Views: 1 Author: Site Editor Publish Time: 2020-10-30 Origin: Site
Seamless steel pipe is an important new field in modern steel pipe production, and it is one of the main development directions of the steel pipe industry today. Depending on the different degrees of the different processes used to eliminate the effect of welded pipe welds, this new type of steel pipe can be widely used to replace seamless steel pipes in various corresponding fields. The seamless deep processing of butt welded pipes is a new, low-consumption and new method of modern steel pipe production.
Seamless steel pipes are produced through the seamless process of welded steel pipes. There are four types of seamless processes for welded pipes: One is the overall heating and normalizing annealing treatment of the welded pipe, followed by tension reducing rolling; the other is the welded pipe is pickled, lubricated and then cold drawn and annealed; the third is the entire welded pipe. Heating normalized annealing treatment; Fourth, on-line local induction heating treatment of the weld seam of the welded pipe.
Due to the advancement of modern technology, more and more people pay attention to seamless steel pipes. Now let me introduce the production method of seamless steel pipes.
1. Generally, the service temperature of seamless steel pipes is below 450℃. Domestic pipes are mainly made of No. 10 and No. 20 carbon steel hot-rolled pipes or cold-drawn pipes.
2. The high-pressure square tube is often in high temperature and high pressure conditions when used. The tube will be oxidized and corroded under the action of high temperature flue gas and water vapor. The steel pipe is required to have high strength, high oxidation and corrosion resistance, and good structure stability.
Seamless steel pipe is also called hot-rolled seamless steel pipe or hot-rolled steel pipe. The production process of seamless steel pipes The importance of seamless steel pipes is that the expansion reduction process completed by expansion reduction is a continuous rolling process of hollow base material without mandrel. Under the condition of ensuring the welding quality of the main pipe, the welding pipe expansion reduction process is to heat the welded pipe as a whole to above 950 degrees Celsius, and then roll it through the expansion reducing machine (the expansion reducing machine has 24 passes). For finished pipes with diameters and wall thicknesses, the thermally expanded seamless steel pipes produced by this process are substantially different from ordinary high-frequency welded pipes. After heating by a heating furnace, the metallographic structure and mechanical properties of the weld and the parent body can reach completeness. In addition, the dimensional accuracy of the steel pipe, especially the roundness and wall thickness accuracy of the pipe body, is better than that of similar seamless pipes through the multi-pass tension reducing mill rolling and active control. In the fluid pipes produced by developed countries in the world, a large number of boiler pipes have adopted the seamless process of welded pipes. With the development of society, the situation of domestic hot-rolled welded pipes gradually replacing seamless pipes has taken shape.