Specification

9711.2 gb 9711.1 spiral steel pipe, spiral steel pipe or spiral steel pipe, material classification: 16 mn material spiral steel pipe, Q345B spiral steel pipe, L245 spiral steel pipe, L360 spiral steel pipe, X40 - X80 spiral steel pipe, main USES, sewage treatment with spiral steel pipe, water purification with spiral steel pipe, water plant with spiral steel pipe, plant chemical enterprise with spiral steel tube pole, nuclear power with the spiral steel pipe, flammable liquid with spiral steel pipe, non combustible liquid with spiral steel pipe, gb spiral steel pipe, oil, or SY/T5037 spiral steel pipe. The product is made of hot rolled steel strip, often made by spiral forming and automatic submerged arc welding

The trend of the spiral steel pipe market demand both rapid and random growth will not change fundamentally. Whether the spiral steel pipe market can maintain the rapid development of the hub depends on the change of demand. Macro economy is regulated by the policy level, which will slow down the market growth rate in the future

The main raw material is iron water plus scrap steel. The content of sulphur and phosphorus in steel is higher than that of high-quality carbon structural steel. Generally, sulphur is less than 0.050% and phosphorus is less than 0.045%. The content of other alloy elements brought into the steel by raw materials, such as chromium, nickel and copper is generally no more than 0.30%. According to the composition and performance requirements, the grades of such steel are indicated by the steel grades Q195, Q215A, B, Q235A, B, C, D, Q255A, B and Q275.

Note: "Q" is the upper capital character of the Chinese phonetic alphabet of the yield of "qu", and the subsequent number is the value of the minimum yield point (xun s) of the brand, and the subsequent symbol is divided into A, B, C and D according to the content of the steel impurity elements (sulphur and phosphorus) from high to low and accompanied by the changes of carbon and manganese elements.

In gb700-88 standard, carbon structural steel Q235 is divided into four grades of A, B, C and D according to the metallurgical quality. Each grade of steel contains 0.3 percent of Si content. The difference lies in the difference of carbon content, sulfur content and phosphorus content. The carbon content of AB grade is 0.14%~0.22% and 0.12%~0.20%, the carbon content of CD grade is 0.18% and 0.17% at the same time, the Mn content of A grade is the smallest, and the content of d-grade SP is the smallest.