing Accuracy
Length accuracy: ±1mm when L < 10m; ±2mm when L > 10m;
Width accuracy: ±1mm;
Diagonal accuracy: ±2mm;
Root face accuracy (blunt edge): ±1mm for Y-grooves; +0.5mm for X-grooves.
- Processing Efficiency
The processing efficiency is more than 10 times that of conventional edge milling or edge planing equipment.
HEAT TREATMENT
Heat Treatment Furnace
Max Furnace Size:36x12x13.5m
Max Rated Temperature:1100℃
Max Loading Capacity:800t
Heat Treatment of Pressure Vessels
Heat Treatment of Mining Equipment
Heat Treatment of Tube Sheet
Heat Treatment of Pressure Vessel Head
Case : Steel Plates Supply for 100,000m³ Full Containment Ammonia Storage Tank Project
GNEE STEEL is currently participating in the procurement phase of a 100,000m³ full containment ammonia storage tank project, supplying high-quality steel plates for critical tank components. Due to the corrosive nature of ammonia and the risk of Ammonia Stress Corrosion Cracking (SCC), the project requires strict metallurgical control of materials according to EN 10028-3 standards.
One of the most important technical requirements of this project is the strict limitation of the actual Yield Strength (Re) for all NL2 grade materials. To prevent SCC risks in ammonia storage environments, the actual yield strength must not exceed 390 MPa, regardless of the nominal values specified in the standard or plate thickness ranges. This requirement places higher demands on steelmaking process control, heat treatment stability, and material testing.
Raw high-strength steel plates ready for the 100,000 m³ full containment ammonia storage tank production
Project Materials and Technical Requirements
The project mainly uses P355NL2 and P275NL2 normalized pressure vessel steel plates, which are widely applied in low-temperature storage tanks due to their excellent toughness and weldability.
Key technical specifications include:
- Material grades: P355NL2 and P275NL2 (Normalized)
- Yield strength: Standard minimum / Maximum limited to 390 MPa
- Hardness: ≤ 225 HBW in base material
- Impact testing: Charpy-V notch test at -50°C, minimum 27J
- Certification: EN 10204 3.1 certificate, with optional 3.2 certification
These strict requirements ensure that the steel plates maintain stable mechanical properties and high resistance to ammonia-induced stress corrosion during long-term operation.
Precision rolling and forming of steel plates into curved sections for the 100,000 m³ ammonia storage tank.
Project Plate Quantities and Thickness Distribution
The total steel demand for this ammonia storage tank project is several thousand tons, mainly distributed across different tank sections:
P355NL2 – Inner & Outer Tank Shell Plates
- Lower shell courses: 50 mm thickness – approx. 2,000 tons
- Middle shell courses: 25 mm thickness – approx. 1,400 tons
- Upper shell courses: 10 mm thickness – approx. 500 tons
P275NL2 – Tank Bottom Plates
- Thickness: 10–15 mm – approx. 750 tons
P275NL2 – Suspended Roof Structure
- Thickness: 5–8 mm – approx. 180 tons
S275JR – Outer Roof (Ambient Structure)
- Thickness: 10 mm – approx. 450 tons
To improve tank fabrication efficiency and reduce circumferential welds, the project also requires wide steel plates to minimize welding joints, which helps reduce the potential risk of SCC in ammonia service conditions.
Formed steel segments wrapped and racked for protection, ready for 100,000 m³ ammonia storage tank assembly.
GNEE STEEL provides high-precision steel plate rolling and cylinder fabrication solutions for tank manufacturers worldwide. Send us your plate specifications or fabrication drawings for a fast quotation.
| TYPE | GRADE | SPECIFICATIONS |
| Carbon Steel / Low Alloy Coil | Q235A/B/C/D/Q355B(Q345B)/C/D/E/SS400/SAPH400-C/ASTMA283Grade C |
0.7~2.0*1250/1500mm*C 2.3~19.5*1250/1500/1800/2000mm*C |
| Medium Heavy Plate | Q235B/Q355B(Q345B)/C/D/E | 6.0-200x150mm-4000mmxL |
| Vessel Plate |
Q245R/Q345R/HP295/SA516MGR485/SA516GR70/P355NL2/P275NL2/ S275JR//SPV490/ASTM A537 Class 1/Class 2 |
2.5-120x1500mm-3000mmxL |
| High Strength Steel |
510L/610L/700L/750L/BS600MCK4/BS700MCK2/BS700MCK4/ BS960E/BWELDY700QL2/L4/BWELDY960QL4/HG60D/70D/785D/ Q460D/Q550D/690D/690E/TQ600MCD/TQ700MCD/S700MCD/ WYS600/700/STRENX700MCE/Q490E/Q490D |
1.2-60x 1500mm-2500mmxL |
| Patterned Steel | HQ235A|B | 1.2-60x 1500mm-2500mmxL |
| Wear-resistance Steel |
NM360/400/450/500/NM300TP/400TP/450TP/ ABREX400/450/500/B-HARD450XKY/ CREUSABRO4800/8000/EH C400LE/450LE/500LE/ |
3.0-50x1250mm-3300mmxL |
| Cold Rolled Coil | DC01/RECC/REDT/SPCC/ST12 | 0.5-3.0x1250mm-1500mmxC |
| Galvanized Plate | DC51D+AZ/DC51D+Z/DX51D+Z/SGH340+Z275/Z275/Z120/S350GD+ZM275 | 0.45-3.0x1250mm-1500mmxC |
| Pickled Coil | DD11/SPHC | 2.0-6.0x1500xC |
Stainless Steel Material and Surface Specifications
| TYPE | GRADE | THICKNESS | SURFACE |
| Austenitic | 304/304H/304L/304J1 | 0.25-150mm | 2B/BA/NO.4/8K/SB/HL/NO.1 |
| Austenitic | 321 | 0.4-80mm | 2B/BA/NO.4/8K/SB/HL/NO.1 |
| Austenitic | 316/316L/317L/316Ti | 0.3-80mm | 2B/BA/NO.4/8K/SB/HL/NO.1 |
| Austenitic | 201(J1/J2/J5) | 0.35-12mm | 2B/NO.1/1D |
| Ferrite | 430 | 0.4-3.0mm | 2B/BA/NO.4/8K/SB/HL |
| Ultra Pure Ferrite | 443 | 0.4-2.0mm | 2B |
| Ultra Pure Ferrite | 436L/439/444/441 | 0.5-3.0mm | 2B/2D |
Special Steel / Nickel Base Alloy
| TYPE | GRADE | GRADE (ASTM) | GRADE (EN) | THICKNESS |
| Heat-resistant Steel | 309S | S30908 | 1.4833 | 0.5-40mm |
| Heat-resistant Steel | 310S | S31008 | 1.4845 | 0.5-40mm |
| Duplex Stainless Steel | 2101 | S32101 | 1.4162 | 1.5-50mm |
| Duplex Stainless Steel | 2304 | S32304 | 1.4362 | 3.0-50mm |
| Duplex Stainless Steel | 2205 | S32205/S31803 | 1.4462 | 0.5-60mm |
| Duplex Stainless Steel | 2507 | S32750 | 1.4410 | 1.0-60mm |
| Super Austenitic-Steel | 904L | N08904 | 1.4539 | 0.6-50mm |
| Super Austenitic-Steel | 254SMO | S31254 | 1.4547 | 0.5-50mm |
| Super Austenitic-Steel | 1.4529 | N08926 | 1.4529 | 0.5-50mm |
| Super Austenitic-Steel | AL-6XN | N08367 | 1.4478 | 0.5-50mm |
| Nickel Base Alloy | Alloy 31 | N08031 | 1.4562 | 1.0-50mm |
| Nickel Base Alloy | 800 | N08800 | 1.4876 | 0.8-50mm |
| Nickel Base Alloy | 800H | N08810 | 1.4958 | 0.8-50mm |
| Nickel Base Alloy | 800HT | N08811 | 1.4959 | 0.8-50mm |
| Nickel Base Alloy | Alloy 28 | N08028 | 1.4563 | 1.0-20mm |
| Nickel Base Alloy | Alloy 20 | N08020 | 2.4660 | 1.0-20mm |
| Nickel Base Alloy | 825 | N08825 | 2.4858 | 0.8-40mm |
| Nickel Base Alloy | C276 | N10276 | 2.4819 | 0.5-50mm |
| Nickel Base Alloy | C22 | N06022 | 2.4602 | 1.0-50mm |
| Nickel Base Alloy | 625 | N06625 | 2.4856 | 0.8-20mm |
| Nickel Base Alloy | 400 | N04400 | 2.4360 | 1.0-20mm |
| Nickel Base Alloy | 600 | N06600 | 2.4816 | 1.0-50mm |
| Nickel Base Alloy | Pure Ni 201 | N02201 | 2.4061 | 0.5-20mm |
| Titanium | TA1 | Gr.1 | Class 1 | 0.5-50mm |
| Titanium | TA2 | Gr.2 | Class 2 | 0.5-50mm |
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