How to obtain a non-oxidized bright surface of stainless steel sanitary pipe through bright annealing process

How does the stainless steel sanitary pipe obtain an oxidation-free bright surface through the bright annealing process? The corrosion resistance of the stainless steel sanitary pipe. When the content of Cr is between 17% and 18% and the content of Ti is 0.5%, the dew point of H2 must be lower than -60°C to avoid oxidation of Cr and Ti in the heating range of 800°C to 1150°C. In addition, how to maintain the purity of the shielding gas in the furnace is also a key issue. In this regard, the muffle cover has good sealing performance and will not cause pollution of the protective atmosphere such as the material of the electric heating furnace body, providing a purer environmental space. In addition, the strip steel inlet and outlet of the vertical furnace are located at the lowest part of the furnace, and the furnace pressure is stable. Therefore, compared with the horizontal furnace, the risk of air entering is much smaller. However, the inlet and outlet sealing boxes of the bright annealing furnace, the strip conveying section, the tension adjustment roller and the furnace top guide roller box should be ensured to meet the sealing requirements of a few parts per million (ppM level), so that oxygen and water vapor cannot enter, and the protective gas Bright annealing is not allowed, and the strip steel is heat treated in an H2 protective atmosphere. To meet the requirements of the BA board, the protective atmosphere in the furnace must be very strictly controlled to avoid oxidation as much as possible. How does oxidation occur under H2 protective atmosphere? The main alloy components of stainless steel sanitary pipe material elements are Fe, Cr, Ni, Mn, Ti, Si, etc. In the annealing temperature range, the oxidation of Fe and Ni is not a major problem. However, the oxidation range of Cr, Mn, Si, and Ti is just within the heating temperature range. It is the oxidation of these alloying elements that affects the surface brightness of the strip steel. In particular, the oxidation of chromium will reduce the dechromation of the surface of the strip.