| 摘要 |
PURPOSE:To prevent the de-Cr layer and laps on a surface and to improve the corrosion resistance of a product by omitting a hot rolled sheet annealing stage in production of a thin steel sheet of Cr-contg. steel or stainless steel contg. a specific ratio of Cr, adjusting the atmosphere in the stage of final annealing and specifying pickling conditions. CONSTITUTION:The hot rolled coil of the Cr steel or stainless steel contg. >=5wt% Cr is coiled at 600-800 deg.C and is subjected to mechanical descaling and pickling and descaling with H2SO4 or HCl without annealing the hot rolled sheet. The Cr removed layer on the steel sheet surface is thoroughly dissolved and a desmatting treatment is executed by hot water contg. <=0.5g/l HF and scraper. A coil grinding stage in the mid-way is simply executed or omitted. After the steel sheet is subjected to cold rolling in succession thereof, the final annealing is executed in the annealing atmosphere in the shaded part of A1-A2-A3 or below at the temp. in the shaded part near T1-T2-T3 in the figure. |
