At present, industrial stainless steel welded pipe is widely used in the application market of stainless steel at home and abroad. Among them, because of the difference of surface processing technology, the stainless steel industrial welded pipe is mainly divided into two kinds of welded pipe and polished welded pipe. The following are the principles and advantages and disadvantages of them.
Stainless steel welded pipe with welded seam pickling is made by automatic welding. The process is single side welding to form two sides, and the weld is uniform and smooth. Because the acid pickling stainless steel welded pipe is made from the first grade stainless steel sheet, and the surface of the welded pipe is the same as the surface of the original plate. It is after polishing pipe molding using manual welding, then polished cast weld and surface passivation layer, so the surface brightness high stainless steel tube.
Below is a comparison of the advantages and disadvantages of the stainless steel belt welded pipe and the polished welded pipe.
First, the wall thickness of stainless steel welded pipe with weld acid pickling is more uniform and the pressure bearing performance is stronger. The wall thickness of the original pipe will be thinner, especially in the weld area, when the polishing pipe is artificially polished. The thinner the wall thickness of the weld zone, the lower its bearing capacity.
Secondly, stainless steel welded pipe with welded seam pickling can ensure the integrity of austenitic stainless steel. Most stainless steel welded pipes are made of austenitic stainless steel as raw materials, such as 201, 202, 304 and 316 stainless steel, because the austenitic microstructure is not magnetic or weak magnetic. After polishing, the polishing pipe will result in small change in chemical composition, which makes the austenitic stainless steel have more obvious magnetism.
The corrosion resistance of stainless steel welded pipe with weld acid pickling is stronger. The polishing stainless steel welded pipe eliminates the original passivation layer after pickling, so that the polishing pipe is also easy to rust in normal environment, and the corrosion resistance will weaken.
The quality stability of stainless steel welded pipe with weld acid pickling is higher. The polishing welded pipe is because the raw materials are used in grade two or even recycled materials, and to cover up the defects of these materials on the surface of the polishing; even to reduce the cost of materials, but also the use of waste plates, so can not guarantee the quality stability of polishing welded pipe, the problem is very easy.
Stainless steel welded pipe with welded seam pickling is more practical. Because of the mechanical properties, industrial pipe mainly used stainless steel pipe its corrosion resistance, but to the requirements of the surface of the pipe light degree is not very high, of course there must exclude decorative pipes and sanitary pipe, so many industrial pipe is not necessary to use polishing of stainless steel welded pipe of high cost and unstable performance.
Source: China Stainless Steel Pipes Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)