Characteristics of Q235B straight seam steel pipe
1. Production method of Q235B straight seam steel pipe: SAW double-sided submerged arc welding steel pipe, ERW high-frequency resistance welding steel pipe
2. Product implementation standards of Q235B straight seam steel pipe: GB/T3091 welded steel pipe for low-pressure fluid transportation, GB/T13793 straight seam electric welded steel pipe.
3. Product specifications of Q235B straight seam steel pipe: outer diameter 10mm~2060mm, wall thickness: 1mm~100mm.
4. Chemical composition of Q235B straight seam steel pipe: Carbon: 0.12~0.20% Manganese: 0.30~0.670 Silicon: ≤0.30 Sulfur: ≤0.045 Phosphorus: ≤0.045
5. Tensile strength of Q235B straight seam steel pipe: 375MPa~500MPa
Usually the length of electric resistance welding (ERW) steel pipe is 4000㎡m~12000mm. The usual length of submerged arc welding (SAW) steel pipe is 3000 mm~12000㎡m. The fixed length of the cut-to-length steel pipe should be within the usual length range, and its allowable deviation is “2mm. The multiple length of the steel pipe should be within the usual length range, and its allowable deviation is *”mm. Each multiple length should leave a 5mm~10mm cut margin.
Curvature The steel pipe with a nominal outer diameter not greater than 168.3㎡m should be straight for use, or the curvature index should be stipulated by agreement between the supply and demand parties. For steel pipes with a nominal outer diameter greater than 168.3mm, the curvature should not be greater than 0.2% of the total length of the steel pipe. The two end faces of the steel pipe at the pipe end should be perpendicular to the axis of the steel pipe, and there should be no cut burrs. For steel pipes with an outer diameter greater than 168.3m, the incision slope should not exceed 5㎡. According to the requirements of the demander, after the agreement between the supply and demand parties and indicated in the contract, the end of the steel pipe with a wall thickness greater than 4″ can be processed with a bevel angle of 30° and the remaining thickness of the pipe end is 1.6. Bending test Resistance welded steel pipes with a nominal outer diameter of not more than 60.8 should be subjected to bending tests. No fillers are required during the bending test. The bending radius of ungalvanized steel pipes is 6 times the nominal outer diameter, and the bending radius of galvanized steel pipes is 8 times the nominal outer diameter. The bending angle is 90°, and the weld is located on the side of the bending direction. No cracks should appear on the specimen after the test. There should be no zinc peeling on the galvanized steel pipe.
Flattening test Resistance welded steel pipes with a nominal outer diameter of not more than 0.3㎡m should be subjected to flattening tests. For resistance welded steel pipes with a nominal outer diameter of not more than 168.3, when the distance between the two flattening plates is 3/4 of the nominal outer diameter of the steel pipe When the distance between the two pressure plates is 3/5 of the nominal outer diameter, no cracks should appear in other parts except the weld; for resistance welded steel pipes with a nominal outer diameter greater than 168.3m, when the distance between the two pressure plates is 2/3 of the nominal outer diameter of the steel pipe, no cracks should appear in the weld; when the distance between the two pressure plates is 1/3 of the nominal outer diameter of the steel pipe, no cracks should appear in other parts except the weld. Hydraulic test steel pipes should be hydraulically tested one by one, and the test pressure should comply with the provisions of Table 6. The pressure stabilization time of steel pipes with a nominal outer diameter of less than 508㎡ should be no less than 5s; the pressure stabilization time of steel pipes with a nominal outer diameter of not less than 508㎡m should be no less than 10s. Under the test pressure, the steel pipe should not leak. The manufacturer can also use eddy current testing or ultrasonic testing instead of hydraulic testing. Eddy’s current testing of steel pipes is carried out in accordance with the relevant provisions, and the artificial defects (drilling holes) of the comparison sample are Class A: Ultrasonic testing GB/T 11345 The inspection level is A and the assessment level is level 3. The hydraulic test shall prevail during arbitration.
Post time: May-07-2025