Q235B LSAW Steel Pipe DN650

What is the core definition of Q235B LSAW steel pipe?

From the perspective of name disassembly, "Q235B" is the material identification of pipes, where "Q" stands for yield strength, "235" stands for yield strength of this material ≥235MPa, and "B" stands for impact test temperature of 20℃ and impact work ≥27J, which belongs to the general grade of carbon structural steel and is one of the most widely used basic steels in industrial and infrastructure fields at present. According to GB/T 700-2024 national standard, Q235B carbon structural steel has carbon content ≤0.20%, silicon content ≤0.35%, manganese content ≤ 0.35~0.80%, phosphorus and sulfur content ≤0.045%, balanced chemical composition, plasticity, toughness and weldability, and can be adapted to various welding processes without complicated processing pretreatment.

"LSAW", that is, longitudinal submerged arc welding, is one of the core technologies of steel pipe welding, and it is also called the three mainstream steel pipe welding technologies together with high frequency longitudinal welding (ERW) and spiral submerged arc welding (SSAW). Its core principle is that after the steel plate is precisely formed, it is welded along the longitudinal direction of the steel plate by submerged arc welding technology, and the weld is parallel to the axis of the steel pipe. During the welding process, the arc burns under the flux layer, effectively isolating impurities such as air and moisture, ensuring uniform weld quality and sufficient penetration, and the weld strength can approach or reach the parent metal strength. Compared with other welding processes, LSAW process is more suitable for the production of medium-thick wall and large-diameter steel pipes. It can produce steel pipes with diameters ranging from DN 300 to DN 2000 (corresponding to external diameter of 325mm~2020mm), wall thickness of 6-80mm and length of 6-12m, and has high production efficiency and strong batch stability, which can meet the core requirements of large-scale projects for uniform pipe specifications and stable quality.

On the whole, Q235B LSAW steel pipe is not a single specification product, but a series of pipes with various diameters and wall thicknesses, among which the commonly used diameters range from DN300 to DN600, which meets the transportation needs of small and medium-sized projects. Each specification strictly follows the national standards such as GB/T 9711 (oil and gas industry transportation steel pipe) and GB/T 700-2024 (carbon structural steel) to ensure that. Compared with seamless steel pipe, spiral welded pipe, stainless steel pipe and other pipes, Q235B LSAW steel pipe's core positioning is "balance between economy and practicality", which can not only meet the transportation demand of medium and low pressure working conditions, but also greatly reduce the project procurement and construction cost, which is the core logic for Q235b LSAW steel pipe to become "just-needed pipe" in the industrial and infrastructure fields.