What are the advantages of pickling stainless steel welded pipes with welds?

As the application requirements of stainless steel materials become wider and deeper, stainless steel welded pipes, one of the application varieties, are also widely used in various industries. As stainless steel industrial welded pipes, there are mainly two types: pickled welded pipes with welds and polished welded pipes due to different surface treatments. The following mainly talks about the principles, advantages and disadvantages of these two types of welded pipes.
The pickled welded pipe with welded seams is welded by automatic welding, and is welded on one side and formed on both sides. The welds on the pipe are uniform, smooth and flat. Because the pickled welded pipes are made of first-grade stainless steel plates, the surface of the stainless steel welded pipes remains consistent with the surface of the original flat plates. The polished welded pipe is formed by manual welding and then polished. The welded pipe weld and the surface passivation layer of the pipe are discarded. The surface of the stainless steel welded pipe shows a higher degree of brightness.
Let’s take a look at the comparison between pickled stainless steel welded pipes and polished welded pipes.
First, the wall thickness of pickled welded pipes with welds is relatively uniform and has a relatively high bearing pressure. The manual polishing process of polished welded pipe will cause the wall thickness of the raw material to become thinner, especially in the weld area. The thinner the wall thickness of the weld, the smaller its pressure-bearing capacity.
Secondly, the pickled welded pipe with weld seam ensures the performance of austenitic stainless steel. Most stainless steel welded pipes use austenitic stainless steel as raw material, such as 201, 202, 304, 316L stainless steel, etc., and austenitic stainless steel is non-magnetic or weakly magnetic. The chemical composition of polished welded pipes fluctuates after polishing, making austenitic stainless steel magnetic.
The third is that pickled welded pipes with welds have high corrosion resistance. Polished welded pipes remove the passivation layer generated after pickling of raw materials, which makes polished welded pipes very easy to rust in normal environments, thereby weakening the corrosion resistance of stainless steel pipes.
In addition, the quality stability of pickled welded pipes with welds is better. Polished welded pipe is a product promoted from Wenzhou area. Because most of the raw materials used in stainless steel welded pipes in Wenzhou are secondary materials or recycled materials, polishing is necessary to cover up splashes, heavy skin, and corrosion spots on the surface of secondary stainless steel materials; some even in order to further reduce material costs , all used waste plates are reused, and multiple vertical and horizontal welds are spliced on one welded pipe. The quality of raw materials for this type of polished welded pipe cannot be guaranteed, and the quality of the welded pipe itself cannot be guaranteed.
The latter point is that pickled welded pipes with welds are more practical. In terms of industrial welded pipes, the mechanical properties, corrosion resistance and channel performance of stainless steel welded pipes are mainly used. The surface glossiness of stainless steel welded pipes is relatively low, except for decorative welded pipes and sanitary welded pipes. Therefore, there is no need for industrial welded pipes to use polished welded pipes that are costly but have no guaranteed performance.