Structural Engineering Steel: High-Performance Materials for Modern Construction

Key Steel Grades for Structural Engineering

1. High-Strength Low-Alloy (HSLA) Steels

• Q355/Q460: Ideal for seismic-resistant structures

• ASTM A572 Gr. 50/60: US standard for bridges and towers

• S355/S460: European equivalents with strict impact testing

2. Weathering Steels

• Q355NH/Q460NH: Forms protective rust layer

• ASTM A588: For bridges and outdoor structures

• Corten alternatives: 4-8x better corrosion resistance

3. Earthquake-Resistant Steels

• Q345GJ: Chinese seismic grade

• SN490: Japanese earthquake standards

• Special requirements: Low yield ratio (<0.8)

Technical Properties Comparison

Critical Applications

1. High-Rise Buildings

• Core wall construction

• Outrigger trusses

• Transfer structures

2. Long-Span Bridges

• Box girder components

• Cable-stayed bridge pylons

• Expansion joints

3. Industrial Facilities

• Heavy crane runways

• Process plant structures

• Power generation units

Quality Assurance & Testing

✔ Chemical Analysis: Optical emission spectrometry
✔ Mechanical Testing: Tensile, impact, bend tests
✔ NDT Methods: UT, MT, PT, RT as required
✔ Certifications: EN 10204 3.1/3.2, mill certificates

Project Example:
Seismic-Resistant Hospital in Philippines

• Steel Grade: Q345GJC (Chinese seismic standard)

• Special Requirements: Z35 through-thickness performance

• Quantity: 5,800 tons

• Compliance: GB 50011-2010 seismic code

Fabrication Considerations

⚠ Special Processing Requirements:

• Welding: Preheat requirements for thick sections

• Cutting: Laser/plasma for high-strength grades

• Forming: Minimum bend radii 3× thickness

• Protection: Thermal spray aluminum for marine environments

Why Choose Liyou for Structural Steel?

✅ Direct Mill Partnerships with Baowu/Ansteel
✅ Technical Support for material selection
✅ Just-in-Time Inventory of specialty grades
✅ Global Logistics to project sites worldwide