| 摘要 |
PURPOSE:To provide a material for metallic mold having fine voids over the whole surface and controllability to the hardness in heat treatment without damaging machinability and corrosion resistance by pressurizing and compacting a mixed material prepared by adding powder of copper, etc., to short fibers and powder of ferritic stainless steel and executing nitriding treatment after sintering. CONSTITUTION:The mixed material is prepare by adding the ferritic stainless steel powder and the copper powder or Cu-Sn powder to the short fibers having 30-300 aspect ratio, which is obtained by cutting the ferritic stainless steel long fiber having <=100mum diameter manufactured with a wire cutting method. This material is uniformly packed into a rubber mold for CIP method, and after compacting this at 2-4ton/cm<2> pressure, this is heated in the vacuum atmosphere and sintered. By continuously heating or reheating and holding this at the temp. of 900-1050 deg.C in nitrogen gas or ammonia cracked gas, the content of nitrogen in the base metal is regulated to 0.3-1.2wt.% and the above material for metallic mold is manufactured. |
