Common types of continuous annealing furnaces for
stainless steel strips include horizontal and vertical types. Because the indirect heating of vertical annealing furnaces has corresponding advantages in strip surface quality control, it has developed rapidly in recent years, while horizontal continuous annealing furnaces The tension in the furnace is smaller than that of the vertical furnace, which is more suitable for the production of stainless steel, so it has been adopted by many stainless steel factories.
In the annealing process of cold-rolled austenitic stainless steel, the annealing temperature and holding time have important effects on the microstructure and mechanical properties of the metal. When the stainless steel strip is annealed at about 1050°C, the carbon compounds in its metallographic structure will all dissolve into the matrix and be uniformly dispersed inside the grains, and the grain size is also relatively uniform. The yield strength and tensile strength of the material vary with With the extension of the holding time, it also shows an upward trend, but when the annealing temperature is greater than 1050 ° C, the yield strength and tensile strength of the material will show a downward trend with the extension of the holding time.
The cooling process of the stainless steel strip after annealing has a great influence on the performance and shape of the finished stainless steel strip. For stainless steel strips of different steel types and plate thicknesses, it is necessary to scientifically and reasonably control the cooling rate and cooling uniformity.
Among them, the cooling rate of austenitic stainless steel is closely related to the carbon content, and the cooling rate should be correspondingly accelerated with the increase of the carbon content. The precipitation of carbides at the grain boundaries will cause sensitization, which will weaken the corrosion resistance of stainless steel strips, so rapid cooling treatment is required in this temperature range.
For ferritic stainless steel, in order to control and keep the temperature uniform, it is not suitable to adopt quenching treatment, and it should be cooled with a small temperature gradient as much as possible when the process allows.
