Black Annealed Cold Rolled Steel Coil is cold rolled steel coil goes to the heat treatment. The heat treatment process of recrystallizing cold-rolled coils, eliminating cold-rolling work hardening, and restoring plasticity to obtain the expected physical and physical-chemical properties. The process flow is generally divided into preliminary annealing, intermediate annealing and finish annealing. The annealing process varies with the purpose, and recrystallization annealing, incomplete annealing and complete annealing are often used. In order to obtain a strip with no oxidation and no decarburization on the surface, the strip is brightly annealed in a protective atmosphere.