| 摘要 |
PURPOSE:To improve the appearance and color tone of an iron material having a nitrided surface and to increase the surface hardness and corrosion resistance by bringing the material into contact with hot steam. CONSTITUTION:A ferroalloy material subjected to nitriding such as soft-nitriding is placed in an atmosphere contg. about 5-10% steam and brought into contact with heated steam at about 300-600 deg.C for about 5-30min. By this steam treatment a contained metal-nitrogen compound, an intermetallic compound or a solid soln. is produced besides Fe2N-Fe4N and Fe4N structure. Accrodingly, by this method a steel material or a steel product having superior hardness, a fine color tone, superior wear and corrosion resistances is obtd. without removing the white layer. |
