Method for continuous annealing and pickling of high chrome ferritic stainless steel plate

摘要

PURPOSE: A method for continuous annealing and pickling of high chrome ferritic stainless steel plate is provided, which can improve picklability and surface quality of high chrome ferritic stainless steel plate. CONSTITUTION: The method includes the steps of cold rolling a high chrome ferritic stainless steel comprising 0.01 wt.% or less of C, 0.02 wt.% or less of N, 0.5 wt.% or less of Si, 0.5 wt.% or less of Mn, 0.03 wt.% or less of P, 0.004 wt.% or less of S, 0.01 wt.% or less of O, 0.18 wt.% or less of Ti, 0.4 wt.% or less of Nb, 1.0 wt.% or less of Cu, Al 0.03 to 0.13%, 4 wt.% or less of Mo, Cr 20 to 35%, a balance of Fe; annealing the stainless steel strip at 970 to 1,025C; cooling the annealed stainless steel strip below 100 deg.C; dipping the cooled stainless steel strip in a salt bath, wherein the temperature range of the salt bath is 400 to 450C; primary pickling the stainless steel strip in sulfuric acid bath; secondary pickling the stainless steel strip in a mixed acid bath where nitric acid and fluoric acid are mixed.