As the demand for stainless steel materials is more and more widely used, stainless steel welded pipes, as one of the applied varieties, are also widely used in various industries. As the stainless steel industry welded pipe, because of the different surface treatment, there are two kinds of welded pipe and polished pipe. Below are the principles and advantages and disadvantages of the two kinds of welded pipes.
The welded pipe with welding seam is welded by automatic welding, one side welding is formed on double side, and the weld on the pipe is smooth and smooth. Because the pickling pipe is made from the first grade stainless steel plate, the surface of the stainless steel welded pipe is consistent with the surface of the original plate. Polishing by hand welding pipe is formed by molding, polishing processing, surface passivation layer and cast weld pipe, stainless steel pipe surface showed a higher degree of brightness.
Below, look at the contrast between the stainless steel belt welded pipe and the polished pipe.
First, the wall thickness of the welded pipe with welding seam is more uniform and has higher bearing pressure. The wall thickness of the raw material will be thinner, especially in the weld area, by artificial polishing. The thinner the thickness of the weld wall, the smaller the bearing capacity of the weld.
Secondly, the welded pipe with weld seam pickling ensures the performance of austenitic stainless steel. Most stainless steel welded pipes are austenitic stainless steel used as raw materials, such as 201, 202, 304, 316L stainless steel and so on, while austenitic stainless steel is non-magnetic or weak magnetic. The chemical composition fluctuates after polishing, which makes the austenitic stainless steel magnetic.
The third is high corrosion resistance of welded pipe with seam pickling. The polishing pipe eliminates the passivation layer generated after pickling of raw materials, which results in the rusting of the welded pipe in normal environment, thus weakening the corrosion resistance of the stainless steel pipe.
In addition, the quality stability of the welded pipe with weld seam pickling is better. The polished welded pipe is a product popularized from the Wenzhou area. But because most of the Wenzhou area of stainless steel pipe used raw material is two grade materials or recycled material, to cover up the two grade stainless steel material surface spray, heavy leather and corrosion point must be polished; even some in order to reduce the cost of materials, full use of waste recycling in a pipe joint, a plurality of transverse seam. This kind of polished pipe is not guaranteed on the quality of the raw material, and the quality of the pipe itself is more difficult to ensure.
The last point is that the practicability of the welded pipe with weld seam pickling is better. In terms of industrial welded pipe, stainless steel welded pipe is mainly used for its own mechanical properties, corrosion resistance and channel performance. For stainless steel welded pipe, its surface gloss is relatively low, which, of course, besides decorative pipe and sanitary welded pipe. Therefore, the industrial welded pipe is not necessary to use the high cost but not the performance of the polished welded pipe.
Source: China Stainless Steel Welded Pipes Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)