| 摘要 |
PURPOSE:To improve the corrosion resistance of the black colored layer of a stainless steel material by executing a specific surface treatment and finishing treatment before or after a black coloring treatment in the stage of subjecting the stainless steel material to the black coloring treatment. CONSTITUTION:The stainless steel material is immersed for 2min in a solvent contg. NaOH and after the surface is subjected to a fat treatment, the NaOH soln. is rinsed away. The material is then pickled by immersing the same for 2min in a soln. mixture composed of 60% HCl and 40% FeCl3 and thereafter the surface is rinsed with gushing water flow and is dried, by which the stainless steel material is subjected to the surface treatment. The material is immersed for 15min in an Na2Cr2O7 soln. kept at 460-500 deg.C in succession thereto and is cooled after taking the material out of the soln. to form the black film having the excellent corrosion preventive function on the surface of the stainless steel material. The material is further rinsed with hot water and is dried, then an oil is finally coated on the surface thereof, by which the corrosion resistance of the stainless steel material is remarkably improved. |
