A387 Grade 11 Class 2 is a high-quality chromium-molybdenum (Cr-Mo) alloy steel plate, specified by ASTM/ASME standards, designed for pressure vessels and boilers operating at high temperatures, offering excellent creep strength, oxidation resistance, and weldability.
A387 Gr.11 CL.2Chemical Composition | |||||||
Grade | The Element Max (%) | ||||||
| C | Si | Mn | P | S | Cr | Mo |
A387 Gr.11 Cl.2 | 0.04-0.17 | 0.44-0.86 | 0.35-0.73 | 0.035 | 0.035 | 0.94-1.56 | 0.40-0.70 |
Grade | A387 Gr.11 CL.2Mechanical Property | |||
| Thickness | Yield | Tensile | Elongation |
A387 Gr.11 Cl.2 | mm | Min Mpa | Mpa | Min % |
| t≦50 | 310 | 515-690 | 18 |
50<t≦200 | - | - | - | |
Advantages
High-Temperature Performance: Maintains strength and integrity at elevated temperatures, resisting creep and thermal stress.
Corrosion & Oxidation Resistance: Chromium content provides excellent resistance to oxidation and corrosion, crucial in harsh environments.
Hydrogen Attack Resistance: Alloy composition offers better resistance to hydrogen-induced damage than carbon steels.
Superior Mechanical Properties (Class 2): Higher yield and tensile strength, greater hardness, and improved stability after heat treatment (normalized & tempered) compared to Class 1.
Enhanced Safety & Reliability: Provides a higher safety margin for long-term, continuous operation in extreme conditions.
Good Weldability: Can be welded effectively for fabricating complex pressure vessel components.
Applications
Oil & Gas/Petrochemical Industry
This material is ideal for sour (hydrogen sulfide) environments, used to fabricate hydrotreating/hydrocracking reactors, fractionating columns, gas-liquid separators, and storage vessels. It resists hydrogen sulfide corrosion and high-temperature hydrogen attack, withstanding pressures up to 20 MPa and temperatures exceeding 400°C to prevent sulfide stress cracking.
Power Generation Industry
In thermal power plants, it is critical for boiler systems: applied to boiler drums (steam-water separation under 540°C/10 MPa), headers (fluid distribution), and pressure parts like main steam pipes. It resists creep deformation, thermal cycling, and oxidation to ensure system efficiency and safety.
General Industry
It suits heat exchangers, high-temperature process piping, and welded boilers across chemical, pharmaceutical, and metallurgical sectors. It delivers robust strength, excellent weldability, and stable performance under sustained high-temperature and high-pressure conditions for critical equipment.
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What is A387 Grade 11 CL 2 equivalent to?
ASTM A387 grade 11 covers A387 grade 11 class 1 and A387 grade 11 class 2, which are equivalent to ASME SA387 grade 11 class 1 and SA387 grade 11 class 2 respectively. ASTM A387 grade 11 equivalent steel has similiar properties and performance to A387 grade 11 steel.
What is A387 Grade 11 CL 2 material?
A387 Grade 11 Class 2 material is a chromium-molybdenum alloy steel plate (ASTM A/SA 387) designed for high-temperature and high-pressure applications, especially pressure vessels, boilers, and heat exchangers, offering excellent resistance to oxidation and corrosion due to its ~1% Chromium (Cr) and ~0.5% Molybdenum (Mo) content, with 'Class 2' indicating enhanced mechanical properties like higher tensile/yield strength compared to Class 1.}