| 摘要 |
PURPOSE:To form a corrosion resistance film on the surface of a heat resistant Fe- Ni-Cr alloy without causing remarkable corrosion due to hot corrosive combustion gas and providing excessive thermal hysteresis by treating the alloy by a powder packing method to diffusion-coat Cr and Si at the same time. CONSTITUTION:A heat resistant Fe-Ni-Cr alloy for a diesel engine, etc. is heat treated in a treating agent contg. Cr powder and Si powder in a nonoxidizing atmosphere to diffuse Cr and Si in the alloy at the same time. For example, an alloy consisting of, by wt., 45% Ni, 45% Cr, 0.05% C, 0.05% Mn etc. and the balance Fe is embedded in a powdered mixture consisting of, by wt., 15% Cr, 12.5% Si, 2.5% NH4Cl,20% Fe and 50.0% Al 2O3 as a packing agent. They are heated at 900 deg.C for about 7hr in an electric furnace in an H2 atmosphere. |
