With the widespread use of stainless steel pipes, people's demands for product applications are getting higher and higher. Some users require deep processing of stainless steel pipes, which requires bright annealing. Below, HUASHANG STEEL will introduce what is the discount bright annealed seamless steel pipe and the purpose of bright annealing for stainless steel pipes.
First, let's understand what a bright annealing is. The definition of bright annealing is: the annealing process of metal materials or workpieces in a protective atmosphere or vacuum to prevent oxidation and maintain a bright surface. For stainless steel pipes, after cold rolling through a 3-roll mill at room temperature, the surface hardness of the steel pipe will become much harder, which affects the next process and the continued processing. However, this requires high-temperature annealing to eliminate the hardening effect. Therefore, bright annealing is one of the key steps for the performance of stainless steel pipes, mainly by heating and annealing in a closed space, allowing the temperature to slowly cool to below 500℃ in the closed space, and then naturally cooled, which will cause brightness without causing decarburization.
After the stainless steel pipe is bright annealed, it eliminates work hardening and obtains satisfactory metallographic structure. When the performance requirements are different, the requirements for the metallographic structure after bright annealing are different, and the bright heat treatment process is also different.
Since bright annealing is a heat treatment process for stainless steel pipes in a mixed gas of hydrogen and nitrogen, the surface of the stainless steel pipe can be obtained with a non-oxidized, bright surface by strictly controlling the protection atmosphere in the furnace, especially the purity, residual oxygen, and dew point. Compared with the surface obtained by normal annealing and pickling, the poor chromium phenomenon on the surface of discount bright annealed seamless steel pipes is reduced because there is no oxidation process, and its corrosion resistance is better than that of 2B plates after polishing. Therefore, a non-oxidized, bright, and corrosion-resistant surface can be obtained.
In general, after the bright annealing treatment, the pipe material can maintain the surface finish and precision of the rolling surface and can get a bright surface without further processing. The surface of the discount bright annealed seamless steel pipe retains the original metal luster and has obtained a bright surface close to a mirror surface. Under general requirements, its surface can be used directly without further processing.
The above content is the definition of bright annealing and the purpose of bright annealing for stainless steel pipes. We have learned that bright annealing for stainless steel pipes can eliminate work hardening and obtain satisfactory metallographic structure; obtain a non-oxidized, bright, and corrosion-resistant surface. In addition, bright annealing basically does not affect the surface finish and precision of the steel pipe.