Factors affecting the price of SA 387 GR 11 steel plates
SA387 Grade 11 Class 1 is an ASME/ASTM chromium-molybdenum alloy steel plate, specified for high-temperature pressure vessels and boilers, offering good corrosion/oxidation resistance due to its ~1% Chromium and ~0.5% Molybdenum content, with Class 1 indicating a lower tensile strength level compared to Class 2. It's used in the oil, gas, and chemical industries for tanks and piping requiring strength at elevated temperatures and in sour (H2S) environments, providing improved tensile strength, temperature resistance, and anti-rust properties.
Providing a specific, real-time price for SA 387 Grade 11 plate is not possible, as steel prices are highly dynamic and fluctuate based on numerous market and project-specific factors. However, I can explain the key variables that determine the cost and provide a framework for obtaining an accurate quote.
Key Factors Influencing Price:
Market Conditions (Biggest Driver):
Raw Material Costs: Prices for iron ore, scrap metal, and energy (especially crucial for alloy steel production) change daily.
Global Demand/Supply: Industrial activity in key sectors (energy, petrochemicals) and global trade flows significantly impact plate prices.
Alloy Surcharges: As a chromium-molybdenum alloy, the cost is heavily affected by the market prices of Chromium (Cr) and Molybdenum (Mo). These surcharges can be substantial and are updated monthly by mills.
Material Specifications:
Class: Class 2 (Normalized & Tempered) is more common and often less expensive than Class 1 (Annealed) for standard inventories.
Size & Quantity: Thickness, width, length, and total order weight dramatically affect the unit price. Mill-ordered quantities (e.g., full heat, 20+ tons) are far cheaper per kg than small, cut-to-size pieces from a service center.
Test Requirements: Additional testing beyond standard certification (e.g., impact testing at low temperature, enhanced ultrasonic testing (UT) to A578 Level) adds cost.
Procurement Source:
Mill Direct (e.g., ArcelorMittal, SSAB, Dillinger): Best for large, project-based orders. Long lead times.
Steel Service Center / Stockist: Best for smaller quantities, faster delivery, but at a premium.
Origin: Domestic (e.g., US, EU) production typically costs more than imports (e.g., from India, China), but includes fewer logistics/lead time risks and may comply with local "Buy America" acts.
Price Estimate Framework (for Budgeting):
As a very rough budgetary benchmark (as of recent market conditions, subject to change):
Base Plate Cost: The raw "commodity" price for carbon steel plate.
Alloy Surcharge: A significant adder for Cr-Mo content. This can often double or triple the base cost.
Typical Range: The total cost for SA387 Gr.11 plate often falls within a range of $2,500 to $4,500 USD per metric ton (or $1.15 to $2.00 per pound), depending heavily on the above factors.
Example: A small-order, cut piece of 1" thick plate from a service center may cost $4,500/ton, while a large mill order for 50mm thick plate might be $2,800/ton.
How to Get an Accurate Quote:
To obtain a valid price, you must provide suppliers with a complete request for quotation (RFQ) including:
Full Designation: ASTM/ASME SA387 Grade 11, specify Class 1 or Class 2.
Dimensions: Thickness (mm or in), Width (mm or in), Length (mm or in).
Quantity: Total weight (kg or lbs) or number of plates.
Heat Treatment: "Normalized & Tempered" (for Cl. 2) or "Annealed" (for Cl. 1).
Certification: Standard Mill Test Certificate (MTC) per EN 10204 Type 3.1 or 3.2.
Additional Requirements: Impact testing (temperature, energy), NDE (UT level), special marking.
Destination: Delivery location (port, job site).
Recommendation: Contact 3-4 reputable steel service centers or mills with your detailed RFQ for competitive, current market pricing. Always confirm that the material will be supplied with the proper ASME SA-387 certification if it's for a code pressure vessel.
1. How Does The Chemical Composition Of A387 Grade 5 Differ From Grade 11 Or Grade 12?
A387 Grade 5 is a higher-chromium alloy steel, typically containing around 5% chromium and 0.5% molybdenum. This places it between the more common Grade 11 (~1.25% Cr) and Grade 22 (~2.25% Cr), giving it distinct advantages in terms of oxidation resistance and elevated-temperature strength compared to lower-alloy grades, while potentially being more cost-effective than higher-chromium steels for specific service ranges.
2. What Are The Primary High-Temperature Service Advantages Of Using Grade 5 Class 2?
The primary advantage of A387 Grade 5 Class 2 lies in its superior oxidation resistance and higher strength retention at temperatures typically ranging from 540°C to 600°C (1000°F to 1112°F), exceeding the capability of Grade 11 or 12. This makes it suitable for components in catalytic crackers, reformer furnaces, and other severe petrochemical service environments where scaling and creep are significant concerns.
3. What Are The Critical Welding And Fabrication Considerations For A387 Gr.5 Cl.2?
Welding A387 Grade 5 Class 2 requires stringent procedures due to its higher alloy content. It demands mandatory preheating (usually 175-250°C / 350-480°F) and strict interpass temperature control to prevent hard, crack-sensitive microstructures. Furthermore, a mandatory Post-Weld Heat Treatment (PWHT) in the range of 675-730°C (1250-1350°F) is essential to temper the weld zone, relieve stresses, and restore corrosion resistance.
4. What Is The Standard Heat Treatment Condition For A387 Grade 5 Class 2 Plates?
A387 Grade 5 Class 2 plates are supplied in the Normalized and Tempered condition. Normalizing involves heating above the transformation range and air cooling to refine the grain structure, followed by tempering at a sub-critical temperature to achieve the optimal combination of strength and ductility specified in the standard (typically a minimum yield strength of 310 MPa / 45 ksi).
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
