What is the P number of ASME SA387 Grade22 Class 1 ?

What is the P number of ASME SA387 Grade22 Class 1 ?

ASME SA387 Grade 22, which contains ~2.25% Chromium and ~1% Molybdenum, falls under P-Number 5 according to ASME BPVC Section IX guidelines, grouping it with other low-alloy steels for welding qualification. While some tables show Grade 22 having similar specs to P5, the specific P-number assignment groups these chrome-moly steels together for welding.

Alloy steel, particularly pressure-grade steel, constitutes a common and crucial material within industrial domains. This category of steel exhibits a diverse array of specifications and standards, each tailored to specific industrial applications. Notably, these alloy steels are predominantly fashioned into finished products in the form of plates, a widely utilized format. Among the diverse grades of alloy steel, ALLOY STEEL SA 387 GR. 22 CL. 1 / 2 plates hold prominence due to their distinguished properties, rendering them highly versatile.

ASME SA387 Grade 22 Class 1 is a chromium-molybdenum alloy steel plate used for boilers and pressure vessels in high-temperature service, featuring approximately 2.25% Chromium (Cr) and 1% Molybdenum (Mo) for enhanced strength and corrosion resistance, with Class 1 indicating lower strength/higher formability than Class 2, offering good weldability and performance in hot environments (up to around 600°C) for industries like oil, gas, and petrochemicals.

Key Characteristics:

Material Type: Alloy Steel Plate.

Standard: ASME SA387 (ASTM A387).

Grade: 22 (indicating ~2.25% Cr, ~1% Mo).

Class: 1 (lower strength, better formability/weldability than Class 2).

Application: Welded boilers, pressure vessels, high-temperature service.

Properties: Excellent resistance to oxidation, corrosion, and high temperatures.

Chemical Composition (Typical for Grade 22):

Chromium (Cr): Around 2.25%.

Molybdenum (Mo): Around 1%.

Carbon (C): Lower range (e.g., 0.05-0.17% for Class 1).

Why Use It?
The chromium and molybdenum content provides superior high-temperature strength and resistance to creep, pitting, and sulfide stress cracking, making it ideal for demanding industrial environments where carbon steel would fail. Class 1 offers better ductility and ease of fabrication compared to Class 2.

What are the typical application fields of ASME SA387 Grade 22 Class 1?

ASME SA387 Grade 22 Class 1 is a chromium-molybdenum alloy steel primarily used for pressure vessels and boilers in high-temperature, high-pressure industrial environments like petrochemical, oil & gas, and power plants, serving as components for heat exchangers, piping, storage tanks, and reactors due to its excellent strength and resistance to creep, oxidation, and corrosion.

What precautions should be taken when welding ASME SA387 Grade 22 Class 1?

When welding ASME SA387 Grade 22 Class 1, key precautions involve preheating to prevent cracking, using appropriate consumables (low hydrogen), controlling heat input with stringer beads, ensuring proper ventilation and PPE, and potentially performing Post-Weld Heat Treatment (PWHT) or interpass temperature control to manage hydrogen and avoid temper embrittlement, especially for thicker sections.

What is the composition of ASME SA387 Grade 22 Class 1 ?

ASME SA387 Grade 22 Class 1 is a chromium-molybdenum alloy steel for pressure vessels, characterized by roughly 2.25% Chromium (Cr) and 1.00% Molybdenum (Mo), with maximum limits for Carbon (C), Manganese (Mn), Phosphorus (P), Sulfur (S), and Silicon (Si), designed for high-temperature service with good corrosion resistance. Key composition includes Carbon (0.05-0.15%), Manganese (0.30-0.60%), Silicon (<= 0.50%), Phosphorus (<= 0.035%), Sulfur (<= 0.035%), Chromium (2.00-2.50%), and Molybdenum (0.90-1.10%).

ASME SA387 GR 22 CLASS 1 Plate Specification :

Equivalents for ASME SA387 Grade 22 Alloy Steel Plates

Specifications for ASME SA387 Grade 22 Alloy Steel Plates

Alloy Steel ASTM A387 GR 22 CL. 1 Plates Chemical Composition :

Tensile Requirements for ASME SA387 Grade 22 Alloy Steel Plates Class 1 Plates

1What is the hardness of ASME SA387 Grade 22 Class 1 steel?

ASME SA387 Grade 22 Class 1 steel is typically supplied in an annealed condition, and while specific hardness (like Brinell or Rockwell) isn't always a primary requirement in the core spec, it's generally soft enough for good formability, often around 241 HB (Brinell) maximum for Class 2, with Class 1 being similar or softer, focusing more on yield strength (30 ksi min) and tensile strength (60-85 ksi) for boiler/pressure vessel applications, with hardness varying slightly by manufacturer and condition.

2What is the P number of ASME SA387 Grade 22 Class 1?

For ASME SA387 Grade 22 Class 1, the material falls into P-Number 5A in the ASME Boiler & Pressure Vessel Code (BPVC) Section IX, grouping it with other 2.25% Chromium-1% Molybdenum steels for elevated temperature service, which allows for qualification based on similar material groups.

3What is ASME SA387 Grade 22 Class 1 equivalent to?

ASME SA387 Grade 22 Class 1 is equivalent to ASTM A387 Grade 22 Class 1 (same material, different standard) and internationally to EN 10CrMo9-10, DIN 10CrMo9-10, and BS 622-515B, all of which are chromium-molybdenum alloy steels designed for high-temperature pressure vessel applications with slightly lower tensile strength requirements than Class 2.

4Is ASME SA387 Grade 22 Class 1 carbon steel? 

No, ASME SA387 Grade 22 Class 1 is not plain carbon steel; it's a chromium-molybdenum alloy steel, specifically a low alloy steel, used for high-temperature pressure vessels, featuring added chromium (around 2.25%) and molybdenum for strength and corrosion resistance, distinguishing it from standard carbon steels.

5What welding rod for ASME SA387 Grade 22 Class 1 ?

For welding ASME SA387 Grade 22 Class 1 (2.25% Cr, 1% Mo), you need matching or slightly over-alloyed filler metals, typically AWS A5.5 E9018-B3 (SMAW) or equivalent low-alloy flux-cored (FCAW) or gas-shielded (GMAW) consumables like AWS A5.28 ER90S-B3, ensuring post-weld heat treatment (PWHT) to prevent temper embrittlement and hydrogen cracking.

6What temperature is ASME SA387 Grade 22 Class 1?

ASME SA387 Grade 22 Class 1 is a chromium-molybdenum alloy steel used for high-temperature pressure vessels, designed to withstand elevated temperatures (often over 1000°F / 538°C) while maintaining strength, with its specified minimum tempering temperature being 1250°F (675°C) for proper heat treatment, though actual service temperatures can vary greatly depending on the application, with benefits like resistance to high-temp embrittlement.

7What is ASME SA387 Grade 22 Class 1 high speed steel?

ASME SA387 Grade 22 Class 1 isn't high-speed steel; it's a Chromium-Molybdenum (Cr-Mo) alloy steel plate for high-temperature pressure vessels and boilers, offering excellent heat/corrosion resistance due to its 2.00-2.50% Chromium and 0.90-1.10% Molybdenum content, with Class 1 denoting specific, lower tensile/yield strength requirements compared to Class 2.

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