ASTM A387 Grade 22 Class 1 is a chromium-molybdenum alloy steel plate primarily used for welded pressure vessels. Known for its well-balanced high-temperature strength, corrosion resistance, and weldability, it is widely applied in the manufacturing of high-temperature and high-pressure pressure vessels and boilers in sectors such as petrochemical, power, and nuclear power.

Key Features and Advantages

Excellent High-Temperature Strength: Maintains good creep resistance and strength in the range of 500-580°C, suitable for long-term high-temperature service.

Good Oxidation Resistance: The chromium content enables resistance to corrosion from water vapor, air, and other oxidizing atmospheres.

Strong Resistance to Hydrogen Corrosion: Suitable for petrochemical applications, it resists hydrogen attack in high-temperature, high-pressure hydrogen environments.

Good Weldability: As a low-alloy steel with well-controlled carbon content, it offers favorable weldability. However, strict welding procedures must be followed, typically requiring preheating and post-weld heat treatment.

ASTM A387 Grade 22 Class 1 (A387GR22CL1) steel plates are primarily used in the manufacturing of pressure vessels and equipment operating in high-temperature and/or corrosive environments, such as:

1. Petroleum refining equipment: Hydrocracking reactors, catalytic cracking units, high-temperature and high-pressure separators.

2. Coal chemical equipment: Coal gasification reactors.

3. Thermal power plants: High-pressure boiler components (such as steam drums), high-temperature steam pipelines.

4. Chemical equipment: Ammonia synthesis converters, methanol synthesis converters, etc.

Welding Precautions

Preheating before welding: The recommended preheating temperature is 150-200°C to reduce the tendency for hardening.

Welding material selection: Use electrodes (e.g., E9018-B3) or welding wires that match the 2.25Cr-1Mo composition to ensure weld strength and corrosion resistance.

Post-weld heat treatment (PWHT): Soaking at 677-760°C is required to eliminate residual welding stress.

Machining Precautions

Cold working: Avoid excessive deformation; perform intermediate annealing if necessary.

Hot working: Control the heating temperature between 900-1100°C to prevent grain coarsening.