| 摘要 |
PURPOSE:To simultaneously enhance the wear resistance of steel parts and the corrosion resistance at high temp., by forming a diffused Ni-Cr alloy layer on the surface of each of the parts and by nitriding the layer. CONSTITUTION:Ni is deposited on the surface of each of steel parts using a gaseous nickel halide and diffused, and Cr is diffused by chromizing to form a diffused Ni-Cr alloy layer contg. 20-70% Ni and 25-80% Cr and having >=5mum thickness. The layer is heated to 1,000-1,300 deg.C in an atmosphere of gaseous nitrogen or a decomposed gas of ammonium carbonate to incorporate 0.1-2wt% N into the layer, and hard chromium nitride is deposited on the surface to improve the erosion resistance. |
