The welding before the spiral steel pipe manufacturers basically used the welding rod to complete the welding, but following the development of our era, the electrode was gradually replaced by double-sided submerged arc welding. Why is Xiaobian saying this? In fact, our previous application of manual welding and double-sided submerged arc welding are protected by slag, but we have developed flux by hand-welded slag. Here we talk about the technology and rise of double-sided submerged arc welding.

Large diameter spiral tube production process

　　At present, the domestic seamless steel tube market price continues to be weak and stable. According to the data, the market price of seamless steel tube in key cities in China is the same, the average price of seamless steel tube is 4,319 yuan/ton (the same below), which is lower than yesterday's price. yuan/.

　　At present, the overall performance of the tunnel steel tube market is generally good, and the futures futures are mostly operated with shocks. The price of Tangshan area has risen by RMB 10/ton. In addition, due to the slow release of demand and the high price increase, the market has a relatively strong market. Watching the mood.

The steel pipe factory opened its first year after the year, and the market opened its door with a strong mentality. In addition, the “Golden Three” expectation drove the market price to rise sharply, and the increase was over 100 yuan.

In terms of the turnover of the steel pipe plant, the market opening futures continued to be weak, which aggravated the wait-and-see attitude of the overall spot demand.

The mainstream quotation of the steel pipe plant is running stably.

　　On March 3, 2019, during the National Conference, Wang Yilin, member of the National Committee of the Chinese People's Political Consultative Conference and chairman of the China National Petroleum Corporation, told the China Business News that the Sino-Russian natural gas pipeline will operate in advance.

　　On March 4, 2019, the Eurasian Economic Union issued Announcement No. 2019/159/SG12,

　　The government work report proposes to deepen the VAT reform, reduce the current 16% tax rate in industries such as manufacturing to 13%, and reduce the current 10% tax rate in the transportation, construction and other industries to 9%, ensuring significant tax burdens in major industries.

Spiral steel pipe is used for non-toxic 8710 anti-corrosion spiral steel pipe for drinking water , and is widely used in water quality pipeline.

The spiral tube is divided into three layers from the inside to the outside. The working steel pipe layer is generally made of seamless pipe ( gb8163-87 ) spiral welded pipe ( gb9711-88 ) according to the design and customer requirements. SY / t5038-92 ) and straight seam welded pipe ( gb3092-93 ). After the surface of the steel pipe is treated by advanced shot blasting, the corrosion grade of the steel pipe can reach the level of gb8923-1988 SA2 , and the surface roughness can reach the standard of gb6060.5-88 R = 12.5 microns.

The finished spiral steel pipe is discharged after water cooling, but after all, after high temperature heating, the temperature of the spiral steel pipe is still quite high after water cooling, so the following points should be noted after the spiral pipe is taken off the summer :

When stacking galvanized steel pipes, we must do a reasonable stacking and advanced first-hand

Difference between cold galvanizing and hot galvanizing

In recent years, many applications of hot rolled coils, especially thin gauge products, in the automotive industry, construction occupation, compressor occupation, etc.

The raw material of cold-formed steel is hot-rolled coil, and most of the coils used for cold-formed steel have no thickened plates at all.

Hot rolled coil products have excellent functions such as high strength, good resistance, easy processing and excellent weldability. They are widely used in cold rolled substrates, ships, cars, bridges, construction, machinery, oil pipelines, pressure vessels. Waiting for a production career.

The market volume of large-diameter seamless steel pipe has decreased compared with the previous period, and the turnover of rolled billet enterprises has also been stopped. The demand for billet market is not large, so the price is difficult to continue to rise.

The output of crude steel increased slightly for two consecutive months. The contradiction between supply and demand of thick-walled seamless steel pipe market was prominent, and the price of steel fell. Steel prices rebounded slightly in October, but due to the overall supply and demand situation, steel prices will show a small dynamic trend in the later period.

The market for thick-walled seamless steel pipes is difficult to change, prices in many regions are generally lowered, and the willingness of downstream steel mills to purchase is still low. The main body of the domestically produced mineral market was stable this week, and the stalemate between supply and demand was highlighted.