Global Steel Structure Projects
At Deyu, every project follows a strict manufacturing specification. Production flows from raw material verification and precision cutting to multi-stage welding control, corrosion protection, and final pre-shipment inspection.
Our facilities process prefabricated steel structures and steel bridges for industrial buildings, logistics warehouses, infrastructure, pedestrian bridges, and highway systems in compliance with engineering requirements.
Material Verification & Traceability
Incoming Material Standards
Production begins with material verification against international specifications. Each batch is tracked via production records linking source steel to finished components.
Inspections:
- Steel grade verification
- Chemical composition analysis
- Mechanical property testing (tensile and yield strength)
- Thickness and dimensional measurement
- Surface defect inspection
- Mill test certificate (MTC) verification
Material Grades:
- Carbon structural steel (e.g., Q355B / ASTM A572 Gr.50)
- High-strength low-alloy steel
- Weather-resistant structural steel
- Hot-dip galvanized steel components
Engineering Design & Calculation
Structural Engineering Parameters
Engineering parameters are calculated based on project location, structural load requirements, and applicable design standards.
Load & Safety Calculations:
Dead load and live load capacity
Wind load and snow load analysis
Seismic resistance design parameters
Fatigue analysis for bridge structures
Fabrication Detailing:
Connection node design
Component optimization for transport and erection tolerances
Detailed fabrication and assembly drawings
Manufacturing & Fabrication Control
CNC Processing & Assembly Tolerances
Fabrication relies on standardized CNC operations to maintain dimensional accuracy across structural elements.
Cutting & Forming:
- CNC plasma and laser cutting for plate edge preparation
- Automated drilling and milling for bolt hole positioning
- Cold-forming and cambering control for beams
Welding Execution:
- Pre-qualified welding procedure specifications (WPS)
- Certified welding personnel (AWS / ISO qualified)
- In-process parameter monitoring (voltage, amperage, travel speed)
Non-Destructive Testing (NDT):
- Ultrasonic Testing (UT) for full-penetration butt welds
- Magnetic Particle Testing (MT) for fillet welds
- Dye Penetrant Testing (PT) for surface discontinuity checks
Dimensional Inspection:
- Verification of overall length, camber, and squareness
- Bolt hole pitch and edge distance measurement
- Trial assembly of complex bridge segments and truss joints prior to dispatch
Surface Treatment & Corrosion Protection
Coating Systems & Galvanization
Corrosion protection specifications are tailored to operational environments and service life requirements.
Surface Preparation:
- Abrasive shot blasting to Sa 2.5 cleanliness standard
- Surface profile depth control for coating mechanical keying
Coating Applications:
- Multi-layer paint systems (Epoxy zinc-rich primer, epoxy intermediate, polyurethane or fluorocarbon topcoat)
- Dry film thickness (DFT) verification per layer
Hot-Dip Galvanizing:
- Immersion in molten zinc baths per ASTM A123 / ISO 1461
- Coating weight and uniformity checks for outdoor and coastal environments
Pre-Shipment Inspection & Documentation
Factory Acceptance & Deliverables
Final inspections verify conformity prior to packaging and transport.
Verification Items:
- Dimensional check against approved shop drawings
- Component identification marking and barcode tracking
- Surface coating integrity and hardware matching
Documentation Package:
- Mill test certificates and material traceability reports
- NDT inspection reports (UT/MT/PT)
- Dimension inspection and trial assembly records
- Surface treatment and coating thickness reports
- Packing lists and shipping documentation
International Standards Compliance
Governing Codes & Standards
Manufacturing procedures align with regional and international engineering standards:
Structural Design & Fabrication:
EN Eurocode Standards
AISC Steel Construction Standards
ASTM Material Standards
GB/T Chinese National Standards
Welding Codes:
AWS D1.1 Structural Welding Code - Steel
EN ISO Structural Welding Standards
Bridge Specifications:
AASHTO LRFD Bridge Design Specifications
EN Bridge Execution Standards
Factory Certifications
Quality Management & System Audits
Manufacturing facilities operate under audited management systems:
ISO 9001: Quality Management System (standardized production and traceability controls)
ISO 14001: Environmental Management System (waste and emission control protocols)
ISO 45001: Occupational Health and Safety Management System (workplace safety standards)
EN 1090: Execution of Steel Structures and Aluminium Structures (Factory Production Control for the European market)
AWS Certification: Structural welding fabrication qualification
Manufacturing Workflow
- Material Inspection
- Engineering Review
- CNC Cutting & Forming
- Component Fabrication
- Welding & NDT Inspection
- Surface Treatment
- Trial Assembly
- Final Inspection & Packaging
Project Inquiry & Technical Submission
To request technical specifications, material compliance reviews, or project-specific fabrication estimates, submit drawings and engineering requirements to our technical team.