Definition of bright annealing
Light annealing (BA) refers to the heating of stainless steel materials in a closed furnace in an inert gas reducing atmosphere. Hydrogen is common. After rapid annealing and rapid cooling, the outer surface of the stainless steel has a protective layer that does not reflect in the open environment. This protective layer can resist corrosion. Generally speaking, the surface of the material is smoother and brighter.
Requirements before bright annealing:
The surface of the pipe must be clean and free of other foreign substances. Any substance left on the surface of the pipe will cause damage during processing.
Inserted gas for bright annealing
The annealing atmosphere should be free of oxygen and isolate the material to form a vacuum state. Inserted gas, ordinary dry hydrogen or arsenic, can obtain a bright effect.
Bright annealing temperature
Pay attention to the annealing temperature. Depending on the grade of stainless steel, the annealing temperature of austenitic steel is at least 1040 degrees, and the immersion time is not important. High temperature must have a bright appearance. The faster the heating, the better. Slow heating can lead to oxidation. Some ferritic stainless steels require lower annealing temperatures, such as TP439, but cannot be bright annealed effectively. Water quenching can lead to scale formation.
Bright annealed stainless steel pipe
