AP Stainless Steel Pipe: (Acid Pickling) Stainless steel pipes that have undergone acid pickling treatment. The corrosion resistance of stainless steel mainly comes from the reaction of chromium with oxygen, forming a dense protective layer on its surface. Acid pickling allows this reaction to occur earlier, improving the corrosion resistance of the stainless steel pipe. The pickling process removes oil and other substances adhering to the pipe surface during production. The inner and outer surfaces of the pipe are relatively rough and prone to the adhesion of suspended impurities.

MP Stainless Steel Pipe: (Mechanical Polishing) Stainless steel pipes that have undergone mechanical polishing. Polishing wheels or belts use abrasive particles in the polishing compound to polish the surface of the stainless steel pipe, achieving a smooth, polished effect. The brightness and effect depend on the type of processing method. While mechanical polishing is more aesthetically pleasing, it also reduces corrosion resistance. Therefore, when used in corrosive environments, passivation treatment is required, and polishing material residue often remains on the surface of the stainless steel pipe.

BA Stainless Steel Pipe: (Bright Annealing) Bright annealed stainless steel pipe. During the manufacturing process of stainless steel pipe, the grease grains used for lubrication may deform due to processing. To prevent grease residue in the stainless steel pipe, argon gas is used as the furnace atmosphere during annealing at high temperatures. The argon gas combines with the carbon and oxygen on the surface of the stainless steel pipe and burns, further cleaning the surface and producing a good effect. This method of using pure argon gas for annealing, followed by rapid cooling to brighten the surface, is called bright annealing. While this method ensures the stainless steel pipe is completely clean and free of any external contaminants, the brightness of this surface, compared to other polishing methods such as mechanical, chemical, and electrolytic polishing, may appear somewhat matte. Of course, the effect is also related to the argon gas content and the number of heating cycles.

EP Stainless Steel Pipe: (Electro Polishing) Electropolishing of Stainless Steel Pipes. Electropolishing utilizes anodizing, employing electrochemical principles to appropriately adjust voltage, current, acid composition, and polishing time. This not only achieves a bright, smooth, and clean surface for stainless steel pipes but also enhances their corrosion resistance, making it the optimal method for surface brightening. However, this process also significantly increases cost and technical complexity.

However, because electropolishing reveals the original state of the stainless steel pipe surface, severe scratches, pores, inclusions, or precipitates can all lead to electropolishing failure. Unlike chemical polishing, which is also performed in an acidic environment, electropolishing prevents intergranular corrosion. Furthermore, the corrosion resistance of the stainless steel pipe can be improved by controlling the thickness of the chromium oxide film layer.