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First post, some basic stuff – everyone take a look. I hope it’s useful. Several surface treatment methods for pipes: To improve the surface quality of stainless steel pipe systems, that is, to enhance the surface morphology and structure, reduce energy levels, and decrease the number of interlayers, the common surface treatment methods currently in use are as follows: 1. Mechanical drawing (Plug draw), abbreviated as PD. Improving surface roughness through precise cold drawing of plugs can enhance the surface structure, but it does not improve the morphological structure, energy level, or the number of interlayers. As the most basic surface treatment process, the roughness achieved through mechanical drawing lays the foundation for other surface treatment methods. 2. Mechanically Polished is referred to as MP. Improving surface roughness through precision grinding can enhance the surface texture, but it does not improve the morphological structure, energy level, or the number of interlayers. 3. Buffed Polished, abbreviated as BP. A common method used in the decorative stainless steel industry to improve surface brightness; although the Ra value may be good, many cracks can be observed under an electron microscope, the actual surface area increases, and there are locally separated ferrite and martensite structures. The surface is contaminated with many impurities, such as grinding particles. Due to the use of polishing paste, much energy is stored in the previously formed depressions, which also increases the amount of medium. Such pipes are generally not allowed to be used in sensitive and corrosive media in microelectronics, optoelectronics, and biopharmaceuticals. 4. Pickling or passivation (Pickled & Passivated/Chemically Polished), abbreviated as AP and CP. Cleaning the pipeline with acid or passivation does not increase surface roughness, but it can remove residual particles from the surface and reduce the energy level; however, it does not decrease the number of interlayers. 5. Bright Annealing, abbreviated as BA. High-temperature heat treatment under hydrogenation or vacuum conditions eliminates internal stresses on the one hand, and forms a passivation layer on the surface of the pipe on the other hand, thereby improving the morphological structure and reducing the energy level, without increasing the surface roughness. 6. Anodic electrochemical polishing, abbreviated as AC. European factories apply an additional surface treatment process on top of BA, namely a mild electropolishing process, in order to minimize the surface area as much as possible, thicken the passivation film, thereby enhancing corrosion resistance, improving the surface morphology, and reducing energy consumption. Although the products treated in this way do not have the same shine as before, their surface quality has improved significantly; no particles are formed, and the amount of iron and iron oxide in the surface layer is reduced. 7. Electro-polishing, abbreviated as EP. Through electrochemical polishing, the surface morphology and structure can be greatly improved, thereby minimizing the actual surface area to the greatest extent possible. The surface is covered by a thick, sealed layer of chromium oxide; the energy level is close to that of the alloy under normal conditions, and the amount of dielectric material is reduced to a minimum. Industries such as microelectronics, optoelectronics, and biopharmaceuticals, which require high-purity and clean pipeline systems for transporting sensitive or corrosive media, generally use products for bright annealing (BA), subelectrochemical polishing (AC), and electrochemical polishing (EP).