| 摘要 |
PURPOSE:To perform descaling easily without damaging heat treating furnace, by heat treating stainless steel material in a specified O2 atmosphere, then adhering aq. soln. of nitrate or ferric salt thereto at a specified temp., next, pickling said material. CONSTITUTION:If stainless steel material is charged into heat treating furnace of atmosphere contg. >=5% O2, then heat treated at about 1,100-700 deg.C, oxide film is formed on the surface of steel material. The steel is cooled to 700-300 deg.C, then aq. soln. of nitrate or ferric salt is adhered to said surface. Aq. soln. of these salts is penetrate into fine crack in scale, and the state easy for descaling is provided. Consequently, scale is removed simply by pickling in the following process. By the method, descaling is carried out easily, even if material contg. Pb in Cr stainless steel is used.
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