Oxidation Behavior of Inconel 617 Surface Treated by AI-Pack Cementation

Abstract

Inconel617 is a candidate material for the high temperature applications such as turbine blades, structural materials for nuclear reactors, and high-temperature gas-cooled reactors. In this work, thε oxidation behavior of Inconel 617 after AI-pack cementation was studied by exposure to air for 1000 hr at 950oC. AI, pack cementation was carried out at 800oC - 1000oC for 1 h in Ar using an AI203 crucible containing the specimen and a powder mixture of AI : AI203 : NH4CI = 15g: 83g : 2g. The coating layer phase after AI-pack cementation was confirmed as NiAI and Ni2AI3 by EPMA and XRD. The thickness of coating layer was increased with increasing temperature. After exposure at 950oC, the phase analysis of coating layer was carried out by TEM, SEM, and EPMA. The hardness of coating layer was measured by nanoindentation. The oxidation resistance and hardness of surface after AI-pack cementation have improved.