The typical production process of cold-rolled steel strip hot-dip galvanizing is:
Loading → uncoiling → pinch, straightening → welding → surface pre-cleaning → inlet looper → annealing → hot-dip galvanizing → alloying → cooling → middle looper → smoothing → stretching and bending straightening → post-processing → inspection Take-up.
Continuous annealing furnace shell:
Generally, ceramic fiber outsourcing stainless steel plates are used, refractory bricks and heat-insulating bricks are used for the furnace bottom, and the furnace rolls are driven separately and frequency-converted. Generally, the annealing furnace is composed of a preheating section, a heating section, a cooling section, and a zinc pot inlet section. In the first three sections, a mixed gas of hydrogen and nitrogen is introduced to heat the strip steel to above the recrystallization temperature in this reducing atmosphere, and Heat preservation, soaking, and cooling make the strip steel sealed into the zinc pot for hot-dip galvanizing.
There are two main purposes: one is to achieve recrystallization annealing of the strip to eliminate rolling stress, restore the grain structure, and improve the plasticity of the strip; the second is to make the steel have a clean and oxide-free active surface, so that it has a very High plating adhesion.
Production process of continuous hot-dip galvanizing unit