In addition to brand, material origin, and production and processing technology, a key factor that directly affects the price of stainless steel pipes is the surface treatment method. In order to further improve the characteristics of stainless steel pipes, there are several specific methods for processing the inner and outer surfaces of the pipes: pickling passivation (AP), mechanical polishing (MP), bright annealing (BA), and electrolytic polishing (EP) treatment processes.
According to the test data and actual results, the roughness of the 316L stainless steel pipe is reduced, and the surface adsorption is weakened. In this case, what is the difference between AP grade, MP grade, BA grade, and EP grade stainless steel pipe? See below what's brought to you by Huiyingsteel, a professional stainless steel tube manufacturer.
AP grade stainless steel pipe: AP (Acid Pickling) pickling treatment
The corrosion resistance of stainless steel mainly comes from the formation of a dense oxide film on its surface after the chemical reaction between the chromium element contained in it and the oxygen. The role of the pickling process is to allow this reaction to occur in advance to improve the corrosion resistance of the stainless steel tube. During the pickling process, the oily dirt attached to the surface of the stainless steel pipe and some substances contaminated in the production will be completely removed. The inner and outer surfaces of the pipeline are relatively rough, and it is easy to adhere to the suspended solids and impurities.
BA grade stainless steel pipe: BA (Bright Annealing) bright annealing
The polishing wheel or polishing belt uses the abrasive in the polishing agent to grind and polish the surface of the 316L stainless steel pipe, so as to promote the surface of the 316L stainless steel pipe to achieve a smooth and smooth polishing effect. Its brightness depends on the type of processing technology. In addition, although it is more beautiful after mechanical polishing, it will also reduce the corrosion resistance, so when it is used in a corrosive environment, it needs to be passivated, and the surface of the 316L stainless steel pipe often has polishing material residues.
MP grade stainless steel pipe: MP (Mechanical polishing) mechanical polishing
During the production process of the 316L stainless steel tube, the grease grains used for lubrication may be deformed due to production and processing. In order to avoid the grease remaining in the 316L stainless steel tube, the high temperature is reasonably used in the annealing process and argon is used as the atmosphere in the furnace. By combining argon gas with carbon and oxygen on the surface of the 316L stainless steel tube, the surface of the 316L stainless steel tube is further cleaned to form a bright surface effect. This kind of annealing heating and rapid cooling using pure argon gas is called bright in the way of brightening the glossy surface. annealing.
Although brightening the surface in this way can keep the 316L stainless steel tube clean without any foreign pollution. However, if the brightness on this surface is compared with other polishing methods such as mechanical, chemical, and electrolytic, there will be a foggy feeling. Of course, its effect is also related to the content of argon and the number of times of heat.
EP grade stainless steel pipe: EP (Electro Polishing) electrolytic polishing
Electrolytic polishing is a method of anodic treatment. According to the principle of electrochemistry, properly adjusting the voltage, current, acid composition, and polishing time can not only make the surface bright, smooth and clean but also enhance the surface resistance. Corrosive, so it is a good way to brighten the surface, of course, its cost and technology will also increase a lot.
The above contents of EP-grade stainless steel pipes are all from the Internet. I hope it will be helpful for your further understanding. If you want to know more about stainless steel, you can click the following to view:
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