| 摘要 |
PURPOSE:To improve the corrosion resistance and to prevent the hydrogen embrittlement by preoxidizing hafnium in steam to form an oxide film on the surface. CONSTITUTION:Hafnium is held in an atmosphere of steam at 270-480 deg.C under 0.1-150kg/cm<2> pressure for several 10min- several 10hr to form a dense and homogeneous colored oxide film having superior adhesive strength on the surface of the hafnium. A hafnium substrate having said oxide film formed on the surface shows superior corrosion resistance, and the hydrogen embrittlement of the substrate is prevented. |
