Alloy Steel Pressure Vessel Steel Plates A302 GR. B

1.What are the chemical composition of A302 Grade B pressure vessel?

2.What are the characteristic advantages of A302 Grade B?

High Strength and Toughness

• Provides elevated tensile strength (typically 485–620 MPa / 70–90 ksi) and yield strength (≥275 MPa / 40 ksi), making it suitable for moderate-to-high pressure systems.
• Molybdenum (Mo) in its composition enhances resistance to creep and fatigue at elevated temperatures, ensuring structural integrity in medium-high temperature environments (e.g., up to 480°C / 900°F).

Excellent Impact Resistance

• Exhibits good notch toughness and impact resistance at ambient and slightly sub-zero temperatures (e.g., ≥27 J Charpy V-notch at room temperature), reducing the risk of brittle fracture in dynamic or fluctuating load conditions.

Weldability and Formability

• Generally compatible with common welding processes (e.g., SMAW, GTAW) when proper preheating and post-weld heat treatment (PWHT) are applied, facilitating the fabrication of complex vessel structures.
• Maintains ductility during forming operations, allowing for bending or rolling into cylindrical or spherical shapes without significant loss of mechanical properties.

Corrosion and Hydrogen Resistance

• Molybdenum improves resistance to hydrogen-induced cracking (HIC) and sulfide stress corrosion (SSC) in environments involving hydrogen or sulfur-containing media (e.g., petrochemical refining).
• Offers better oxidation resistance than carbon steel at elevated temperatures, extending service life in high-temperature corrosive applications.

Cost-Effective High-Temperature Performance

• Balances alloy content (manganese + molybdenum) to provide reliable high-temperature strength at a lower cost than nickel-based or higher-alloy steels (e.g., A203 or A204), making it suitable for industrial applications like boilers, heat exchangers, and pressure vessels in power generation and oil/gas sectors.

3.What are the typical applications of A302 Grade B?

• Boilers and steam drums
• Pressure vessels in petrochemical and chemical processing
• High-pressure pipelines and storage tanks
• Components requiring moderate heat and pressure resistance

4.What is the equivalent of A302 Grade B?