PRODUCTION OF METALLIC MATERIAL HAVING SURFACE LAYER WHICH IS HIGHLY RESISTANT TO CORROSION AND WEAR

摘要

PURPOSE:To obtain the material having a surface layer which is highly resistant to corrosion and wear in high-temp. and high-pressure water environment by previously injecting N ions at a specific ratio into an Fe-based or Ni-based alloy contg. Ti and Cr at specific ratios at the time of heating this alloy in a high vacuum. CONSTITUTION:The N ions are previously injected at 1016 to 1019 pieces/cm2 into the metallic material made of the Fe-based or Ni-based alloy contg., by weight, 0.2 to 1.0% Ti and 13 to 35% Cr. This material is heated at 600 to 1050 deg.C under a high vacuum of =10-4 Torr vacuum degree. The thickness of Ti (N, C) formed on the surface of the material is insufficient and the surface layer which is highly resistant to corrosion and wear is not obtainable if the quantity of the N to be injected at this time is lower than lower limit. The nitrides of Fe and Cr are formed and no contribution is made to an increase in TiN when the quantity exceeds the upper limit. The alloy of =0.03% C in the above-mentioned compsn. may be heated at 600 to 1050 deg.C in a gaseous nitrogen atmosphere of =99,9% concn.