抄録
In order to improve the high-temperature wear resistance of white cast iron, a cermet powder layer mixed with Ni and/or Cr powder was inserted by molten 27 mass% Cr white cast iron. The microstructures of surface and vertical cross-section of the inserted layer were examined to investigate castability of the molten cast iron. High-temperature wear resistance of the inserted layer was examined by means of a high-temperature compressive impact fatigue test. The results obtained are as follows. (1) The inserted layer with 50 vol. % Ni powder or 25 vol. % Ni and 25 vol. % Cr powder shows satisfactory metallographic structure, though the inserted layer with 50 vol. % Cr powder includes some micro pores and voids. (2) The wear resistance decreases with increasing temperature for whole the inserted layers. The impact fatigue strength of the layer with 50 vol. % Cr powder is highest in whole the inserted layers at higher temperature side. (3) However, the inserted layer with 50 vol. % Cr powder shows many cracks connecting with the micro pores and voids after the impact fatigue test. Therefore, it is important to make an inserted layer without any micro pores and voids by using smaller sized cermet powder.
