ASTM A387 Grade 11 Class 1 Steel

ASTM A387 Grade 11 Class 1 Steel

ASTM A387 grade 11 class 1 is ASTM A387 grade 11 steel in the annealed condition. ASTM A387 Gr 11 CL 1 is a chromium molybdenum alloy steel plate intended primarily for welded boiler and pressure vessels designed of elevated temperature service. The Cr content 1.25% and the Mo content 0.5%.

ASTM A387 Grade 11 Class 1 is a specific type of low-alloy pressure vessel steel primarily used in high-temperature environments. It is often referred to as "Chrome-Moly" steel because its primary alloying elements are Chromium and Molybdenum.

Here is a breakdown of what makes this grade unique:

 Key Applications

Because it maintains its structural integrity in heat, Grade 11 Class 1 is a staple in the oil, gas, and petrochemical industries. Typical uses include:

Pressure Vessels: Large tanks that hold liquids or gases at high pressure.

Heat Exchangers: Equipment designed to transfer heat between two or more fluids.

Boilers: Specifically in piping and tubing where steam is generated.

Reactors: Used in chemical processing plants.

 Comparison: Class 1 vs. Class 2

While the chemical composition is the same, the thermal processing differs:

Class 1: Lower tensile/yield strength, but higher ductility. Often chosen when the material needs significant cold-forming or when toughness is a priority.

Class 2: Higher tensile/yield strength, achieved through different heat treatment (normalization and tempering).

Welding and Fabrication

ASTM A387 Grade 11 is generally weldable, but because it is an alloy steel, it requires specific procedures to prevent cracking:

Preheating: Necessary to reduce the cooling rate and prevent hydrogen cracking.

Post-Weld Heat Treatment (PWHT): Essential to relieve internal stresses and ensure the welded joint has similar properties to the base metal.

STEEL DIMENSION:

Thickness: 6MM to 300MM,

Width: 1500mm to 4050mm,

Length: 3000mm to 15000mm

Gnee is specialized in supplying ASTM steel plate in A387 Grade11 Class1. For more information of grade A387 Gr.11 Cl.1 steel plates, please check them in following:

It is ideal for use in high-temperature and high-pressure applications such as heat exchangers, boilers, and pressure vessels.

It is also used in the construction of pipelines and storage tanks, as well as in the manufacturing of valves and other components that are exposed to high temperatures and pressures.

In summary, ASTM A387 Grade 11 is a chrome-molybdenum alloy steel that is known for its high strength and excellent corrosion resistance.

This material is commonly used in high-temperature and high-pressure applications in the oil and gas, petrochemical, and power generation industries.

With its chemical composition and mechanical properties, it is an ideal material for use in heat exchangers, boilers, and pressure vessels.

Equivalents

Dimension Range

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Width: Inquire for widths and lengths outside the noted ranges.

Specifications for ASTM A387 Grade 11 Alloy Steel Plates

Chromium & Molybdenum content (according to the ASME specification)

Mechanical Properties

Tensile testing is performed in the transverse direction.

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Tensile Requirements for ASTM A387 Grade 11 Alloy Steel Plates Class 1 Plates

1What is ASTM A387 Grade 11 Class 1?

ASTM A387 Grade 11 Class 1 is a chromium-molybdenum (Cr-Mo) alloy steel plate for high-temperature pressure vessels and boilers, containing about 1.25% Chromium and 0.5% Molybdenum for excellent strength, oxidation, creep, and hydrogen attack resistance in the oil, gas, and petrochemical industries. It offers enhanced material purity and flaw detection requirements compared to Class 2, with typical delivery in a normalized or annealed condition, suitable for severe service like reactors and hydrogenation vessels.

2What is ASTM A387 Grade 11 Class 1 equivalent to?

ASTM A387 Grade 11 Class 1 is directly equivalent to ASME SA387 Grade 11 Class 1, sharing the same composition (1.25% Cr, 0.50% Mo) and properties, with ASME being the boiler & pressure vessel code version for similar high-temperature service; it also has a British equivalent, BS 621B, though EN/DIN standards differ, with EN 13CrMoSi5-5 being a related European grade.

3What temperature is ASTM A387 Grade 11 Class 1 ?

ASTM A387 Grade 11 Class 1 is a chromium-molybdenum steel for high-temperature pressure vessels, suitable for service in the 350°C to 480°C (660°F to 900°F) range, with its actual use temperature dependent on design codes like ASME, which lists limits around 40°F to 375°F (4°C to 190°C) for allowable stresses, but it's designed for much higher service. Key temperatures include a minimum 1150°F (620°C) tempering and specified impact test temperatures like -20°C, -40°C, or -60°C, depending on thickness.

4What are the typical application fields of ASTM A387 Grade 11 Class 1 ?

ASTM A387 Grade 11 Class 1 is a chromium-molybdenum alloy steel primarily used in pressure vessels, boilers, and heat exchangers for applications requiring high-temperature strength, creep, and corrosion resistance, especially in the oil & gas, petrochemical, refining, and power generation industries. Its common uses extend to piping, storage tanks, and reactors in demanding thermal environments, including sour gas service.

5What is the composition of ASTM A387 Grade 11 Class 1 ?

ASTM A387 Grade 11 Class 1 is a chromium-molybdenum alloy steel for pressure vessels, featuring key elements like ~1.25% Chromium (Cr) and ~0.5% Molybdenum (Mo) for high-temp strength and corrosion resistance, with specific ranges for Carbon (C, ~0.05-0.17%), Manganese (Mn, ~0.35-0.73%), Silicon (Si, ~0.44-0.86%), Phosphorus (P, max 0.035%), and Sulfur (S, max 0.035%)

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Request a professional quotation for ASTM A387 grade 11 class 1 from GNEE Steel. Email info@gneesteels.com.