Development of a fast annealing pickling technology for cold rolled stainless steel strips

A new heating technology using a combustion furnace with impinging flame burners has been developed for annealing cold rolled stainless steel strips, This technology not only improves the efficiency of the annealing, but also facilitates the descaling after annealing. The rapid heating of TP304 stainless steel with the burners, followed by the short soaking, enables us to get a thinner scale which can be dissolved easily by the anodic electrolysis in a sodium sulphate solution and subsequent immersion in nitric-hydrofluoric acid solution, Stainless steel strips of 1 mm gauge are now produced at a rate of about 70-80 m/min.