Material Performance Requirements for Box Columns in Low-Temperature Environments

Low-Temperature Material Performance Requirements: Box columns must exhibit high toughness in low-temperature environments to prevent brittle fracture. The materials low-temperature toughness should be verified through Charpy impact tests. For example, Q355B steel should have an impact energy of ≥34J at -20°C. Strict control of sulfur and phosphorus content is necessary to minimize brittleness.

Optimization Measures: Employing austenitic steel or 18CrNi8 alloy steel, with their face-centered cubic structure and nickel content, can enhance low-temperature stability. During welding, shrinkage allowance should be provided, and normalizing or quenching and tempering treatment should be applied to refine the grain structure, ensuring structural reliability.