The forms and differences of stainless steel pipes

At present, the market competition of stainless steel seamless steel pipes is relatively fierce. However, due to the high production process requirements of seamless steel pipes, the manufacturing cost of seamless steel pipes is always more expensive, resulting in the economic benefits of seamless steel pipes being reduced.
However, with the rapid development of domestic iron and steel metallurgical technology, new products that can replace seamless steel pipes have also been used, mainly including straight seam welded pipes and thermal tension reducer pipes. So have their performance reached the various indicators of seamless steel pipes? ? Let’s introduce it in detail below.
The quality of the welds on stainless steel welded pipes directly determines the quality of the welded pipes, which is also the biggest difference between welded pipes and seamless steel pipes. After high-frequency welding of straight seam welded pipes, the carbon collected in the straight seam cannot be completely eliminated. The weld seam and the parent body are only connected together, and are not completely melted into one. This makes it impossible to withstand long-term high-pressure operations.
After high-frequency welding, the thermal tension reduction stainless steel pipe must undergo overall heating at 800°C, overall annealing, and then open transformation treatment. After this series of processing techniques, the structural properties of the weld and the parent body have been completely identical and Melted into one, this completes the process from seamed to seamless.
Differences in technology lead to differences in the quality of stainless steel pipe products. After high-frequency welding, thermal tension reduction steel pipes need to undergo a process that is not performed on straight seam welded pipes, which is to remove the internal and external burrs of the pipe online. Because the burrs on the pipe wall will affect the flow of fluid in the pipe, they will also hinder the normal flow of the fluid, thus creating vortices. According to the principle of fluid mechanics, the local pressure on the weld seam will inevitably increase, and the uneven force will greatly reduce the insurance coefficient of the welded pipe. In the production process of thermal tension reduction steel pipe, the danger of burrs is fully considered, and burrs are removed to limit the number. This results in a uniform wall thickness and no difference in appearance from seamless pipes. So from this point of view, the thermal tension reduction steel pipe has also completed the transition from seamed to seamless.
Of course, the difference between the two is not limited to the above three points, but it is enough to show that there are still big differences between straight seam welded pipes and thermal tension reduced steel pipes. On the basis of the straight seam welded pipe, the latter has also carried out a series of new technological treatments such as online internal and external burr removal, overall heating and deformation, which has made it a qualitative leap and can be widely used in the medium and high pressure fields. Seam welded pipes are generally only suitable for water and gas transportation in low pressure environments.