Stainless steel pipe is a metal material widely used in industrial and civil fields, it has excellent mechanical performance and corrosion resistance. However, during the processing of stainless steel pipes, it will be affected by various factors, resulting in a decline in its surface quality and performance. 

To improve the surface and internal structure of stainless steel pipes, a common method is bright annealing. This article will introduce the principle and process of bright annealing, and analyze its three major functions for stainless steel pipes: improving brightness, ductility and corrosion resistance. 

Get bright surface without oxidation. Bright annealing is performed in a protective atmosphere or vacuum, which can prevent the surface from contacting air and causing oxide scale, maintain the original metallic luster, and improve corrosion resistance. Since there is no oxidation process in bright annealing, the chromium content on the surface of stainless steel pipes will not decrease, thereby improving its corrosion resistance. Compared with the surface after ordinary annealing or pickling, the surface after bright annealing is more resistant to the erosion.

Eliminate hardness. In the process of cold rolling or cold drawing, stainless steel pipes will produce hardening phenomenon, which will make the material hard, brittle and difficult to deform. Bright annealing can eliminate work hardness, restore the original properties of the material, and improve its ductility and plasticity. 

Obtain a satisfactory metallographic structure. Different stainless steel pipes have different requirements for metallographic structures. For example, austenitic steel requires a uniform austenite structure, and ferritic steel requires fine ferrite grains. Bright annealing can obtain the required metallographic structure by controlling the annealing temperature and time. 

Guangdong Han Technology Co., Ltd. 

Recommended reading: Intelligent bright annealing equipment 

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