What is ASME SA387 Grade 11 Class 1 material?

What is ASME SA387 Grade 11 Class 1 material?

ASME SA387 Grade 11 Class 1 is a weldable, low-alloy chromium-molybdenum steel plate specifically designed for high-temperature applications, commonly used in boilers, pressure vessels, and heat exchangers, offering good strength, ductility, and resistance to oxidation and corrosion, with Class 1 indicating lower tensile strength properties compared to Class 2 but higher ductility. This alloy contains roughly 1.25% chromium and 0.5% molybdenum, enhancing its performance in elevated service conditions, particularly in the oil, gas, and petrochemical industries.

ASTM A387 / ASME SA387 Grade 11 is a specification for weldable, low-alloy chromium-molybdenum steel plates specifically designed for elevated temperature service, such as in boilers, pressure vessels, and heat exchangers. This alloy contains roughly 1.25% chromium and 0.5% molybdenum, enhancing its performance in elevated service conditions, particularly in the oil, gas, and petrochemical industries. The core composition of molybdenum imparts remarkable tensile strength and impressive resistance to corrosion, while the chromium provides resistance to oxidation.

These plates are further classified into tensile Class 1 and Class 2. Class 1 indicates lower tensile strength properties compared to Class 2 but higher ductility. The annealing process, which meets Class 1 properties, "softens" the steel to enhance greater forming capabilities. Conversely, Class 2 plates are expertly crafted for deployment in steel pressure vessels operating at high temperatures and challenging environments where higher tensile strength is required.

As a dedicated supplier and proficient exporter, we provide top-tier products that adhere strictly to the guidelines of ASME SA387. Our alloy steel SA 387 GR. 11 CL. 1/2 plates are fortified to withstand extreme thermal conditions, ensuring a steadfast solution for contexts where gases and liquids endure elevated temperatures.

Key Characteristics:

Composition: Chromium (Cr) ~1.25%, Molybdenum (Mo) ~0.5%.

Purpose: For welded pressure vessels and boilers needing elevated temperature service.

Class 1 vs. Class 2: Class 1 offers lower strength but better ductility (more elongation) than Class 2, which has higher tensile and yield strength for more demanding high-stress environments.

Properties: High-temperature strength, corrosion resistance, and toughness.

Applications: Petrochemical plants, oil & gas, industrial boilers, heat exchangers, and heavy machinery components.

In essence, it's a reliable, high-quality alloy steel plate that provides essential properties for critical equipment operating under high heat and pressure, balancing strength with workable ductility

SA387 GR 11 CLASS 1  Plate Specification :

Width: 1000mm-4500mm
Thickness: 5mm to 150mm
Length: 3000mm-18000mm
Supply Condition : As Rolled, Normalized Rolling, Furnace Normalizing, Vacuum Degassing, Simulated Post-Weld Heat Treatment or as per customer requirement.
Impact tested: -52° C
Process of Manufacturing: Hot-Rolled (HR)

What is the ASME SA387 Grade11 Class1 standard?

ASME SA387 Grade 11 Class 1 is a chromium-molybdenum alloy steel plate for high-temperature pressure vessels and boilers, offering good creep, corrosion, and oxidation resistance, with lower strength but better elongation than Class 2, making it suitable for refineries and petrochemical plants in sour gas or hydrogen service.6 Key elements are ~1.25% Chromium (Cr) and ~0.5% Molybdenum (Mo), providing strength and stability for demanding environments, typically supplied normalized and tempered.

What are the typical application fields of ASME SA387 Grade 11 Class 1 steel?

ASME SA387 Grade 11 Class 1 steel is primarily used in high-temperature, high-pressure applications, especially in the oil & gas, petrochemical, and power generation industries, for equipment like pressure vessels, boilers, heat exchangers, piping, and storage tanks, benefiting from its chromium-molybdenum content for enhanced strength, creep resistance, and resistance to oxidation and corrosion, particularly in sour gas environments.

What temperature is ASME SA387 Grade 11 Class 1 steel?

In the lower end of the temperature range SA 387 Gr 11 (1150 °F min tempering temperature) , and SA 387 Gr 22 (1250 °F min tempering temperature) are used.3 These grades can be specified in either class 1 or 2 and can also be provided in the Normalized & Tempered or Quenched and Tempered.

Equivalents

Specifications for ASME SA387 Grade 11 Alloy Steel Plates

Alloy Steel ASTM A387 GR 11 CL. 1 / 2 Plates Chemical Composition :

Tensile Requirements for ASME SA387 Grade 11 Alloy Steel Plates Class 1 Plates

1 What is the hardness of ASME SA387 Grade 11 Class 1 steel?

ASME SA387 Grade 11 Class 1 steel's hardness isn't directly listed in Brinell or Rockwell scales in typical spec sheets, but its yield strength is a key indicator, around 240 MPa (35 ksi), with tensile strength between 415-585 MPa (60-85 ksi), and it's usually supplied normalized and tempered, providing good strength for elevated temperature service in pressure vessels.

2 What is ASME SA387 Grade 11 Class 1 material?

ASME SA387 Grade 11 Class 1 is a chromium-molybdenum (Cr-Mo) alloy steel plate, specified for welded boilers and pressure vessels needing high-temperature strength and corrosion resistance, common in oil, gas, and power industries, offering good oxidation/corrosion resistance, especially in sour gas

3 What is the P number of ASME SA387 Grade 11 Class 1 steel?

The P-number for ASME SA387 Grade 11 Class 1 steel is 4. this assignment applies to both Class 1 and Class 2 of Grade 11, as they share the same nominal chemical composition of 1.25Cr-0.5Mo-Si.1 This grouping identifies the material as a low-alloy steel containing chromium and molybdenum, typically used for elevated temperature service in pressure vessels.

4 What is ASME SA387 Grade 11 Class 1 equivalent to?

ASME SA387 Grade 11 Class 1 is a chromium-molybdenum alloy steel primarily used for welded boilers and pressure vessels designed for elevated temperature service.5 It is virtually identical to ASTM A387 Grade 11 Class 1, with the primary difference being the governing regulatory code.

5 What is the maximum allowable stress value for ASME SA387 Grade11 Class1?

For ASME SA387 Grade 11 Class 1, the maximum allowable stress values are determined by ASME Section II, Part D (Table 1A), and vary significantly based on the operating temperature; for instance, at a typical temperature of $650^\circ\text{F}$ ($345^\circ\text{C}$), the allowable stress is approximately 13.8 ksi (95 MPa), but this value decreases as temperatures rise toward its upper limit of $1000^\circ\text{F}$ ($538^\circ\text{C}$) to account for reduced material strength and creep resistance.

6 What precautions should be taken when welding ASME SA387 Grade 11 Class 1 steel?

When welding SA387 Grade 11 Class 1 steel (a low-alloy chromium-molybdenum steel), key precautions involve proper preheating (around 250°F/121°C minimum) to prevent cracking, selecting appropriate filler materials (like EB2 group), controlling interpass temperatures, applying Post Weld Heat Treatment (PWHT) (around 1200°F/650°C) to relieve stress, ensuring good ventilation, and using full Personal Protective Equipment (PPE), while cleaning the surface thoroughly.

7 Is ASME SA387 Grade 11 Class 1 carbon steel?

No,ASME SA387 Grade 11 Class 1 is not a carbon steel; it is a low-alloy chromium-molybdenum (Cr-Mo) steel. While it contains carbon (typically between 0.05% and 0.17%), it is specifically categorized as an alloy steel due to the intentional addition of chromium and molybdenum to enhance its performance in high-temperature and high-pressure environments.

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