Square rectangular high frequency welded steel pipe

Detailflow chartProcess videotechnical parameter

The company has 400×400mm and 250×250mm square and rectangular high-frequency welded steel pipe production lines each, which can produce 200,000 tons of square and rectangular high-frequency welded steel pipes every year. Products are widely used in various large-scale buildings and large-scale machinery and equipment and other fields.


Steel grade: Q235~Q355.


Executive standard: GB/T 6725-2017, GB/T 6728-2017 and other domestic and foreign standards of similar products and other higher standards.


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方矩形钢管生产工艺流程图


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Process video



Product main parameters (GB/T 6728-2017):


Wall thickness deviation:


When the wall thickness is t≤10.0mm:


Wall thickness deviation: ±0.1t.


When the wall thickness is t>10.0mm:


Wall thickness deviation: ±0.08t.


External arc radius:


When the wall thickness is t≤3.0mm:


Carbon steel (ReL≤320MPa): (1.0~2.5)t; low alloy steel (ReL>320MPa): (1.5~2.5)t.


When the wall thickness is 3.0<t≤6.0mm:


Carbon steel (ReL≤320MPa): (1.5~2.5)t; low alloy steel (ReL>320MPa): (2.0~3.0)t.


When the wall thickness is 6.0<t≤10.0mm:


Carbon steel (ReL≤320MPa): (2.0~3.0)t; low alloy steel (ReL>320MPa): (2.0~3.5)t.


When the wall thickness is t>10.0mm:


Carbon steel (ReL≤320MPa): (2.0~3.5)t; low alloy steel (ReL>320MPa): (2.5~4.0)t.


Plane convexity/concavity:


The convexity and concavity of the plane part of the section of section steel should not exceed 0.6% of the side length, but the minimum is 0.4mm.


Bending angle:


The deviation of the bending angle of section steel shall not be greater than ±1.5°.


Straightness deviation:


The curvature of section steel shall not be greater than 2mm per meter, and the total curvature shall not be greater than 0.15% of the total length.


Length deviation:


Length deviation: 3~20m.


If customers have higher requirements for quality, they can be negotiated.


Square steel pipe specification table


20×20×(1.2-2)mm

(Size deviation:±0.5mm)

90×90×(3-7)mm

(Size deviation:±0.75mm)

180×180×(4-10)mm

(Size deviation:±1.40mm)

30×30×(1.5-3)mm

(Size deviation:±0.5mm)

100×100×(4-8)mm

(Size deviation:±0.80mm)

200×200×(4-12)mm

(Size deviation:±1.60mm)

40×40×(1.5-4)mm

(Size deviation:±0.5mm)

120×120×(4-8)mm

(Size deviation:±0.90mm)

220×220×(4-14)mm

(Size deviation:±1.80mm)

50×50×(1.5-4.5)mm

(Size deviation:±0.5mm)

130×130×(4-10)mm

(Size deviation:±1.00mm)

250×250×(5-14)mm

(Size deviation:±2.00mm)

60×60×(2-5)mm

(Size deviation:±0.6mm)

135×135×(4-10)mm

(Size deviation:±1.00mm)

300×300×(6-14)mm

(Size deviation:±2.40mm)

70×70×(2.5-5)mm

(Size deviation:±0.65mm)

140×140×(4-10)mm

(Size deviation:±1.10mm)

350×350×(8-14)mm

(Size deviation:±2.80mm)

80×80×(2.5-6)mm

(Size deviation:±0.70mm)

150×150×(4-10)mm

(Size deviation:±1.20mm)

400×400×(8-14)mm

(Size deviation:±3.20mm)



Rectangular steel pipe specification table


30×20×(1.5-2.5)mm

(Size deviation:±0.50mm)

80×60×(3-5)mm

(Size deviation:±0.70mm)

200×150×(4-10)mm

(Size deviation:±1.50mm)

40×20×(1.5-3)mm

(Size deviation:±0.50mm)

90×50×(3-5)mm

(Size deviation:±0.75mm)

220×140×(4-12)mm

(Size deviation:±1.50mm)

40×25×(1.5-3)mm

(Size deviation:±0.50mm)

100×50×(3-5)mm

(Size deviation:±0.80mm)

250×150×(4-12)mm

(Size deviation:±1.60mm)

40×30×(1.5-3)mm

(Size deviation:±0.50mm)

120×60×(3-6)mm

(Size deviation:±0.90mm)

260×180×(5-14)mm

(Size deviation:±1.80mm)

50×25×(1.5-3)mm

(Size deviation:±0.50mm)

120×80×(3-6)mm

(Size deviation:±0.90mm)

300×200×(5-14)mm

(Size deviation:±2.00mm)

50×30×(1.5-4)mm

(Size deviation:±0.50mm)

140×80×(4-7)mm

(Size deviation:±1.00mm)

350×250×(6-14)mm

(Size deviation:±2.20mm)

60×30×(2-4)mm

(Size deviation:±0.60mm)

150×100×(4-8)mm

(Size deviation:±1.20mm)

400×200×(6-14)mm

(Size deviation:±2.40mm)

60×40×(2-4)mm

(Size deviation:±0.60mm)

160×80×(4-8)mm

(Size deviation:±1.20mm)

400×250×(6-14)mm

(Size deviation:±2.60mm)

70×50×(2-5)mm

(Size deviation:±0.60mm)

180×100×(4-10)mm

(Size deviation:±1.30mm)

450×250×(8-14)mm

(Size deviation:±2.80mm)

80×40×(2-5)mm

(Size deviation:±0.70mm)

200×120×(4-10)mm

(Size deviation:±1.40mm)

500×300×(8-14)mm

(Size deviation:±3.20mm)