ASME SA387 Grade 11 Class 2 is a widely recognized chromium‑molybdenum (Cr‑Mo) alloy heat-resistant steel plate established under the ASME Boiler and Pressure Vessel Code. It is engineered to sustain stable mechanical properties and structural integrity during long-term service under high-temperature, high-pressure and mild corrosive conditions. Ordinary carbon steel tends to suffer creep deformation, oxidation failure and strength degradation at elevated temperatures. By contrast, ASME SA387 Grade 11 Class 2 hot-rolled steel plate possesses favorable high-temperature stability, outstanding thermal fatigue resistance and dependable weldability. It serves as the preferred structural material for high-temperature pressure vessels, boilers, heat exchangers and reaction towers across petrochemical, thermal power, coal chemical and energy sectors.
As a professional supplier of ASME-compliant heat-resistant steel plates, GNEE Steel addresses customers' core demands for consistent quality, reliable lead times, technical support and one-stop solutions. We deliver full-lifecycle supporting services for SA387 Grade 11 Class 2 products to tackle diverse challenges in material selection, procurement and after-sales phases.
High-Temperature Heat Resistance Mechanism of ASME SA387 Grade 11 Cl.2 Alloy Steel Plate
The core strength of ASME SA387 Grade 11 Class 2 alloy steel plate is its exceptional comprehensive heat resistance, which mitigates common failure risks of conventional steels under high-temperature service conditions. Its heat resistance manifests in three core dimensions, supporting long-term safe operation within the 350°C–540°C temperature window.
Excellent High-Temperature Creep Resistance
Creep failure is the leading cause of decommissioning for high-temperature equipment. Under sustained high-temperature and high-pressure conditions, conventional steel experiences progressive plastic deformation, which ultimately leads to cracking. The 1.25Cr‑0.5Mo alloy composition of ASME SA387 Grade 11 Cl.2 chromium‑molybdenum plate preserves stable grain boundary strength at elevated temperatures, significantly slowing creep deformation. ASME SA387 Grade 11 Class 2 chromium‑molybdenum plate maintains steady creep strength for more than 100,000 hours under operating conditions of 500°C and 12 MPa.
Superior High-Temperature Oxidation Resistance
Below 540°C, chromium contained in Grade 11 plate automatically generates a dense, strongly adherent Cr₂O₃ oxide scale. This barrier isolates the steel substrate from air and corrosive media to halt continuous oxidation and scaling, preventing equipment wall thinning and medium leakage triggered by high-temperature oxidation. Its high-temperature oxidation resistance exceeds that of conventional boiler steels including Q245R by over three times.
Stable Thermal Fatigue Resistance
Industrial equipment often undergoes frequent start-stop cycles and temperature fluctuations. Hot-rolled ASME SA387 Grade 11 Class 2 steel plate possesses a low coefficient of thermal expansion and outstanding microstructural stability. It resists thermal stress shocks generated by rapid temperature swings and effectively avoids fatigue cracking in equipment base metal and welds.
ASME SA387 Grade 11 Class 2 Pressure Vessel Steel Plate Chemical Composition
| Element | Chemical Composition (%) | |
| SA387 Grade 11 | ||
| Carbon: | Heat Analysis: | 0.05 - 0.17 |
| Product Analysis: | 0.04 - 0.17 | |
| Manganese: | Heat Analysis: | 0.40 - 0.65 |
| Product Analysis: | 0.35 - 0.73 | |
| Phosphorus: | Heat Analysis: | 0.025 |
| Product Analysis: | 0.025 | |
| Sulfur (max): | Heat Analysis: | 0.025 |
| Product Analysis: | 0.025 | |
| Silicon: | Heat Analysis: | 0.50 - 0.80 |
| Product Analysis: | 0.44 - 0.86 | |
| Chromium: | Heat Analysis: | 1.00 - 1.50 |
| Product Analysis: | 0.94 - 1.56 | |
| Molybdenum: | Heat Analysis: | 0.45 - 0.65 |
| Product Analysis: | 0.45 - 0.70 |
ASME SA387 Grade 11 Class 2 Heat-Resistant PVQ Steel Plate Mechanical Property
| Designation: | Requirement: | Grade 11 |
| SA387 Grade 11 | Tensile strength, ksi [MPa] | 75 to 100 [515 to 690] |
| Yield strength, min, ksi [MPa]/(0.2% offset) | 43 [310] | |
| Elongation in 8 in. [200mm], min % | 18 | |
| Elongation in 2 in. [50mm], min, % | 22 |
ASME SA387 Grade 11 Class 2 Hot Rolled Chrome Molybdenum Steel Plate Specification
| Standard: ASTM A387/ASME SA387 Grade : A387 Grade 11 Class 2. |
| Thickness : 8mm-250mm Width : 1500mm-4200mm Length : 3000mm-18000mm, Customizable upon request |
| MOQ: 1 PC Product type : Steel plate Delivery time : Promptly ( Stock) or 10-40 days (Production) Payment Terms: L/C, T/T, etc Stock : Available MTC: Available |
| Delivery condition: Q+T |
| MTC: Original |
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Typical Applications of ASME SA387 Grade 11 Class 2 Heat-Resistant Steel Plate
ASME SA387 Grade 11 Class 2 Plate for Petrochemical Hydrogenation Equipment
Mainly used for shells of hydrogenation reactors, hot high-pressure separators and reforming towers. These equipment units operate between 400–520°C and are exposed to hydrogen-rich corrosive media. ASME SA387 Grade 11 Class 2 chromium‑molybdenum steel plate offers superior resistance to high-temperature oxidation and hydrogen embrittlement, effectively inhibiting equipment scaling and internal corrosion. Its favorable creep stability ensures long-term safe operation under high pressure and prevents unplanned shutdown maintenance caused by material failure.
ASME SA387 Grade 11 Class 2 Plate for Thermal Power Plant Boilers and Steam Systems
Applied to boiler steam drums, superheater headers and main steam pipelines. Long-term erosion by high-temperature steam (450–510°C) easily leads to material aging and spalling. Hot-rolled ASME SA387 Grade 11 Class 2 plates maintain stable tensile strength and oxidation resistance under repeated steam temperature cycling, reducing pipeline leakage and boiler scaling and enhancing operational stability of power generation equipment.
ASME SA387 Grade 11 Class 2 Plate for Coal Chemical and Ammonia Synthesis Equipment
Utilized for coal gasification pressure vessels and ammonia synthesis reaction towers. The service environment features high temperature, high pressure and complex acid and alkaline media. Hot-rolled ASME SA387 Grade 11 Class 2 steel plate exhibits excellent thermal fatigue resistance to adapt to frequent start-stop operations, preventing fatigue cracking induced by thermal stress and supporting continuous stable production of chemical enterprises.
ASME SA387 Grade 11 Class 2 Plate for Industrial High-Temperature Heat Exchangers
Deployed for shells and heat transfer plates of high-temperature heat exchangers in chemical and energy industries. Thanks to its low coefficient of thermal expansion and high-temperature structural stability, ASME SA387 Grade 11 Class 2 chromium‑molybdenum plate avoids deformation and structural loosening under long-term alternating hot and cold service conditions, sustaining efficient and stable heat exchange performance.
ASME SA387 Grade 11 Class 2 Plate for High-Temperature Storage and Pressure Buffer Equipment
Applicable to high-temperature medium storage tanks and pressure buffer tanks in refineries. Hot-rolled ASME SA387 Grade 11 Class 2 plate provides balanced high-temperature mechanical properties to prevent bulging or deformation during prolonged high-temperature pressurized service, and meets safety requirements for ASME-compliant pressure vessels.
Why Choose Our ASME SA387 Grade 11 Class 2 PVQ plate?
All SA387 Gr.11 Cl.2 steel plates from GNEE Steel are manufactured strictly in compliance with ASME standards. 100% ultrasonic non-destructive testing is carried out, together with comprehensive sampling tests for chemical composition and mechanical properties. We provide official Material Test Reports (MTR), ASME certification documents and third-party inspection reports from SGS and CCS, ensuring a 100% project acceptance rate. The qualified product rate remains steadily at 99.8%.
Cutting, flattening, polishing, beveling and heat treatment services are offered based on customer drawings. We can fabricate non-standard plates with special thicknesses and widths, helping customers cut secondary fabrication expenses and shorten project lead times. Machining dimensional tolerance is controlled within ±0.1 mm.
GNEE Steel holds substantial inventory of SA387 Gr.11 Cl.2 heat-resistant steel plates in standard sizes for prompt shipment. For tailor-made special specifications, we guarantee minimized production lead times and avoid project delays stemming from material shortages.
Professional waterproof, anti-corrosion and shock-resistant packaging is applied to protect plates against deformation, corrosion and damage in transit. Diverse transport solutions and door-to-door delivery are available to ensure products arrive in good condition.
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FAQ
Q: What are the equivalent materials for SA387 Gr.11 plate?
A: Equivalent materials for ASME SA387 Grade 11 plate include ASTM A387 Grade 11, European EN 10028-2 grade 13CrMoSi5-5 (or 1.7335 / 13CrMo4-5 variants), and British Standard BS 1501-620 / 621B.
Q: What are the machining characteristics of SA387 Gr.11 steel plate?
A: SA387 Gr.11 steel plate features moderate machinability, good weldability, and high tensile strength. It is a chromium-molybdenum low-alloy steel (1.25% Cr, 0.5% Mo) designed for elevated temperature service.
Q: Which has better ductility: SA387 Gr.11 Class 1 or Class 2?
A: SA387 Grade 11 Class 1 has better ductility than Class 2, featuring higher elongation values because it is processed for lower strength requirements.
Q: What is the density of SA387 Gr.11 plate?
A: The density of ASME SA387 Grade 11 alloy steel plate is approximately 7.85 g/cm³ (7850 kg/m³ or 0.284 lb/in³), which is standard for carbon and low-alloy chromium-molybdenum steels.
