10*10-2000*2000mm ASTM A572 Square Hollow Section Rectangular Steel Pipe

Product Induction

ASTM A572 steel grades include Gr.42/50/55/60/65, with yield strength ≥ 345 MPa and tensile strength ≥ 450 MPa, representing a high-strength low-alloy structural steel. ASTM A572 square and rectangular tubes feature maximum dimensions of 1200 mm edge length and 50 mm wall thickness, with a maximum weight per piece ≤ 1,500 kg. Characterized by high strength and toughness, it can be processed in a single operation based on outer diameter, wall thickness, length, bevel, internal partitions, and openings. Surface treatments include black pipe, oil coating, spray painting, hot-dip galvanizing (200–600 g/m²), , pre-galvanized (40–80 g/m²), or 3PE coating. Applications include high-rise building columns, offshore drilling platforms, bridge towers, wind turbine towers and door frames, port machinery, mining conveyor bridges, photovoltaic racks, heavy-duty truck frames, and railway vehicle underframes.

Product Pictures

Specification

ASTM A572 Chemical Composition

ASTM A572 Mechanical Properties

ASTM A572 Material Performance Advantages

1. Gr50 strength exceeds Q235 by 38%, enabling 15–20% wall thickness reduction under equivalent loads and 8–12% steel savings.

2. CEV ≤0.44; no preheating required for thickness ≤25 mm. Weld hardness ≤220 HV eliminates cold cracking risk with excellent weldability.

3. Akv ≥34 J at 0°C, with measured values of 45–150 J at -20°C, delivering high toughness suitable for sub-zero and dynamic-loaded structures.

4. Fatigue limit ≈280 MPa (R=0.1), 40% higher than Q235, ideal for cyclically loaded components like bridges and crane girders.

5. Extensive dimensional coverage: maximum side length 1200 mm, wall thickness 50 mm, unit weight ≤1.5 t/m. Meets requirements for “single-piece-through” applications in large-span truss chords, high-rise columns, and offshore pile legs.

Square and Rectangular Tube Production Process

Welded Square and Rectangular Tubes:

1. Uncoiling - Leveling

2. Cold Bending

3. High-Frequency Welding: Induction coil heating at 100–400 kHz raises butt edges to 1300–1400°C. Pressure from squeeze rollers completes fusion at 20–50 m min⁻¹ welding speed. Internal/external burrs are immediately planed off, yielding a 2–4 mm weld width.

4. In-line weld inspection

5. Sizing - Straightening

6. Cut-to-length - Beveled saw edges

7. Optional Post-Processing:

Hot-dip galvanizing: Immersion in 450°C molten zinc for 1–3 min, zinc coating 45–600 g/m²;

End face milling, bolt hole punching, marking/code spraying;

Sandblasting rust removal to SA2.5 + epoxy zinc-rich primer 60 µm.

Seamless Square and Rectangular Tubes:

1. Seamless square and rectangular tubes (round-to-square conversion for thick-walled high-pressure applications)

2. Billet heating → Piercing → Continuous rolling mill → Sizing round tubes; Multi-pass rolling die “round → oval → square/rectangular”, with ≤12% reduction per pass and progressively decreasing corner radii (R);

3. Heat treatment (normalizing or quenching and tempering) → Straightening → Non-destructive testing → Cutting to length.

Other Pipe Products

We also offer stainless steel pipes, welded pipes, seamless pipes, spiral pipes, galvanized pipes, special-shaped pipes, thick-walled pipes, and more. Customization is available, and cut to length.

FAQ

Q: What are the advantages of square and rectangular tubes compared to round tubes?

A: They offer a 30–50% increase in sectional moment of inertia, providing superior bending and torsional strength for the same weight. With four straight sides, they require less welding at joints, feature a clean appearance, and are suitable for exposed structures.

Q: Can A572 square and rectangular tubes directly replace A36?

A: Strength increases by 38% (Grade 50 yield strength 345 MPa vs. A36 250 MPa), allowing wall thickness reduction by 15–20%; however, the price is slightly higher, and connection plate thickness and weld toe dimensions require verification.

Q: Is preheating required for welding?

A: For Gr50 with wall thickness ≤25 mm and ambient temperature ≥0°C, preheating is not required. For Gr60/65 with wall thickness >20 mm, preheating at 100–150°C is recommended, followed by stress relief at 550°C after welding.

Q: Can hot-dip galvanizing be performed?

A: Yes. Zinc coating thickness: 45–600 g/m² (both sides). However, note that yield strength decreases by approximately 5% after galvanizing.

Q: What are the available custom lengths?

A: Standard lengths are 5.8 m / 6 m / 12 m; custom lengths from 4 to 18 m are available with a tolerance of +50 mm.

Q: How can I get your quotation as soon as possible?

A:Please contact:

Email:[email protected]

Wechat/whatsapp/mobile: + 86 13512028034