Stainless steel polished pipe has good corrosion resistance, heat resistance, low temperature strength and mechanical properties, and good hot workability such as stamping and bending. It is widely used in seawater equipment, chemical, dye, paper, oxalic acid, fertilizer and other production equipment. However, the problem is how to deal with the black surface of the stainless steel polished pipe.

Generally speaking, this is not the case with good stainless steel polished pipe products. If the surface of the tube is blackened during long-term use, it is because the stainless steel polished tube produces an oxide film under the action of air. The role of the oxide film protects the metal inside the stainless steel from being oxidized. This oxide film does not need to be specially Wipe off, there is no damage to the tube. Because the stainless steel polished tube of different materials has some differences in the element content, the color of the oxidized film will also be different, but it has no effect on the tube. If you think this is not very beautiful, you can do polishing.

If the stainless steel polished pipe is welded, its surface is black, which is caused by insufficient welding gas purity or high temperature oxidation. The following three methods teach you how to avoid such things from happening.

1.Increase the purity of the argon gas used in the welding of stainless steel processing and polishing tubes to pure argon. From the outer surface of the tube, the brightness of pure argon is significantly brighter than that of ordinary argon welding.

2. Argon gas on the back should be well protected. Important stainless steel polished tubes should be protected on the back after welding. Otherwise, high temperature oxidation will cause oxidation of the welding layer passing through the back to produce defects. After protection, it can effectively prevent the backside oxidation.

3. You can apply a back protective agent on the back, which is a kind of protection that can save argon gas. It can be applied with a thickness of about 1 mm. Then, when the front is welded, a thin film is formed on the back to form a protective layer.