Q235 spiral tube belongs to carbon structural steel, mainly made of molten iron and scrap steel. The sulfur and phosphorus content in the steel is higher than that of high-quality carbon structural steel, generally with sulfur ≤ 0.050% and phosphorus ≤ 0.045%. The content of other alloying elements introduced into steel from raw materials, such as chromium, nickel, and copper, generally does not exceed 0.30%. According to the composition and performance requirements, the grades of such steel are represented by Q195, Q215A, B, Q235A, B, C, D, Q255A, B, Q275, and other steel grades.

Note: "Q" is the capital Chinese pinyin prefix of the "qu" character for yielding, followed by the minimum yield point (σ s) value of the grade. The symbols after it are divided into four categories according to the content of impurity elements (sulfur, phosphorus) in the steel, from high to low, accompanied by changes in carbon and manganese elements: A, B, C, D.

Q235Spiral welded pipe specifications

Spiral tube

Spiral seam submerged arc welded steel pipes (SY5036-83) for pressurized fluid transportation are mainly used for pipelines transporting oil and natural gas; Spiral seam high-frequency welded steel pipe for pressurized fluid transportation (SY5038-83), welded by high-frequency lap welding method, used for spiral seam high-frequency welded steel pipe for pressurized fluid transportation. Steel pipes have strong pressure bearing capacity, good plasticity, and are easy to weld and process into shapes; Spiral seam submerged arc welded steel pipes (SY5037-83) for general low-pressure fluid transportation are made using double-sided automatic submerged arc welding or single-sided welding methods, and are used for submerged arc welded steel pipes for general low-pressure fluid transportation such as water, gas, air, and steam.

Classification of Spiral Tube Standards

The commonly used standards for spiral steel pipes are generally divided into

(1) SY/T5037-2000 (Standard, also known as Spiral Seam Submerged Arc Welded Steel Pipe for Ordinary Fluid Transport Pipeline)

(2) GB/T9711.1-1997 (National Standard, also known as Petroleum and Natural Gas Industry Steel Pipe Delivery Technical Conditions Part 1: A-grade Steel Pipe (currently, GB/T9711.2 B-grade Steel Pipe has strict requirements))

(3) API-5L (American Petroleum Institute, also known as pipeline steel pipe); It is divided into two levels: PSL1 and PSL2, and SY/T5040-92 (spiral seam submerged arc welded steel pipes for piles)