Application Fields of GB6653 HP325 Steel
GB6653 HP325 steel is a low-alloy high-strength structural steel specifically designed for welded gas cylinders, primarily used in the manufacture of liquefied petroleum gas (LPG) cylinders, oxygen cylinders, fire extinguishers, gas tanks, and other pressure-bearing equipment.
1. LPG Cylinder Manufacturing
Typical Application: HP325 steel serves as the primary material for manufacturing YSP-50 liquefied petroleum gas cylinders (with a maximum filling capacity of 50 kg), widely utilized in canteens, restaurants, hotels, and other high-gas-consumption settings.
Performance Requirements:
Strength and Toughness: With a tensile strength of 490–600 MPa and a yield strength ≥325 MPa, it ensures no plastic deformation occurs under high-pressure gas (typically above 2.1 MPa).
Low-Temperature Toughness: Must pass environmental temperature tests ranging from -40°C to 60°C to adapt to extreme climatic conditions.
Weldability: Features a low carbon equivalent (Ceq ≤ 0.4%) and a low welding cold cracking sensitivity index (Pcm), supporting preheat-free welding processes and reducing production costs.
Process Adaptability: Hot-rolled steel plates must undergo stringent hydrostatic testing, airtightness testing, and weld X-ray inspections to ensure no leakage risks.
2. Industrial Gas Storage Containers
Application Scenarios: Oxygen cylinders, nitrogen cylinders, carbon dioxide cylinders, and other industrial gas storage equipment.
Performance Support:
High Strength: Sustains long-term storage of high-pressure gases, preventing container deformation.
Fatigue Resistance: Grain refinement through normalizing processes enhances fatigue life under dynamic loads, accommodating frequent filling and usage scenarios.
Corrosion Resistance: Aluminum content (Alt ≥ 0.015%) fixes nitrogen elements, reducing corrosion risks in welded joints and extending service life.
3. Firefighting Equipment Sector
Core Application: Fire extinguisher cylinders (e.g., dry powder extinguishers, carbon dioxide extinguishers).
Key Characteristics:
Lightweight Design: High strength allows for reduced wall thickness, lowering equipment weight for easier handling and operation.
Safety: Bending tests (180° bending with a punch diameter D = 2.0a) validate forming process adaptability, ensuring no cracks occur under high pressure.
Cost Efficiency: Smelting processes control sulfur (≤0.025%) and phosphorus (≤0.012%) content, minimizing impurities and reducing production costs.
4. Other Pressure-Bearing Equipment
Expanded Applications: Certain low-pressure boilers, high-pressure vessels, and other scenarios requiring a balance of strength and toughness.
Technical Advantages:
Purity Control: Techniques such as KR desulfurization (≤0.002%) and RH vacuum degassing (hydrogen ≤ 1.5 ppm) reduce inclusions and enhance material uniformity.
Microstructure Optimization: A ferrite + pearlite microstructure with a grain size of 10.0–12.0 balances strength and plastic deformation capacity.
