Seamless Steel Structure Bridge

Category：

Steel Structure Bridge
Browse number：

8
Release time：

2025-03-22 14:37:41
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Detailed Description

1、 Core advantages of seamless steel bridges

Zero weld defects

Seamless steel pipes are integrally formed through hot rolling or cold drawing processes, without any weld heat affected zone, completely eliminating the risk of cracks and porosity in traditional welded steel pipes, and increasing fatigue life by more than 50% (ASTM E466 standard).

Ultra high strength and lightweight

High strength steels such as Q460D and Q690E are used, with a yield strength of 460-690MPa. Under the same bearing capacity, the wall thickness is reduced by 20%, and the self weight of the bridge is reduced by 30%;

Typical application: The main chord tube of a large-span arch bridge (Φ 1200 × 30mm) has a single tube axial compressive bearing capacity of ≥ 50000kN.

Extreme environmental adaptability

Low temperature toughness: -60 ℃ impact energy ≥ 80J (09MnNiDR material), suitable for bridges in high-altitude areas;

Corrosion resistance: Salt spray test ≥ 15000 hours (hot-dip galvanizing+fluorocarbon coating), service life ≥ 100 years in marine environment.

Excellent fluid mechanics performance

The inner wall smoothness Ra is ≤ 0.4 μ m (cold drawing finishing process), and the fluid resistance is reduced by 20% compared to welded pipes. It is suitable for water transmission bridges and oil and gas pipeline bridges.

2、 Core product series and technical parameters

Product Type	Specifications and materials	Key technical indicators	Applicable scenarios
Seamless steel pipe arch rib	Φ800-Φ1500×20-40mm Q460D	Arrow span ratio of 1/4-1/5, bearing capacity ≥ 35000kN	Long span arch bridge, basket arch bridge
Seamless steel box girder	Single box three chamber section, plate thickness 14-30mm Q345qD	Anti torsion stiffness ≥ 2 × 10 ^ 6 kN · m ²/rad	Cable stayed bridge, suspension bridge stiffening beam
Seamless steel pipe truss	Φ 300- Φ 600 × 10-20mm Q420E, N-type truss	Node plate bolt hole group positioning accuracy ± 0.3mm	Public railway dual-use bridge, overpass bridge
Seamless steel cable tower	Φ 1200 × 25mm Q390GJC, filled with C60 concrete	Tower top offset ≤ H/3000 (H is tower height)	Tower columns of cable-stayed bridges and suspension bridges
Seamless water pipeline bridge	Φ 2000 × 25mm X65 pipeline steel, lined with epoxy coating	Working pressure ≤ 10MPa, flow rate ≥ 50m ³/s	River crossing water/oil and gas pipeline bridge

3、 Key Manufacturing Technologies

Hot rolling forming process

Perforation: Heat the round billet to 1250 ℃ and roll it diagonally to form a capillary tube with a wall thickness deviation of ≤± 5%;

Calibration: Three roll continuous rolling mill for precision forming, with an outer diameter tolerance of ± 0.5%.

Cold drawing finishing technology

Multi pass reduction: total reduction rate ≤ 40%, each pass ≤ 15% (to prevent microcracks);

Internal wall honing: Diamond grinding head polishing, roughness Ra ≤ 0.2 μ m (special for ultra-high pressure hydraulic pipe bridges).

Intelligent welding assistance

Intersection line cutting: Five axis CNC machine tool cuts truss nodes, with a groove angle error of ≤ 0.5 °;

Full penetration welding: Double wire submerged arc welding (SAW)+narrow gap TIG welding, UT inspection qualification rate ≥ 99.8%.

Long term protection system

Arc spraying aluminum: 200 μ m aluminum layer+80 μ m epoxy sealing paint, salt spray resistance ≥ 20000 hours;

Stainless steel composite pipe: base Q355qD+cladding 316L stainless steel (3mm), maintenance free throughout the entire life cycle.

Contact

Mobile number: 13848510731

Landline number: 0471-6490861

Address: Inside the courtyard of the Outer Transport Company, diagonally opposite the government of Haoqinying Town, Xincheng District, Hohhot City, Inner Mongolia (National Highway 110)